Honda CX500 & GL500 Forum

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07-12-2009, 5:24 AM midgtmn Joined on 02-19-2009 Rochester, NY - USA Posts 285 Got a 2nd CX, 81 CX500 Custom! Now I have to get it to RUN Well, I bought a second CX: A 1981 CX500 Custom. It's a pretty incredible example I think. The previous, previous owner (if that makes sense), put a LOT of money and parts into this bike. It has real good chrome on everything but the mufflers. The paint is perfect on the tank, only one side cover is damaged. Small tear in the seat cover.  New Bridgestone  Qualifiers front and rear (rear is over-wide, not sure if I like that). The bike came with a folder with the title (yay!), and the receipts for everything the guy put into the bike, including the Yamaha Mechanical seal (this someone's old bike from the forum?), new cam chain, new tensioner, rewound stator, new plugs. All this for $750. Of course, there has to be a catch: It doesn't run. The guy I bought it from couldn't figure out why. So far, it has me stumped, too. I pulled the carbs, cleaned them up well. They started pretty clean, and were jetted to 78/117.5 (never heard of that combo.) It also seems like some PO clipped a wind or two off the slide springs. I swapped in stock 115 jets from my spare carbs, and the springs from the spare carbs just so that I started with the stock baseline. Checked spark on both sides, and it seems good sometimes, but seems sketchy sometimes. It has backfired a few times starting normally, but other times won't even pop when I spray carb cleaner in the vacuum gauge hole in the intake boot. Pulled the plugs, and they were wet with fuel, and would spark outside the cylinder. Someone has swapped on new plug boots, but the capacitors and leads seem original. My current theory is replace the leads (which are sealed to the capacitors, right? I have to replace both the caps and the leads). Anyone have a source for new caps/leads? '78 CX500 - Back from the brink! '81 CX500C- Finally Running thanks to Ignitech!    Report

07-12-2009, 5:37 AM Shep Joined on 01-30-2007 UK.2x1980CX500A Posts 7,635 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2) Great deal and I think and the Customs really do look nice :) My Music http://www.reverbnation.com/pauldouglas/ Join Just In Case :) http://globalcxglvtwins.hostingdelivered.com/ Id quot circumiret, circumveniat    Report

07-12-2009, 7:38 AM Blue fox Joined on 04-18-2008 COLUMBIA, MISSOURI Posts 1,533 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2) Very nice looking bike.  I assume you have tried different or new sparkplugs?  They can sometimes go bad with the gas we are getting now.  I have had good results with a puff of starting fluid into the air cleaner opening before cranking.  Might try that.  Compression OK?  I doubt the high tension leads are causing the problem.  I don't think coils just go half bad.  If they make a spark with the plug out, they don't have a internal issue.  There are cases where the heat from the engine will affect the coil operation, but we don't have any heat yet.  Do you have a spare CDI to swap out?  Maybe the coils are not getting enough current from the CDI to fire properly.  You could also do a stator check and see how much voltage the CDI is recieving.  Keep plugging away, I don't think you have a serious issue.  Just need to identify whats wrong.  Blue Fox 1983 GL650I, 79-CX500C, 1980 CX500C, 82-GL500I, 82-GL1100, 76-CB550, 81-CB750C, 73-CB350F, 71-CT90,    Report

07-12-2009, 10:50 AM midgtmn Joined on 02-19-2009 Rochester, NY - USA Posts 285 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2) I swapped over a plug from my 78, and it sparked ok. What concerns me about the leads is that changing the bend in the lead can cause it to start or stop consistently sparking. I reseated the boot into the lead, but it didn't change much. The lead seems to have very few copper strands for the screw in the boot to dig into... Compression is at least "ok", though I havn't gotten to test it. Could feel significant vacuum when plugging the vacuum gauge hole in the intake boot with my finger. It's funny... I know how a CDI works, the whole ignition, but I have no idea what the CDI box actually looks like... anyone got a simple description, I assume I can just trace back from the wires on the coils, I just havn't gotten a chance to go look. Thanks for the help '78 CX500 - Back from the brink! '81 CX500C- Finally Running thanks to Ignitech!    Report

07-12-2009, 12:08 PM Shep Joined on 01-30-2007 UK.2x1980CX500A Posts 7,635 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2) They came in Gold/Black and sometimes Silver but all the same inside, The CDI coils are different from the TI ignition engines and cannot be swapped.The CDI coils HT(Hight Tension) leads are hard wired into the Coils so it usually means getting another coil assembly but depending on where the break is HT connectors can be used as a repair. Also, http://globalcxglvtwins.hostingdelivered.com/viewforum.php?f=8 My Music http://www.reverbnation.com/pauldouglas/ Join Just In Case :) http://globalcxglvtwins.hostingdelivered.com/ Id quot circumiret, circumveniat    Report

07-12-2009, 12:33 PM Blue fox Joined on 04-18-2008 COLUMBIA, MISSOURI Posts 1,533 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2) The CDI box is located under the seat in recess.  It is usually either black or natural metal color and is about 3 x 3 and 1" thick.  But if you can change the sparking characteristics by bending the HT lead, sound like you may have identified the problem area.  While you are at it, remove the plug boot and unscrew the connector that fits on the plug.  Inside you should find a resistor (about 3//4" long), a rod, and a spring or maybe two.  Different models have different parts.  Everyone recommends discarding the resistor, and replacing it with a brass, aluminum, or copper rod of equal length.  Also make sure there is no corrosion in the bottom of the hole.  Reassemble everything and maybe cut 1/8" off your HT lead.  Don't do too much, they are usually short already.  If you have a meter, you should be reading very low or no resistance thru your plug cap before you screw it on.  It is generally accepted that the high tension wire is non-replaceable on the CDI model bikes, folks have tried to replace with solid core plug wire by cutting the lead close to the coil and soldering and shrinkwrapping it in place.  If you do a neat job, it may work.  Just make sure your splice is as far away from any metal on the frame as possible.  Once you break the insulation, you have opened up a path for the spark to jump. Blue Fox 1983 GL650I, 79-CX500C, 1980 CX500C, 82-GL500I, 82-GL1100, 76-CB550, 81-CB750C, 73-CB350F, 71-CT90,    Report

07-15-2009, 6:17 PM midgtmn Joined on 02-19-2009 Rochester, NY - USA Posts 285 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2) Thanks for all the info guys. I swapped CDI between my 78 and the 81, and the 81 still doesn't run, and the 78 runs fine. Seems to prove that the CDI is not the culprit. Next up I am thinking of swapping coils (probably only good coils from the 78 to the 81) and see if that works. The 81's coil leads have brand new NGK plug boots on them, so no more resistor to worry about (though now the rain can get in... doh, guess the PO can't be perfect) Any danger in doing the swap? I know they are different form factor (the 81 is under the spine, the 78 is alongside the spine). I planned on jury rigging them so they wouldn't arc or anything, and just using them for testing purposes. '78 CX500 - Back from the brink! '81 CX500C- Finally Running thanks to Ignitech!    Report

07-17-2009, 7:23 PM midgtmn Joined on 02-19-2009 Rochester, NY - USA Posts 285 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2) So I am greatly confused at this point... I swapped the coils from the 78 (the good running bike) to the 81 (the not running bike). They fit into the under-the-spine holder just fine, and I hooked them up to the correct cylinders. Hooked up fuel tank, watched fuel flow through semi clear fuel hose into carbs as I hit the starter button (vacuum op petcock doing it's thing).  I have consitent good spark on the left plug, which I pulled and tested against the crankcase. It smelled of gas and appeared wet when I first pulled it (tried starting before pulling plugs.When I reinstalled the plugs though, no pop running on the carbs, and no pop from a quick squirt of carb cleaner into the chamber that I did just before reinstalling the plug. I then pulled the air box cover off, and sprayed some carb cleaner into the air box. Still no pop at all coming from the bike. I hit the air box with a bit more carb cleaner again, and while under constant starter running, I got a gunshot loud backfire through the pipes, I am still part deaf in my right ear, and it pulled my housemates to the garage to see what was up. I am pretty lost here, I have spark (outside the case at least, and once inside - gunshot, working CDI and coils swapped to the bike), I have fuel (both gas and carb cleaner), and I have air (carb cleaner got in from the airbox I would assume, there is also vacuum at the intake boot manometer hookup). This should all add up to SOMETHING coming from this bike. My only other thoughts are some sort of REALLY terrible mishap in the timing. Anyone have any direction to point me? I'm fine with being told I'm wrong, maybe one of my assumptions is off... In any case, it's was a good vent. Thanks in advance! '78 CX500 - Back from the brink! '81 CX500C- Finally Running thanks to Ignitech!    Report

07-17-2009, 8:53 PM lucky Joined on 03-06-2009 kingman az age 26 Posts 1,443 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2) have you taken the plugs out and then turned the bike over because from what it sounds like right now its flooded take the plugs out if you have a air compressor with an air gun attachment i would use that to blow the cylinders dry then go to an auto parts store and get some starting fluid and then when you get home go light a cigarette (if you smoke) then put the plugs in and then spray some start fluid on the air filter maybe but just maybe it might work but honestly thou it sounds like its flooded HTH  1982 honda cx500c 1979 honda xr185 dirt bike If you can read this thank a TEACHER If you're reading this in ENGLISH thank a SOLDIER http://globalcxglvtwins.hostingdelivered.com/    Report

07-18-2009, 2:51 AM Shep Joined on 01-30-2007 UK.2x1980CX500A Posts 7,635 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2) Although you have fuel coming through don't assume it's good.What 1st appears to be an ignition problem may well be carb related.If the floats are sticking open or at an incorrect height they can give the same symptoms by flooding. Check Here My Music http://www.reverbnation.com/pauldouglas/ Join Just In Case :) http://globalcxglvtwins.hostingdelivered.com/ Id quot circumiret, circumveniat    Report

07-22-2009, 7:47 PM midgtmn Joined on 02-19-2009 Rochester, NY - USA Posts 285 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2) Thanks for the hints, but no dice yet :( I have pulled the carbs from my 78, and put them on the 81. The 78 ran great with these on, they have gone through 2 complete cleanings (including float height set using calipers, metal tab floats on the 78!).  Reconfirmed spark, both sides fire consistently and brightly, including when grounded to the head directly.  I aired out the cylinders by leaving the plugs out for a good while, but admittedly didn't push compressed air through. The 81 still won't run! No heat at all at the headers, only fuel smell in the exhaust. Still seems to not be igniting, either by too much/too little fuel, or the spark disapearing when the plugs are actually in the cylinders. I opened up the valve covers, and they are all working right. We even tried to check the timing visually, but it was too hard to tell by eye. I'm going to try again after blowing out the cylinders tomorrow, but my next move will probably be into timing concerns. The engine has green case gaskets, and a service history that includes receipts for new cam chain tensioner and stators, so the whole case has been apart before. If it is firing at Bottom Dead Center or something, fuel really needs the compression to ignite by spark. Are there any easy ways to put a timing light to these bikes? with the CDI powered by the stator I'm just having trouble figuring out if a timing light would actually work... any ideas on this would be appreciated! The ordeal goes on, but my resolve to make this beauty run is still kickin'  ;) '78 CX500 - Back from the brink! '81 CX500C- Finally Running thanks to Ignitech!    Report

07-22-2009, 9:55 PM mikemagoo86 Joined on 05-11-2009 Warwick, RI Posts 161 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2) Pretty beautiful looking cosmetically I must say, congratulations on the find and good luck getting it up to speed! ~mike "Truth suffers from too much analysis" ~Dune Messiah, by Frank Herbet 1980 CX500 D "My pain in." 81C carbs = fantastic thanks to Larry in CA 1982 GL500 Parts for sale...fairly rough shape but the engine/carbs/ignition seem solid.    Report

07-23-2009, 1:11 AM Shep Joined on 01-30-2007 UK.2x1980CX500A Posts 7,635 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2) Possible Kill Switch fault?Grounding to the frame somewhere?The B/W wire also runs at the top near the Air Filter box from the kill switch. I'd also replace the main fuse holder and fuse, http://globalcxglvtwins.hostingdelivered.com/viewtopic.php?f=8&t=27 My Music http://www.reverbnation.com/pauldouglas/ Join Just In Case :) http://globalcxglvtwins.hostingdelivered.com/ Id quot circumiret, circumveniat    Report

07-23-2009, 5:38 AM midgtmn Joined on 02-19-2009 Rochester, NY - USA Posts 285 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2) I will check the kill switch, though I have played with it while checking spark outside the head, and it seems to work properly. I have already replaced the main fuse with an automotice ATC fuse holder. All the lights and signals are bright and functional, so it seems like the voltage source is good. I'll keep digging and post more tonight! '78 CX500 - Back from the brink! '81 CX500C- Finally Running thanks to Ignitech!    Report

07-23-2009, 5:56 AM Bearman1 Joined on 04-03-2009 Rockdale, Illinois-58 Posts 400 Re: Got a 2nd CX, 81 CX500 Custom! Now I have to get it to RUN I have oft times wondered about the timing on these bikes. Not that I am having any troubles with mine ('81-gl500), but, am interested, in just where the timing mark/s are and how 1 would go about adjusting, or, in this present case merely check to see if the valve timing is ko-pa-setic with the ignition timing. Thanks '81 GL-500 35 1/2k 63,500 to go LTWRD    Report

07-23-2009, 6:23 AM Blue fox Joined on 04-18-2008 COLUMBIA, MISSOURI Posts 1,533 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2) Nice looking bike.  Could it be that it started and runs so sweet that you can't even tell it's running?  I know I have to start my Hondas up before my brother-in-law starts his Harley, otherwise I can't tell if mine is running.  OK, bad jokes, back to the problem. I have not tried this, but I think you should be able to hook a timing light up to one cylinder and get at least an idea of where it is firing by pointing it into the inspection hole.  I think you are on the right track with timing issues.  The only way timing can be off is Woodruff key on rotor missing or sheared, pulsar coils reversed, or timing chain improperly installed. So try putting a wood dowel or equiv into one of the sparkplug holes and remove the valve cover.  See if the valves are closed and a little loose when that cylinder is at TDC on compression thru the inspection hole.  You may have to go 180 degrees to make sure.  That should indicate that there is proper conjunction of the crankshaft and the valve train.  It may not show if the chain is one tooth off tho, that may require removing the rear cover. Next, try hooking up the coils backwards.  That is, reverse your coil leads coming out of the CDI.  If the PO has somehow reversed the pulsar coils, this may reverse that situation to a degree.  I don't know for sure if this would put everything back into correct timing, it depends on how the pulsar coil is internally made as to when the magnetic button passes by the coil.  But it shouldn't hurt anything.  Third idea would be to sell it to me for $100 and transfer the problem! Blue Fox 1983 GL650I, 79-CX500C, 1980 CX500C, 82-GL500I, 82-GL1100, 76-CB550, 81-CB750C, 73-CB350F, 71-CT90,    Report

07-23-2009, 9:25 AM Shep Joined on 01-30-2007 UK.2x1980CX500A Posts 7,635 Re: Got a 2nd CX, 81 CX500 Custom! Now I have to get it to RUN  Bearman1 wrote: I have oft times wondered about the timing on these bikes. Not that I am having any troubles with mine ('81-gl500), but, am interested, in just where the timing mark/s are and how 1 would go about adjusting, or, in this present case merely check to see if the valve timing is ko-pa-setic with the ignition timing. Thanks The way Honda have designed the bikes only in extreme circumstances can the bikes go out-of-time and then not by much if at all.The timing is set by the fixed pulsars around the Stator and the Advance and retard by a,"Hall Effect" set of coils in the rear of the engine induced by the small magnet in the crank shaft end-cap that spins inside them and then by the CDI box.There is little or no adjustment allowed or needed as per the manual.Basically it's a rock solid timing system :) If you can get a timing light to work and shine it in the rear Crank case inspection hole you may be able to see it in operation but it wouldn't really tell you much unless some one had put the cam chain on incorrectly. My Music http://www.reverbnation.com/pauldouglas/ Join Just In Case :) http://globalcxglvtwins.hostingdelivered.com/ Id quot circumiret, circumveniat    Report

09-22-2009, 10:36 AM midgtmn Joined on 02-19-2009 Rochester, NY - USA Posts 285 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2) So, after much time off from it, I have done more tests on the 2nd CX. using a long screwdriver in the spark plug hole, I confirmed that the flywheel markings are correct to the pistons themselves. TR goes by when the right is at TDC, and TL for left TDC. Also checked valve timing to the flywheel. As TR comes by (on the right stroke), the intake valves close up (now all valves closed), combustion stroke, then exhaust valves open. So, it seems that the mechanical timings are correct, at least as far as my knowledge can go. I did all my turning of the engine from the nut on the end of the crank, and I took it slow. To answer Blue Fox, I have swapped the ignition left to right by cross-connecting the LT leads to the coils (yellow to pink, pink to yellow, instead of matching colors). This had no noticeable effect. Back to electrical timing or ignition then. Spark still happens clearly and regularly when the plug is outside the cylinder, grounded to the block. Timing light does not work. I think this is a limitation on the sensitivity of the timing light, because it would read just fine on my running 78 CX. My theory is that with the starter turning the engine, the plugs still fire (I can watch them do so), but don't put out enough current to make an inductive timing light trigger. (the magnetic fields around the wire are what trip the inductive pickup on the timing light, those magnetic fields require large swings in current to actually be strong.) I pulled the cover on the stator at the back of the engine (no easy task with the engine still in the bike haha). In comparing it to my spare parts engine, everything is assembled the same way, except that the stator wires are routed slightly differently on the coil itself. I can't see any other way for it to fit, however. Anyone have any tips at this stage? Anything I might have missed with my checking of the mechanical timing? Am I looking at the right part when I look at the coil just under the stainless steel cover at the back of the engine next to the coolant overflow tank? '78 CX500 - Back from the brink! '81 CX500C- Finally Running thanks to Ignitech!    Report

09-25-2009, 5:23 AM The Accidental Mechanic Joined on 08-23-2006 Posts 76 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2) Nice bike; be a shame not to get it running.. How's the rectifier? Have you tested it?    Report

09-25-2009, 6:40 AM Blue fox Joined on 04-18-2008 COLUMBIA, MISSOURI Posts 1,533 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2) Veeeery interesting.  You only need 3 things to make a engine run:  spark at the right time, fuel, and compression.  And you seem to have covered those bases.  But there has to be something missing still from the equation.  Have you actually checked compression with a gage?  The engine should run with 100# plus of pressure,  with 170# being perfect. I am betting on the spark being weak or non-existent with the plugs installed.  It takes much more energy to fire under compression than it does out in the open air.  Here is what I would try:  Make sure you are using good plugs, even new ones can be bad.  Then slide the rubber grommet that covers the top of the valve covers at the plug up so you can look into the plug recess.  Try cranking and see if there is a lightening storm happening around the plug.  Maybe a bad plug cap?  If that looks normal, try closing the plug gap.  A smaller gap makes the spark easier to jump.  I don't think fuel is the issue, with starting fluid, you can make a concrete block run if you have a proper spark.  I think your spark is "jumping ship" before it can fire the plug.  You also mentioned earlier that moving the HT wire changed the spark characteristic.  Zero in on that area.   Blue Fox 1983 GL650I, 79-CX500C, 1980 CX500C, 82-GL500I, 82-GL1100, 76-CB550, 81-CB750C, 73-CB350F, 71-CT90,    Report

03-10-2010, 11:44 AM midgtmn Joined on 02-19-2009 Rochester, NY - USA Posts 285 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2) Resurrecting an ancient thread... but now that it's warmed up a bit I am diving back into making this baby run. I put the battery back in, and once more tested the spark. It is still sparking great on the plugs that were in the head, when putting the plug thread against the head. I am either borrowing a compression tester, or will be buying one in the next couple days to double check that. What amazes me still, is that I have good spark outside the head, and it still won't so much as pop while spraying starter fluid directly onto the intake valves while turning it over. Are there common things that might prevent the plug from making contact while screwed into the head? I couldn't see any spark jumping when I looked down alongside the boot. I also kind of assume that the act of threading the plug in would scrape away anything that would prevent it from making good electrical contact. I guess the real test remains with compression, then further testing of the spark.Wish me luck hah. '78 CX500 - Back from the brink! '81 CX500C- Finally Running thanks to Ignitech!    Report

03-17-2010, 4:26 PM midgtmn Joined on 02-19-2009 Rochester, NY - USA Posts 285 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2) Still haven't tracked down a compression tester yet, but that is in the works. In the meantime I got an inline spark indicator light, like below: Lo and behold... it lights up consistently and brightly with the plug installed in the head, but once again, no burning of starter fluid. My next question, are these bikes waste spark? Meaning, does the spark plug on the right cylinder fire after the compression stroke (like it should), and also during the exhaust stroke (because the cylinder is once again at TDC or so)? Getting real close to pulling the whole engine and having a look inside, I can't figure out any more tests! '78 CX500 - Back from the brink! '81 CX500C- Finally Running thanks to Ignitech!    Report

03-17-2010, 4:46 PM Shep Joined on 01-30-2007 UK.2x1980CX500A Posts 7,635 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2) Looking back the bike has not run and you said the PO didn't know why.Maybe someone worked on the engine and didn't set the valve timing/cam-chain correctly? Also could be a faulty Advance and retard mechanism. White and Blue wires at the main connecting blocks near the CDI Mine read to frame White 360 ohms Blue 450 ohms. If either is away from these by a large margin then it's most likely a wire breakdown to the Advance and Retard unit or the Advance and retard unit Pulsar coils have failed.Hopefully it's not a problem with the Main ignition pulsars.Although the manual states you can remove the Rear AAR cover with the engine in in practice it's not really possible,Easier to move the engine forward or drop the engine completely so you can align the replacement easier.Once you can get to the old one you can test it correctly.Should be 185 to 225 ohms to ground at the plate.I'm running one a little off ths spec but still works fine. My Music http://www.reverbnation.com/pauldouglas/ Join Just In Case :) http://globalcxglvtwins.hostingdelivered.com/ Id quot circumiret, circumveniat    Report

03-17-2010, 5:10 PM Honda_Nut Joined on 03-08-2010 Montana Posts 21 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2)  midgtmn wrote: Still haven't tracked down a compression tester yet, but that is in the works. In the meantime I got an inline spark indicator light, like below: Lo and behold... it lights up consistently and brightly with the plug installed in the head, but once again, no burning of starter fluid. My next question, are these bikes waste spark? Meaning, does the spark plug on the right cylinder fire after the compression stroke (like it should), and also during the exhaust stroke (because the cylinder is once again at TDC or so)? Getting real close to pulling the whole engine and having a look inside, I can't figure out any more tests! Pull that spark plug and rest it against the head. put your hand over the top of the head and see if your spark is happening on the compression stroke. My bet is the wires to the coils are reversed or the timing chain is off 180 degrees. 1980 CX500C 68k Miles 1981 GL500i    Report

03-17-2010, 5:17 PM Shep Joined on 01-30-2007 UK.2x1980CX500A Posts 7,635 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2)  Honda_Nut wrote:  midgtmn wrote: Still haven't tracked down a compression tester yet, but that is in the works. In the meantime I got an inline spark indicator light, like below: Lo and behold... it lights up consistently and brightly with the plug installed in the head, but once again, no burning of starter fluid. My next question, are these bikes waste spark? Meaning, does the spark plug on the right cylinder fire after the compression stroke (like it should), and also during the exhaust stroke (because the cylinder is once again at TDC or so)? Getting real close to pulling the whole engine and having a look inside, I can't figure out any more tests! Pull that spark plug and rest it against the head. put your hand over the top of the head and see if your spark is happening on the compression stroke. My bet is the wires to the coils are reversed or the timing chain is off 180 degrees. The timing chain cannot be 180 Deg out on these bikes unless fitted completely wrongly.If the chain is aligned to the correct marks as per the manual the bike/valve timing is automatically correct. Also using the Cylinder head covers to test spark plugs on a CDI ignition bike is not recommended as they are semi-insulated from the frame.Better to use a actual cylinder head or a port of the frame or even a piece of wire wrapped around the plug and then to a good frame point. HTH :) My Music http://www.reverbnation.com/pauldouglas/ Join Just In Case :) http://globalcxglvtwins.hostingdelivered.com/ Id quot circumiret, circumveniat    Report

03-17-2010, 5:22 PM DaveF Joined on 06-11-2008 Lawrenceville, GA Posts 1,232 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2) A timing light can be used to tell if the electrical timing is grossly wrong. My Web Site 1982 GL500 1983 GL650    Report

03-17-2010, 5:54 PM midgtmn Joined on 02-19-2009 Rochester, NY - USA Posts 285 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2)  Shep wrote: Also using the Cylinder head covers to test spark plugs on a CDI ignition bike is not recommended... I always test by pulling the plug back and putting it against the flange where the carb boot mounts to the head, I noticed the Valve Covers being completely gasket isolated.  Honda_Nut wrote: Pull that spark plug and rest it against the head. put your hand over the top of the head and see if your spark is happening on the compression stroke. I have done this test before, to the best of my abilities to see (without a timing light) it fires at TDC each time.  DaveF wrote: A timing light can be used to tell if the electrical timing is grossly wrong. I have tried using an inductive timing light, and it worked great on my running 78 CX and my car, but the leads on the 81 never triggered it, even when they were sparking. The starter running pulls down the voltage too much I think. I'm not sure if that has implications on it's own... but spark is spark, at least as far as basic "running" goes, and the 81 has not had any problems sparking recently. I understand there is much more than that to it, but in a basic sense, any spark should make a proper air fuel mixture burn.  Shep wrote: White and Blue wires at the main connecting blocks near the CDI Mine read to frame White 360 ohms Blue 450 ohms. I think we might be on to something here... Mine read a paltry 96 ohms on the White, and 177 on the Blue. I checked this using battery negative terminal as the reference, and again using the engine case. I have another pulsar in my spare engine, I will have to meter that and find out what condition it is in. I am hesitantly hopeful that I might have found the culprit... but we shall see. Thanks for all the quick replies guys. '78 CX500 - Back from the brink! '81 CX500C- Finally Running thanks to Ignitech!    Report

03-29-2010, 6:31 PM midgtmn Joined on 02-19-2009 Rochester, NY - USA Posts 285 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2) I checked my working '78 CX - Both leads read just over 400 ohms. Perfect. Spare engine? About 395 apiece. Anyone think it would be a waste of time to crack the spare and put it's pulsar into the 81? Should I look for a replacement, or would I be hard pressed to find one better than the spare I have? I'll probably crack the spare engine in the next day or two, no harm in doing that. But before I drop the engine on the 81 and crack it open, any tips for me or pitfalls to avoid? Thanks in advance guys! '78 CX500 - Back from the brink! '81 CX500C- Finally Running thanks to Ignitech!    Report

03-31-2010, 12:49 AM spanish bandit Joined on 02-12-2009 southern spain Posts 4,999 Re: Got a 2nd CX, 81 CX500 Custom! (or... sating the addiction, pt 2)  midgtmn wrote: I checked my working '78 CX - Both leads read just over 400 ohms. Perfect. Spare engine? About 395 apiece. Anyone think it would be a waste of time to crack the spare and put it's pulsar into the 81? Should I look for a replacement, or would I be hard pressed to find one better than the spare I have? I'll probably crack the spare engine in the next day or two, no harm in doing that. But before I drop the engine on the 81 and crack it open, any tips for me or pitfalls to avoid? Thanks in advance guys! for every millimeter that you pull the rear cover off....push the gear shift back in the same amount.or you risk destroying the spring good luck when i feel the need,i do it,llego,ve 60,s ----------------------------- 2008.1982 honda gli silverwing [uk model ] 2010.1981 honda gli silverwing [uk model ]    Report

04-03-2010, 3:05 PM midgtmn Joined on 02-19-2009 Rochester, NY - USA Posts 285 Re: Got a 2nd CX, 81 CX500 Custom! Now I have to get it to RUN Thanks for the tips guys, but for now I can finally say I have the problem solved! Given that my pulsars worked well enough to get me some spark outside the head... the pulsars weren't totally dead. I figured they would put out enough juice to let the Ignitech Ignition trigger. So I swapped in the Ignitech, tied the +12v direct to the battery for testing purposes, and sprayed some starter fluid in the intakes. Tap the starter... and it fires and turns over a few times! That is more than this thing has done since July 2009! Me and my buddy then formally installed the Ignitech, and put coolant bottle back in, the advance pulsar back on, reinstalled the carbs, reinstalled the tank, and finally put the seat back on. After one minor problem with the vampire tap included with the Ignitech, she fired right up! I've ridden it around the driveway, and it performs well so far. A slight hesitation upon cracking the throttle, so the carbs might still need some work. All in all though, the Ignitech was a cheater's fix, but a darn effective one! Much better than spending a day cracking two engines and whatnot. Instead of that, I spent the afternoon wandering the trails along the river looking at wildlife. Only remaining issue: The Custom handlebars are just terrible! Time to swap those out with something haha. Thanks for all the help along the way... I sure learned alot. Maybe next winter I will actually fix the pulsars... but maybe not! '78 CX500 - Back from the brink! '81 CX500C- Finally Running thanks to Ignitech!    Report

04-03-2010, 3:31 PM fll1441 Joined on 11-06-2006 Fort Lauderdale, FL Posts 976 Re: Got a 2nd CX, 81 CX500 Custom! Now I have to get it to RUN There's no such thing as a "cheater's fix." Good work getting her running. As for the custom handlebars, try rotating the bar down a bit. When I got my bike, the previous owner had turned them up. From the first pictures, it looks like yours are also too high. Mine were very uncomfortable like that. After I turned them back down, I liked them a lot. The factory position is indicated with two punch marks on the bar. The punch marks line up with the split in the clamp case. 1982 CX500 Custom    Report

Honda CX500 & G... » CX500 GL500 Tra... » General Discuss... » Got a 2nd CX, 81 CX500 Custom! Now I have to get it to RUN

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