Join Date: Aug 2006
Location: Prairie Grove, IL (suburban chicago)
Wierd intermittant syndrome
Hi VN750 forums:
I'm a new member and I was referred to this forum to see if anyone had experience with this problem. I'll try to briefly explain, but like most electrical problems, it takes some explaining.
My 86 VN 750 would fire up and run fine for about 30 sec. then rear cylinder would not fire. It is not fuel related, i checked the spark and when it fires it gets a strong blue spark. After running on one cyl for a few miles it would usually suddenly kick back in (sometimes very exciting) and run on both for the duration of the ride. As I tried to diagnose, I lived with this pattern, but now cyl #2 does not come to life after warming up. To see if the coil was the problem I reversed the front and rear coil to see if the problem migrated to the other cylinder. It didn't - but remained on the rear cyl.
I finally determined that the rear pick up coil is defective and bought a new set of pick up coils, which I started to install last night. My Haynes manual said that I could change pickup coils by removing the outer alternator cover and tracing the wires back to the harness. Unfortunately, the shop manual says the first step is to remove the engine. Yikes. I took off the outer alt cover and sure enough, there was all the access I needed to replace the pick ups, but the wire runs through a slot in the inner alt cover and it is partially blocked by the frame, so it appears that the shop manual is correct. My question is, has anyone replaced these and do you know a shortcut to get that wire through the slot (maybe loosen the inside alt bolts to squeeze the wires through?). I am a willing but overall untallented mechanic. Also short on $ so I don't want to pay the local shop to do the job.
By the way, I have replaced the spark plug wires, battery and cleaned the terminals. When the #2 cylinder kicked in the bike ran great. Any suggestions?