Yanmar 1 gm10 Flywheel - Advice needed please

[Appledore]

Like many Yanmar 1 gm 10's, mine is difficult to start with the button, and I usually end up using the decompressor and dropping the lever when the engine is turning over.

This week I removed the starter motor with a view to buying a new one. The bendix is very dry, with rusty dust around it, and inside the casing (when it is tapped rusty 'dust' drops out), and the shaft is quite pitted. It's almost as if it's been submerged in water, but I doubt it has or the thing wouldn't work at all.

The flywheel itself is rust-coloured, but it's not rusty if that makes sense, and is dry and free from oil, etc. My real concern is that when I replace the starter motor, the bendix will (should) be greased, and the rusty dust from the flywheel could cause even more problems at some time.

I've read that the flywheel itself should not be greased or oiled for obvious reasons, but what can I do to suppress the rusty dust? I thought of spraying it with WD40 or the like, just to leave a coating on it, but what do you guys think?

Thanks for your valued replies.

Geoff

 

[pampas]

DO not grease the bendix as this will allow dirt to accumulate and jam, a few drops of oil will solve the problem. or a spray of Gt85 (Teflon)spray, also good for polishing most surfaces and a pleasent smell, obtainable from most motor factors

 

[Bosun Higgs]

Like many Yanmar 1 gm 10's, mine is difficult to start with the button, and I usually end up using the decompressor and dropping the lever when the engine is turning over.

Really? Mine was only ever like that once and that was down to the tappets needing adjustment and the valves never closing properly. Unless of course your engine is really old and well worn.

This week I removed the starter motor with a view to buying a new one. The bendix is very dry, with rusty dust around it, and inside the casing (when it is tapped rusty 'dust' drops out), and the shaft is quite pitted. It's almost as if it's been submerged in water, but I doubt it has or the thing wouldn't work at all.

The flywheel itself is rust-coloured, but it's not rusty if that makes sense, and is dry and free from oil, etc. My real concern is that when I replace the starter motor, the bendix will (should) be greased, and the rusty dust from the flywheel could cause even more problems at some time.

I've read that the flywheel itself should not be greased or oiled for obvious reasons, but what can I do to suppress the rusty dust? I thought of spraying it with WD40 or the like, just to leave a coating on it, but what do you guys think?

Thanks for your valued replies.

Geoff

Surface rust on the flywheel is to be expected - bare steel and moist atmosphere. But pitting is not. There must be some water getting in somewhere, say from the shaft seal maybe? You need to have a good look round.

If you were bothered you could spray the flywheel with Duck oil from an aerosol ( good car spares place). Its a light wax and it will cut down on the rusting of bare steel whilst not being much of a lubricant. But I wouldnt worry. The gear of the starter motor should be clean and any rust that forms will rub off the next time you start the engine.

 

[Appledore]

Really? Mine was only ever like that once and that was down to the tappets needing adjustment and the valves never closing properly. Unless of course your engine is really old and well worn.

Sorry, not properly explained. When I turn the key and press the starter button, the starter seems not to engage the flywheel properly, and does not turn it. This is with 2 fully charged batteries! Decompressing the engine gets the starter engaged and the flywheel spins freely, as it should. It's nothing to do with the engine not starting, rather the starter motor not doing its job.

 

[Burnham Bob]

maybe you've already thought of this but if you're getting a new starter motor, buy from a motor factor not a yanmar agent or chandlery!

the price difference is amazing on bits like that

 

[Appledore]

maybe you've already thought of this but if you're getting a new starter motor, buy from a motor factor not a yanmar agent or chandlery!

the price difference is amazing on bits like that

Oh yes, yes!!! I've seen the prices, LOL

 

[pampas]

Further to my post. remove starter and take to an auto electrician and get it overhauled, probably a Hitaici starter. Will save a lot of dosh that way.

 

[Tranona]

Sorry, not properly explained. When I turn the key and press the starter button, the starter seems not to engage the flywheel properly, and does not turn it. This is with 2 fully charged batteries! Decompressing the engine gets the starter engaged and the flywheel spins freely, as it should. It's nothing to do with the engine not starting, rather the starter motor not doing its job.

The most common fault with Yanmars not turning over with fully charged batteries is connections. Remove and clean all the cables and pay particular attention to the contacts in the multipin connector in the main wiring loom. The starters are more than powerful enough provided they are getting adequate current. Still worth getting the starter motor checked by a specialist - there is usually one in any major town.