essman Posted April 20, 2009 Share Posted April 20, 2009 This weekend I was doing some lighting upgrades on my 2002 R1150RT-P and I let the battery run down. When I hooked up the trickle charge, that wasn't working. So, I hooked another 12v battery in to the power plug and let it sit overnight. This morning it started, but it is running only on the left cylinder. There seems to be fuel supplied since the right cylinder plug gets wet when cranking. I got a pretty good jolt when I was checking for spark. It looks good like a good spark--hard to tell if it looks a strong as the left side. Any thoughts out there? Link to comment
T__ Posted April 20, 2009 Share Posted April 20, 2009 essman, well if you have spark & fuel & compression it should run on that cylinder.. Maybe try a new spark plug just to se if that is the problem.. Just because you got a jolt doesn’t mean you have enough spark (takes way more than that).. Pop a good plug in the wire, lay it on the cyl head,, then crank it,, you should see a bluish spark jump the electrode gap with a good snap.. Any chance you knocked the throttle cable loose at the TBI cable bushing? (check it to be sure).. That is a very easy to do & will render that cylinder pretty dead. Twisty Link to comment
essman Posted April 20, 2009 Author Share Posted April 20, 2009 Yes, I tried another spark plug and I did check the throttle cable connection to the throttle body since I've done that before Link to comment
T__ Posted April 20, 2009 Share Posted April 20, 2009 essman, I guess the next place to go is check the spark (blue spark) & cranking compression.. Twisty Link to comment
essman Posted April 20, 2009 Author Share Posted April 20, 2009 If the spark is weak, would that indicate a weak coil? It wouldn't seem like running the battery down and trying to crank it with a low battery would have damaged anything, but maybe something was weak and about to go. When everything is working fine until I mess with it, I tend to look for something that I have done, though coincidences do happen also. While I had the tupperware off, I pulled out some of the old wiring from the police accessories, but it doesn't seem like, if that were it, it would only affect only one side. Link to comment
T__ Posted April 20, 2009 Share Posted April 20, 2009 Essman, the same coil fires both spark plugs so unless the coil became damaged on the dead cylinder side it probably isn’t the coil.. It is possible the plug wire on the bad side got damaged or partially disconnected (do the spark across the good plug test).. You need to see a bluish colored snappy spark or you have spark issues on that side (probably the plug wire).. Those RTP plug wires are shielded so it is difficult to see if they are arcing inside the shielding.. They aren’t cheap to replace either.. Go back over what you removed to see if you pulled something loose at the fuel injector or tugged on the spark plug wire.. Twisty Link to comment
Dave in Doodah Posted April 20, 2009 Share Posted April 20, 2009 No hi-jack intended, but I know on my old R100 you need to be careful when checking for spark, or when cranking the starter with plugs pulled but attached. This was supposed to wreck havoc on the transistorized ignition unless you took care to ground the plug base to the cylinder. Can i assume this is still something one needs to be careful about on the oilheads? Thanks - just making sure, in case some folks did not know, or if I was worried about nothing. Link to comment
T__ Posted April 20, 2009 Share Posted April 20, 2009 Dave, it won’t hurt the transistorized ignition.. In fact if the plugs are properly grounded to the metal on the engine the system won’t even know the plugs are not in their holes.. If it is cranked long enough with just the wire dangling in space & not grounded across the spark plug gap it can cause internal coil damage from internal arcing but that would take a lot of cranking to harm anything.. Twisty Link to comment
essman Posted April 21, 2009 Author Share Posted April 21, 2009 Today, I pulled the tank and looked around for wires and cables that might have gotten yanked. I held the plug wire away from the frame and moved it around to see if it was arcing somewhere--Nothing. Maybe it is the spark. When I run the engine with the right plug grounded to the head (spare plug in the cylinder)the spark does not look blue and snappy, it randomly alternates from one of the two electrodes to the other and is sort of blue, but also yellow. But, when I do this to the good side, of course the engine is not running but only cranking from the starter) it looks the same. Is it possible to have a weak coil that only has enough juice for one cylinder? It sure starts up easily on that one cylinder. Link to comment
T__ Posted April 21, 2009 Share Posted April 21, 2009 essman, no,, if the coil has enough oomph to spark one side correctly it has enough for the other side as the coil secondary is a continuous loop from one plug to the other.. Now that doesn’t mean the spark isn’t getting sapped off to ground somewhere before it reaches the spark plug.. Can you get the plug wire from the good side over to the bad side? If so try that to see if it will then run on the other side.. Take an old spark plug & open the electrode gap to 3/16” (use a 3/16” drill bit as a gap gauge).. Pop that in there,, lay on cyl head & see if you get a spark across that extended gap.. If so you have enough spark to run that cylinder.. If the spark looks similar on each side it should at least try to run on the bad side.. Do you have decent compression on the bad side? Is the fuel injector squirting fuel on the bad side? (pull the injector out with it still hooked to the wire & fuel line,, point it into a small jar & crank the engine).. If you are getting good fuel over there you should see a good series of squirts.. Go back over the throttle cables again.. They should BOTH hit the closed stop at the EXACT time.. Added: maybe the throttle cable is pulled out of the seat at the junction box.. Cycle the throttle & feel for BOTH sides opening & hitting wide open the same time & both sides hitting closed throttle stops at the same time.. Twisty Link to comment
essman Posted April 21, 2009 Author Share Posted April 21, 2009 So---I did think to try switching wires---however--on one side the cable comes off, on the other side the holding nut just spins as the threaded part which is pressed into the coil housing just spins. To tight of a space to get a Vicegrip on---right now it is soaking in Kroil. I'll check the throttle cables again, and checking the injector spray and wide gapping are good ideas. It'll keep me busy, anyway, while things soak--Thanks---Mark Link to comment
essman Posted April 21, 2009 Author Share Posted April 21, 2009 Update---the throttles definitely weren't hitting the stops at the same time--way off. In running wires, I may have pulled it slightly out of it's seat. It looked like it was in the seat, but I had to push it to get it down all the way. Can't work on it now, but I'll let you know how it turns out---Thanks Twisty Link to comment
BFish Posted April 21, 2009 Share Posted April 21, 2009 it should be much better, but the idle may be off some. DAMHIKT Link to comment
essman Posted April 21, 2009 Author Share Posted April 21, 2009 Twisty---you're the man--problem solved. When I was doing things, I appartntly pulled the left throttle cable out, not all the way so that it looked like it was out, but enough. It was a little tight in the seat and didn't go all the way back in without a push. I threw the coil and tank back on, fired her up, and she purrrs again---Thanks a heap Link to comment
T__ Posted April 21, 2009 Share Posted April 21, 2009 essman, good news.. I was beginning to wonder as you supposedly had spark, fuel,, & air.. It should have run OK.. Sometimes the simple things can drive a person crazy.. I’ll bet you NEVER have that problem again.. Be the first thing you check next time.. Twisty Link to comment
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