vape/power dynamo finally going tits up?

[m in sc]

Ive had my ignition on my bike since.. 2007. so, its an OLD unit and has never given me issues. I do have an uptated 'ramped' rotor, and a zeel.

on the last 2 occasions ive ridden the bike, it would just cut off and provide no spark about 15-20 mins into a ride, usually under hard acceleration. BAM, like hitting the kill switch I -thought- it was a loose fuse, but nope. however, after it cools down, its seems to be fine. I even bypassed the zeel to limp it home and that didnt do it, so, its not wiring or the zeel box. anybody had one go out on them like this? im assuming either the coil or pickup is suspect since i took everything else out of the system and it still did it. 

thoughts?

[soonerbillz]

I've no experience bit have read a lot on the system.
Maybe this thread will be of assistance.

https://www.triumphrat.net/threads/vape-advise.971852/

[m in sc]

not really but thanks. Ive installed probably 10 of these but this very well might be the oldest one in the us, anmd th eonly one ive ever had an issue with , but being that old, im not really even mad about it.

Im also wondering if the new tach/speedo was causing an issue. Im going to bypass that for now and see if that cures it.

[irk_miller]

Double check that it's not a feedback issue.  How old are your plug wires and stuff like that?  Also check for under or over voltage and double check your grounds. 

[1976RD400C]

Shut down relay dropping out? If not, it must be one of the 2 coils.

[Striker1423]

the problem with the stator being where it is, the legs of it are hard to get to to measure. But, an old trick my  buddy taught me was each leg should kick out enough AC to power a standard 60w lightbulb. He went around a running bike and checked. Two legs lit the bulb bright as it should, while the third leg didn't light the bulb at all.... Bad stator.

This issue happened a lot in snowmobiles. Even stock sleds, if you ran the stock grip heaters, on high, with a heated shield, etc. It would burn out the stator's. They just didn't like the load. But in this case, it honestly sounds like it just went from age.

[m in sc]

its nowhere near a stock wiring harness, but the relay is fine.   it literally just shuts down, no spark, then after it sits a bit fires right back up and runs again for another 10-15 mins.  It very well might be the coil. But, I'm going to disconnect the tach lead and see if that cures it. If the tach is holding voltage in it or back feeding, this would def cause an issue.

vape does sell a tach output module, which i ordered, to see if that cures it. I have a new pickup (not yet installed). after that, it can only be the coil. 

I needed to do some work to the bike anyway, so Im just going to go thru it all and go from there. But, as is said: always check the last thing you did, and that would be the tach. 

@ striker thats what im trying to determine as well. Might just be age issues

[gargantua350]

Maybe if you can check the primary side of the coil like attach a lead to meter when it cuts out?  That way, you can see if the signal into the coils is suspect. 

[m in sc]

Id love to, you're right. but i will need to replicate the condition in the shop. its only done this 2x but both times were on the road and was a royal PIA to get tot he wiring on the side of the road.  that mostly has to do with how the petcocks are done/routed, but I finrally got a solution for that (have been fighting that for over a decade.. sometimes i'm a slow learner).

I'm working on that now, like said i need to clean a few things up for easier access.


this is the basic wiring layout under the back of the tank. the fuse box is different now because these would get loose(pic from '18).

[m in sc]

Going to try a new coil after talking to John. figured if anyone has long term dealings with these, its him.

[scully]

could be the magneto coil going out when hot too.

[m in sc]

very possible. I hope not but if it is, it is.

[gargantua350]

sometimes its easier to troubleshoot by substitution.  You will figure it out.

[m in sc]

thats kind of how i feel about it. I'm currently running 3 of these, so even if i wind up with a spare coil, etc, its going to be fine by me.

[m in sc]

test this morning was: install new coil, run bike in shop until fan cycled. didn't make it, water temp got to 178 and bike just shut down after about 20 mins... which is what i experienced on the last 2 rides..

turned out to be the pickup. Old one: 190+ ohm resistance, new one: 82.

it appears the older ones were higher rated (see link) https://www.powerdynamo.biz/eng/kb/values.htm
and as stated it was 15 years old. coil tested ok.


took pickup off, tested it, and read high compared to new one. swapped pickup (had new one on hand, thanks John), reset static timing with the zeel, and ran it to where it heat cycled the fan 2 times (fan kicks on at head temp of 207) and stayed running. I literally ran it for an hour in the shop it never gets that heat soaked, so, I'll call it fixed. will take out on testride later but it never sees temps that high on the road.