A Successful Repair Story

Recently bought a 1980 Peugeot TSM-U that had been sitting in storage for six years, but just prior was kitted with some fresh goods:


Ported 70cc Gilardoni w/ 49cm Peugeot head

Dellorto PGHB carb

Malossi Multivar

Ninja G3 Pipe

I basically put a fresh bulb in the headlight, air in the tires, gas in the tank, and with a lot of kicking and pedaling got it to fire up. It ran GREAT. Totally ripped. Every time I went to start it after that it was a snap. On its first cross-town ride (5ish miles) it got me all the way there. Then, it sat for about an hour, and refused to start. I had to haul it home and started going down the check list provided by Fred's guide and Myron's mopeds.

Digging in, I learned it had just OK compression, so replaced an old base gasket with a custom CNC machined gasket. Compression was now solid. Took apart the carb and cleaned it thoroughly, so gas flow was very good. I had spark, but it was a bit weak. I didn't think it was so weak that it would be the root cause, and it also didn't make sense to me that this would all of a sudden be the issue. I ignored addressing the spark for about a week, pedaling my ass off trying to get the bike to start. Got lucky once but otherwise couldn't replicate.

Then I pulled the flywheel off and discovered the magneto wiring was being chaffed through by the edge of the flywheel!


The white wire was almost completely severed, clinging to itself by two strands. Reattached that sucker and wound it with some heavy rubber and electrical tape to keep that from happening again. Spark was now definitely stronger.

Reset timing to 1.4mm BTDC (was previously in that same ballpark) and tried to start the bike—still no luck.

Then I checked plug gap and set at .4mm, and checked and set the point gap to .4mm (was previously .3mm, and points were already clean).

THE TSM NOW STARTS ITSELF. Like Cheetahchrome's 103, the bike is a runaway.

Time to dive into tuning!

Re: A Successful Repair Story

very well, now why did the wire chaffe there? did the rubber isolater cut itself in half leaving the wire exposed to the spinning magneto?

Re: A Successful Repair Story

> pat splat Wrote:

> -------------------------------------------------------

> very well, now why did the wire chaffe there? did the rubber isolater

> cut itself in half leaving the wire exposed to the spinning magneto?

Someone moving, pushing or pulling on the harness during maintenance or repair. It can happen on Garelli NOI too. Ask me how I know. (edited)

Re: A Successful Repair Story

Andy Nielsen /

After riding yesterday and today, the flywheel continues to chew through the magneto wiring! Looks like I'll need to find a better way to tack down the wiring harness to keep it out of the way. The rubber mount slips in and out very easily, so it probably jiggles itself into harm's way as I ride. Taking suggestions as to how to keep it in place, but might just try super glue.

Re: A Successful Repair Story

Clean the rubber and where it mounts with rubbing alcohol or the like .

Apply a bit of silicone gasket maker around the mating edge , but not on the cover edge .

Install and let cure , fully .

Re: A Successful Repair Story

maybe just deepen the groove with a dremel so it sits farther back and glue in place, actually super glue has ridiculous grab strength between rubber and metal.

Re: A Successful Repair Story

Are you running it with the cover in place? The cover will keep it pushed down and out of harms way.

Re: A Successful Repair Story

This is very common on the 5 coil if you don’t use a flywheel cover. I cut out the back of the mounting plate so the wires can go out the back instead of down through the bottom.

Re: A Successful Repair Story

Andy Nielsen /

Super glue has worked great so far, but I think silicon gasket maker will be a better long term fix without dremeling away the mounting plate. I don't have a flywheel cover but might end up nabbing one after I tack down timing that I like. Thanks all for the recs!

Re: A Successful Repair Story

When I do use super glue, I use it as a last resort because it breaks down over time with exposure to moisture and humidity.

Re: A Successful Repair Story

Andy Nielsen /

Silicon gasket maker FTW. Super glue definitely fell apart.

Applied the silicone once and holding strong!

Thanks all.

Re: A Successful Repair Story

roots to wings /

cool lookin ride

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