Mk3 starter gear/primary chain interference

I pulled the primary on my Mk3 this weekend to replace a leaky crank seal. When I re-installed the primary sprocket and starter drive gear, everything looked good until I put the alternator rotor on and torqued it. I noticed the starter drive gear was no longer moving freely and was in fact fouling the primary chain slightly. I pulled everything back off and everything appears to be in good shape with no apparent signs of wear.

I'm thinking I can put a shiim behind the thrust washer that lies inside the crank sprocket. This should push the starter gear needle bearing sleeve out slightly and the outer thrust washer should no longer bear on the starter gear.

Anyone ever experience this? Any idea on why this should be happening? Am I overlooking something?

It was moving freely before you disassembled? I just did mine, and it's the same. Soon as I put the antibackfire device and outrigger on I couldn't turn the gear by hand. I think that's how it's supposed to be?

Pull everything back off and start over, one bit at a time, making sure inside/outside orientation is correct on each bit as you go along.

Everything should be free and clear in it's area of operation.

I'm not intentionally trying to insult your intelligence, but you did definately put the outer washer (06-5761) into the drive sprocket (with the flat side going in first.) didn't you?

I would have thought that this installed correctly would give you the correct spacing of the sprocket and drive gear.Are you sure it's the chain it's fouling and not the sprocket face?

As grandpaul says, strip it and re-do it, if it was OK before, the question is, what has changed/altered?

Have a look at Old Britts " Pictorial help with installing the E-start starter gear train."

Solved! I knew it had to be something simple. It was...me. The primary chain had jumped one row over on the engine sprocket as I fed the alternator stator through it. I came home from work tonight and took one look at it and it was as obvious as the nose on my face. With the depth of the Mk3 engine sprocket, the chain lays neatly on it and I didn't look behind the chain at the row of empty teeth! Sometimes I amaze myself!

Pelican, I always pop the starter motor off so I can spin the gears to make sure the sprag is working properly. That's why they moved freely. The starter motor is the last thing on as I button up the primary.

I had everything but the crank sprocket off about 4 times yesterday. Sometimes you just have to walk away and come back for a fresh look.

Ron L said:

I always pop the starter motor off so I can spin the gears to make sure the sprag is working properly. That's why they moved freely. The starter motor is the last thing on as I button up the primary.

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oh ok, makes sense then

Ron L said:

Sometimes you just have to walk away and come back for a fresh look.

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This is true, glad it was something simple, and you got it worked out.