1978 Peugeot 103 woes

Howdy:

I've a 1978 Peugeot 103 that doesn't seem to want to run anymore.

It ran fine last summer, but when I took it out last weekend I couldn't get it to run properly. After several hours of fiddling with it I can get it to barely run (i.e. it'll fire and spin, but eventually die if I don't keep pedalling) --it will not run fast and it certainly won't idle with or without the choke. It fouls plugs with thick black carbon in seconds (i.e. 20 seconds of pseudo-running).

Here are the Peugeot's vital stat's:

1) The timing is dead-on with respect to the points (1.9mm before TDC). I've also tried retarding and advancing the timing from spec with no improvement.

2) Compression is 150psi.

3) I've decarbonized the cylinger, piston, exhaust, and ports.

4) I've cleaned the carb thoroughly, twice.

5) I've disconnected the wiring harness from the engine in case the problem is a short somewhere --the engine runs the same.

6) I wanted to remove the flywheel to adjust the stator advance, but I do not have the proper tool to do so. Since the moped used to run perfectly last year, I assume that the stator advance is probably fine.

7) I've cleaned the points as best I can.

8) The fuel mix is 50:1 as per manufacturer's specs.

9) The air filter and air box is clean.

I've all but run out of things that I can think of!

Can anyone out there suggest anything I should test/measure/try to get this engine running? If I need to split the crankcase or pull the flywheel, can someone suggest a place to get the special tools for this?

Thanks in advance,

Chris.

Re: 1978 Peugeot 103 woes

Puegeots are wierd... trust me.. mines been doing alomst the same thing for about 2 weeks now... :(

all I did was transfer everything from one bike to a new frame.

It ran jam up.. but mine now only is running witht he choke all the way pulled when i come to a stop.. the other times it is fine.. I dunno.

Re: 1978 Peugeot 103 woes

Oh and I went from 1/4 turn or a good kick to start to pedaling my ass off and getting lucky

Re: 1978 Peugeot 103 woes

Chris; the timing is 1.5mm .i would recheck the carb cleaning. these carbs have to be real clean. also the manifold has a reed in it that might not working right.

air leak at the manifold gasket

check and C if your getting a good flow of gas to the carb.

check for air leaks. Dan

Re: 1978 Peugeot 103 woes

Ron Brown /

>--it will not run fast and it certainly won't idle with or without >the choke. It fouls plugs with thick black carbon in seconds >(i.e. 20 seconds of pseudo-running).

Chris,

This has all the symptoms of a plugged main jet. Take it out again and look at it with a bright light and a magnifier.

Ron

Re: 1978 Peugeot 103 woes

Hi:

I spent a few more hours working on the moped today.

I cleaned the carburetor again <i>extremely</i> thoroughly.

I wanted to pull the flywheel but I don't have the proper tool. Out of desperation I drilled and tapped M8X1.0 holes in the flywheel and used a harmonic balance puller to try and pull the wheel off. After tightening for a while the bolts I threaded into the flywheel pulled out (destroying the fresh threads I had put in).

I retapped the flywheel with larger bolts (M10X1.5 this time). I hit the crank shaft with Liquid Wrench. I tightened the puller as far as I could. I banged on the flywheel with a hammer, I took a blow torch to the flywheel's center in a hope that that would loosen it. I put a length of pipe over the handle of my socket wrench and I tightened the puller some more until, finally, <b>the puller's tempered steel threads broke!</b>

And in case someone is about to ask, yes, I removed the flywheel nut!

Although I would still like to remove the flywheel and snoop around inside the magneto, I'm going to have to assume that the flywheel did <i>not</i> accidentally move out of spec.

I cleaned the exhaust again with a blowtorch --it's clean.

I put everything back together and the engine started and slowly picked up speed until it was running full bore. I kept this up for about twenty-five seconds and then slowed the engine down by letting up on the throttle. As the engine got to its mid-range I opened the throttle again to no avail. The engine eventually sputtered and died. After that the engine ran exactly as it had yesterday --it want to run, it fires, but won't go on its own. It no longer seems to be fouling plugs as ferociously as it used to.

Tomorrow I will swap carburetors with my other Peugeot and see what happens.

Can anyone tell me how to:

1) Remove the frikkin' flywheel from a Peugeot; and

2) Suggest what else might be wrong with this evil machine.

Thank you, and sorry for such a long post!

Chris.

Re: 1978 Peugeot 103 woes

Chris Robertson /

I've swapped carburetors with my other, working 1978 Peugeot 103. The problem is <i>definitely</i> not the carburetor (the working moped continued to work, the sick moped was still sick in exactly the same way).

The Peugeot no longer seems to be fouling plugs (in fact they are coming out looking okay).

I can start my moped and get it to run quite well at full bore, and even into the mid range. If I let it slow down too much it dies. When it is running it seems to miss a bit. It's also hard to start.

About the only thing I can think of is the magneto, but as I've mentioned I can't get the damned flywheel off.

Does anyone know where to get the special Peugeot flywheel puller?

I'm losing my mind!

Chris.

Success!

Chris Robertson /

Hi:

After fiddling for four whole days with this moped I finally got it running again.

I never did get the flywheel off, but I inspected every single wire in the wiring harness and I found some suspect connections which I repaired.

I'm a little confused as to why the wiring harness problems mattered since I had disconnected the engine from the harness completely and it still ran (or nearly ran).

I also have no idea why it was fouling plugs severely and then just started burning clean again.

Oh well, the moped now runs correctly.

Thanks Duck, Dan, and Ron for your input.

Chris.

Re: Success!

Carb might have a differ size jet in.I would get to the timing.

a puller runs about $20 if you find one. Chris at mopedwarehouse sent me one to use,he said he was out of them for sale. So i made one and it works slick as shit.Made the job so easy. Where you at maybe i can find one.

Made mine out of a peice of pipe. Treaded 1 end ,welded a nut on the other. and a bolt. Dan

Image07.jpg

Re: Success!

Chris Robertson /

Hi Dan:

I'm in Ottawa, Ontario, Canada.

I considered making my own flywheel puller. The diameter looks to be about 14mm. What size die did you use?

I wish I had a welding rig... But I can probably borrow one.

Did pulling your flywheel take an incredible amount of effort? I'm serious when I say I couldn't tighten my balance puller any tighter with my 8" socket wrench (I had to put a pipe over the end of it) before the balance puller finally broke.

Judging by my service manual, my timing is definitely out of spec (1.5mm BTDC is about 10-20 degrees after the rubber grommet is).

Thanks,

Chris.

removing the flywheel

Jon Dalton /

This method has never failed for me, it's even worked where I've broken the puller. You can take a coat hanger, bend small hooks on either end with pliers, bend the entire thing in half, and hook each end of it in either the holes in the flywheel if there are any, or the edge of it if there is a big enough space between it and the engine case. Now, support the moped with one foot and pull on the coat hanger while hitting the crankshaft end with a hammer. It's best to keep the nut on, but so that it's flush with the end of the crankshaft, to avoid mangling the threads. I used this on a Torrot engine, which I'm told is the same as a 103, with the same symptoms you're describing. Adjusting the stator plate did nothing for me. I'm pretty sure in my engine and possibly yours that it needs NEW points and condensor. There were a few engines that I fooled with engines for hours, thinking the points and condenser are fine because I cleaned them, but the new points were what they really needed.

removing the flywheel

Jon Dalton /

This method has never failed for me, it's even worked where I've broken the puller. You can take a coat hanger, bend small hooks on either end with pliers, bend the entire thing in half, and hook each end of it in either the holes in the flywheel if there are any, or the edge of it if there is a big enough space between it and the engine case. Now, support the moped with one foot and pull on the coat hanger while hitting the crankshaft end with a hammer. It's best to keep the nut on, but so that it's flush with the end of the crankshaft, to avoid mangling the threads. I used this on a Torrot engine, which I'm told is the same as a 103, with the same symptoms you're describing. Adjusting the stator plate did nothing for me. I'm pretty sure in my engine and possibly yours that it needs NEW points and condensor. There were a few engines that I fooled with for hours, thinking the points and condenser are fine because I cleaned them, but the new points were what they really needed.

Re: removing the flywheel

Chris Robertson /

Hi Jon:

Thanks for the advice.

I'm not sure that a coat hanger will be strong enough since I managed to destroy a balance puller trying to pop that wretched flywheel off, but I'll try it out anyway.

Thanks again!

Chris.

Re: removing the flywheel

Jon Dalton /

It's not the hanger that needs to be strong, all it does is provides some inertia while the hammer delivers the impact. The puller can only put a steady force on it, there's no dynamics involved. If this doesn't work at first, you can try putting a brick or something heavy in the coat hanger to give it more inertia - this just means that the flywheel has added weight so it would rather not move with the crankshaft when you hit it. This will deliver a lot of force to the flywheel / shaft joint but it's all based on the principle of impulse and momentum, and it doesn't create as much force in the coat hanger as a puller would on itself. I bent the puller arm made out of 1/8" by 1" steel trying to get the flywheel off, and then got it off with the 1/16" coat hanger and the hammer. It's the same principle that makes it easy to get wheel nuts off of a car with an impact gun you can hold in your hands easily while you would have to jump on the end of a wheel wrench to get the same nuts off.

Re: removing the flywheel

Chris Robertson /

Hi Jon:

Sounds interesting. I will definitely give it a try tonight.

To make sure I have this straight:

1) I attach a coathanger to the flywheel and put a moderate amount of tension on it (i.e. pull on it with my hand), while I

2) Bang the crankshaft that the flywheel is attached to with a hammer?

I'll give it a try...

Chris.

Re: Success!

Jon Dalton /

In my experience with pullers, if you need to put a pipe over it then you are at the point where the puller is going to break.

The flywheel shouldn't be this hard to get off. They are supposed to be held on snugly by the tapered fit to ensure that they are centered and won't wobble or come loose, but that is only frictional force of the two pieces being wedged together as the flywheel expands and the crankshaft compresses.

The problem with yours is that cold welding has happened at the molecular level between the aluminum flywheel and the steel crankshaft. Since they are both finely machined and pushed very close together, the steel atoms directly contact the aluminum atoms in enough places to set up metallic bonding, so in fact in a whole bunch of tiny little spaces, the crankshaft and the flywheel act like one piece of metal. Of course everyone knows you can't weld steel to aluminum, I just mean at tiny little points on the molecular level, they could never actually weld themselves together. This happens a lot with aluminum car rims on steel hubs. If you ever get it off, a light coat of anti-seize compound or oil or grease will prevent it from getting this way again.

Using a torch will work, as the flywheel is going to expand more than the shaft when heated, and greatly reduce the force needed to get the flywheel off. Just be really careful of the magneto coils inside. If you keep the torch aimed at the centre of the flywheel, and don't heat for too long, you should be ok. Don't give up if it doesn't work the first few times, keep trying and it should come off.

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