85 Quits running

[vpfly]

I have an 85 Vmax with pretty much stock. Last summer, it died on us when we were on the interstate. It was a really hot day. Luckily, we were able to coast up an off ramp and walk it to a gas station. After it cooled down for about an hour, it started up fine and we made it home without any problems. A few weeks later, it happened again and I put it in the shop. They found a problem with the charging system, changed the stator, R/R and put a new battery in it. It ran fine , but when it started getting cold, it would not start at all. It would just turn over, but not fire off. I used starting fluid and tried again, but it wouldn't start at all until it started getting warmer in the spring again. Then it started up fine. It's been running pretty good, but I had it out yesterday (it was HOT out) and again, it died on us out of the blue. After I let it cool off for about a half hour, it started up fine. I think I see a correlation between the temp gauge starting to get close to the red and the engine quitting, but it seems to be sporadic. If I'm sitting in traffic on a hot day, the engine temp starts to go up, but its never overheated. Voltage on the battery is strong all the time. I had a guy tell me the ignition coils are notorious for overheating and failing until they cooled...but, would they all 4 fail at the same time? I was also thinking it could be the TCI. I'm hoping some of the experts here could help me out.

Thanks!

 

[PATMAX]

Sounds exactly like my 90. Got so unreliable that I just parked it until I could trouble shoot it. It's not the coils but the the Pickup coil. An expensive part. Easy to replace though. I can't definitively rule out your CDI box but if it were my bike, I'd switch out the CDI borrowed from someone and then change out the pickup coil(s). They are a two pickup design on pre-90 bikes and four pick up design from there and newer if I recall correctly.
If you don 't have a local buddy to try their CDI, Sean will loan you one. Might as well order the
Pick up from him too! Good luck.

 

[wildweasel_pt]

Sounds exactly like my 90. Got so unreliable that I just parked it until I could trouble shoot it. It's not the coils but the the Pickup coil. An expensive part. Easy to replace though. I can't definitively rule out your CDI box but if it were my bike, I'd switch out the CDI borrowed from someone and then change out the pickup coil(s). They are a two pickup design on pre-90 bikes and four pick up design from there and newer if I recall correctly.
If you don 't have a local buddy to try their CDI, Sean will loan you one. Might as well order the
Pick up from him too! Good luck.

< '90 - 4 pickup
>= '90 - 1 pickup

 

[PATMAX]

Thanks Fred! You are a wealth of useful information!

 

[Fire-medic]

I recently had a pickup coil problem. In my (second) engine which blew after a dyno run, the p/u coil was fine, no issues. But then I used the original (first) engine taken out of the bike to replace the dyno casualty engine. The stock first engine had a bad 2nd gear, which was fixed along w/now having a good crank/rods which were the casualties of the dyno run in the 2nd engine I had bought to replace the bad 2nd gear in the original (first) engine. When the original repaired (first) engine went in, no starting though it turned over fine. No spark to the plugs. The CDI had worked fine w/the dyno casualty engine, prior to the rod failure, no reason to suspect it. Connections checked, all OK.

The problem turned out to be the original engine's pickup coil which had more than one spot where the oil-soaked insulation had deteriorated and apparently allowed a short. Replacing it w/the pickup coil from the dyno casualty engine did the trick. The engine barely turns-over & it's running, and I still have the ignition upgrade to do.

The location of the failed insulation on the p/u coil leads was under the sheet-metal wire cover next to the stator. There were also bad spots of insulation outside the case grommet which passes the electrical leads thru the side engine cover. I am trying to figure out if there is a way to repair the insulation for the leads, as I suspect that the p/u coil is good, and that it is just that the failed insulation let the thing short to ground. Since the grommet is bonded to the wires, it may be difficult to repair the insulation w/heat shrink tubing. I was thinking about maybe trying that liquid insulation, which hardens into a pliable coating after you paint it on, after using acetone or lacquer thinner to clean the wires and insulation of oil residue.

 

[vpfly]

Thanks to all you guys for responding.