1978 Peugeot Misbehaving again

Chris Robertson /


This will be a typical, really long, Chris Robertson post... You've been warned.

My 1978 Peugeot has begun acting up again. There was a discussion about it in <a href=" https://www.mopedarmy.com/forums/discuss/1/38632/38632/">this thread</a> about a month ago.

The problem at the time was that after running it for fifteen minutes or so and getting the engine very hot, it would be impossible to start for fifteen minutes or so until (I presume) it had cooled off.

Since then the problem seemed to go away on its own.

Two weeks ago, this moped got stolen (and then found), but I don't think it was abused. When I got it back the thief had carefully cleaned and detailed the ped, and carefully taped the wiring so that it didn't look as messy --so I don't think any damage was incurred while the moped was in the thief's care (for about 48 hours). I mention this just for completeness' sake.

Yesterday I went on a trip to a hardware store on this moped. This trip is almost completely wide open throttle travelling. It was running perfectly (except for a little bit of sputtering towards the end) all the way there (about 5km / ~3 miles). When we got to the hardware store it was closed, so we turned around and started to head back. The moped was never shut off. About 1km later I lost all power. As I slowed from 50km/h (35mph) I tried everything I could think of to get the engine to sputter. I choked it, I toggled the ignition kill switch, I fiddled with the wiring. Nothing.

Assuming that this is a similar problem to the one I had before, I sat down at the edge of the road and waited fifteen minutes for the moped to cool off. The engine had cooled off quite a bit (I could put my hand on the exhaust), but wouldn't start. I took the magneto cover off and touched the flywheel. It was <i>extremely</i> hot. Hot enough that I could have burned my fingers if I hadn't touched it gingerly.

I began the walk of shame home. After about twenty minutes of walking (and at the top of a hill) I jumped on and managed to eventually get the thing to fire up. By this point the magneto had cooled off quite a bit. The moped ran perfectly well the rest of the way home.

Obviously I have a heat-related problem.

My questions:


<li>Is it normal for a magneto to get that hot? Could that be the problem?</li>

<li>Any ideas what else it could be? Any measurements I should take to help diagnose?</li>



Re: 1978 Peugeot Misbehaving again

david f martin /

The engine is probably the source of that heat, not the magneto.

Check the plug. Make sure you're getting enough oil.


Re: 1978 Peugeot Misbehaving again

Chris mine did and does teh same thing it comes and goes randomly I havn'et been able to figure it out either.. I use a pretty rich gas mixture too. I have never tried waiting.. I normaly park it when it starts acting up and ride it the next day as I do most of my driving in the evening. I'll have to try it letting it cool down too. Ps... My filter was worn out completly and almost non exsitant I got a new one and it doens't do it as badly... still does it though soemtimes... kinda sputter and like a momentary miss or lose of power for like 1 stroke it seems... like if you hit your kill switch in mid throtal then flipped it back on a few tiems in a row...

Re: 1978 Peugeot Misbehaving new observation


I tried the same errand again with the same moped today. Temperature and wind were about the same as yesterday. What was different was that I left the magneto cover off this time.

I made it to the store and the magneto was not very hot at all. I could put my finger on the flywheel for ten seconds. This is in sharp contrast to yesterday where I could have burned myself in under a second.

The moped was a little tricky to start when I left the store, but it did start and ran perfectly all the way home. When I got home the magneto, again, was not very hot.

Maybe the magneto cover doesn't allow enough ventilation?


Re: 1978 Peugeot Misbehaving new observation

I am thinking the same thing might be up with mine.. most times i drove it after working on it it drove fine... and those times would have been before i put on the mag cover and the plasitc panels.... normaly after I confirmed it running good i would put the stuff on the next day or two and run it and it seems like thats when my problems would act up..

I would take everything apart brush the points with sndpaper a time or two and adjust the carb ride it and it would be fine... put it back together and the cycle would stat agian.. i never really put two and two together until you started describing your problems..

looks like we have aobu tthe same thing going on.

I'm wondering if I drill a few holes int he mag cover and see if it helps any I', also going to try and make a mini scoop o vent and add it to my plastic cover to get a little more air circulating around in there. I park my moped under a lean too so im not to worried about the magneto geting wet due to wearthr.. and i don't drive mine as trasportation so i dont think ill be driving int he rain much.

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