Overheated my 103 engine?

Hello All,

About 8 months ago, was the last time I rode my 103 and I had set it aside after it seemed to lose compression and over heat. It did not seize, but it was popping and sputtering and such and managed to limp home. The upper plastic part of my stock gurtner carb had a crack in it and it may have sucked air causing it to run lean. Anyhow, I have the engine out and plan to tear into it. However, i am unsure what to look for and what to buy. My motor may be an odball, its from a fixed rear suspension 103 which was sold in a lesser common version and for some reason (maybe price point) it is non variated. i don't believe it is a 102 engine, just a non variated 103 variant. So with that said, I am unsure if standard 103 parts will work. I am on the fence with finding a variated 103 engine and swapping it out or rebuilding what I have. To make the variated swap, I know I need to do a few frame mods.

If anyone has a stock engine lying around from an upgrade build, I would be interested. Also there is a 103 lower end on her for sale, but it has a 5 coil stator and mine is 2 and I am unsure if the wiring is compatible. Anyone know?

Any help would be appreciated,


Re: Overheated my 103 engine?

stock, these guys are hard to destroy, imho.

because it did not seize, tick off the following list of things to check / replace:

1. did you run out of gas. im not being a silly goose, appropriate gas flow helps a gurtner.

2. clean carb. that air filter crack could suck in particles and gunk that might clog small holes. or shit from the tank, but gurties have a tickler anyways.

3. spark plug - make sure it didn't suck in a grain of sand that got wedged in the spark plug gap. this can cause erratic misfiring and junk.

4. condenser/timing - get a new one. also get a micrometer timing tool or digital calipers and check/set the timing.

5. ditch the 2 coil for a 5 coil altogether, and put an external (or at least new ) condenser. the wiki prolly has some kind of information on this stuff, but try searching here or lmk if you need a good 5-coil diagram.

6. compression - test it with a tester! check ring condition, replace if necessary, check cylinder/piston for wear.

you should be able to do all this on the bench and get it back to life. the non variated ones have a shorter drive-side crank and maybe different cases (?) no clue.

if you are on the fence, give this lil pug a fighting chance ;)

please post a pic of the frame too if you can!

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