volvo

[kujawski]

Can anyone help please,

I have a volvo b30 engine with 3 solex carbs,
its on a boat engine setup is what used to be called an AQ170,

anyway, it starts fine, revs etc no problem, but when the engine is left running for 1/2 hr plus(ie after its warmed up) and then stopped, and left for 10 mins plus, it just wont start,. starts from cold no problem,.
any idea what could be causing it, put petrol in tank, checked plugs and spark all appear fine, (else it wouldnt start) , only when warm then it just wont kick in unless the started motor is left running for 30 secs (at least) then it eventually kicks in.

any idea anyone as its doing my head in.

[Toureman]

It's a long shot but does it have a mechanical petrol pump? When you switch an engine off it does get hotter as the coolant is not being circulated, this sometimes causes the petrol to heat up and the petrol in the pump vaporizes and causes an airlock in the pump.

[kujawski]

yep, it has got a mechanical petrol pump,
it is raw water cooled, ie straight from the river,so it may be the case, but when i pump the throttle petrol is still being pumped into the carbs?

thanks anyway,