#3 coil question again...

[1BigDog]

As most here know the bike has sat for a while and I got her running pretty good but the other week, coming home from work she started to pop and miss while climbing up a bridge (under load) and as I got closer to home the popping was more prevalent while at low speed. It was suggested to me that my carbs may need to be colortuned as I had the air/fuel mixture screws out and they may not be set right. Today I was able to get around to colortune it and while I had the bike warming up I took a wet cloth and dripped water onto each pipe. Every pipe except #3 sizzled. #3 the water just ran off. So, does that sound like a bad coil to you? I could touch the pipe and it felt warm.

 

Im thinking that after 14 years the coil may be bad after all. What are your thoughts on this before I order one?.

[V7Goose]

Contrary to what some people seem to think, the coils on these bikes RARELY go bad. If you truely have a spark problem, it is most likely just corrosion in the plug cap.

 

More likely problem is dirty pilot jet in the carb for that cylinder. Easy test for that is to pull the vacuum hose or cap off the vacuum port for that cylinder and spray a little starter fluid or carb cleaner in it while at idle - if the engine speed picks up, you have good spark.

 

Goose

[Guest]

Thanks for the response, Kent. Muffinman also suggested the carb issue a few weeks ago and I got a bit agitated this morning and walked away from the bike, forgetting about it. After posting I went back when I cooled off and checked the cylinder and there was a good spark at the plug. Glad I didnt pull the trigger on new coils. Since I cannot kneel anymore I have to get the bike up in the air again to see under the carbs for the adjustment screws. I have the tank off and I am using an aux tank for fuel. Ill give it another shot on Friday.

[Guest]

Pulled the trigger on #3 coil. Did all of the tests up to putting in 2 new spark plugs and the cylinder is still cold. Spark looked very weak and sporadic compared to the other cylinders. Adjusted the air/fuel mixture screw which eliminated the backfire but cyl was still cold. Tired of messing with it. Thought id take it out for a ride today but not the case.

 

Did one more thing tonight. Took apart the plug wire from the plug. The wires inside were pretty shot. Pieces of them coming apart. I clipped off about 1/2" and had a fresh core. I screwed the end back on, fired her up and, and, and...........still had a cold cylinder. Sigh.....

Edited July 11, 2013 by Ruffy