Started fine - but second go, not first. Why?

[NPMR]

Yanmar 1GM10. Switched on, pressed starter button, starter turned, engine turned a bit and then stopped dead.

Released starter button and tried again. Starter turned, engine turned, engine started. Any thoughts as to why the difference? What to look for?

This happened a few times last year and this was the first time this year (after launching). Battery tested OK during the winter.

 

[VicS]

Dirty contacts some where. Solenoid maybe. Starter button maybe. really need to investigate to find out if power is getting to the solenoid coil when the button is pressed. If not find out why not. If it is then is the solenoid operating mecanically , if it is then its contacts are dirty, or there is a bad connection on battery or solenoid

But have all main connections been cleaned and checked. Do not overlook the negative from battery to engine.

 

[oilyrag]

Could be electrical, the Yanmar start buttons in particular are [--word removed--] and worth checking, but symptoms would also suggest hydraulic lock. This is due to the old chestnut of not checking the exhaust elbow, which, when the inner perforates, allows water into the combustion chamber. If you haven't checked or renewed yours lately then it's a very good idea to check it regardless.

 

[NPMR]

I hope it's not the exhaust - as I change that every two years because it is so porous and such rubbish! (Did you know that Barrus - the importer - reduced the price of this thing to about £65 the same cost as the USA price? The re-sellers don't seem to either a) know, or b) want to pass on the reduction to end-users!)

Why does the engine turn over well with the second push of the button (If it's not the hydraulic situation above?) Is it just cleaning the contact on the first push?

 

[oilyrag]

If the elbow is recent then unlikely to be the cause and VicS is probably right about a poor connection somewhere. Worth checking the start button as mine had actually disintegrated. If it's suspect you can get a replacement from a Truck factor for less than a tenner rather than pay Yanmar prices.

 

[steve28]

the inline fuse in the engine wiring harness can cause problems. found near the gear change cable where it attaches to the engine.

 

[Slinky Spring]

Is it possible to buy direct from Barrus at that price. Just about to shell out the £110 currently being asked by the dealer so it would be nice to know.
I have tried all winter to find someone who will make me a copy in stainless without any success.