Problem with a boat engine

air leak on the inlet would be a good place to start looking, flooding is obvious on inspection.

Can you give us alot more info please. What marinised engines are they, what carb's do they have, what maintanance work has been carried out, has it always been tricky to start etc??

I am very surprised there are no chokes..

On the face of it, it sounds like a proper stage 0 tune is what they both want for starters!

Tim..

You would be able to smell the flooding, especially in an enclosed space, so I don't think its that - also a few cranks over at full throttle would clear it.

More likely is that the mixture is just too weak to fire a cold engine, so you need to be looking at why they lack a choke. Could they be automatic chokes and one works whilst the other doesn't on the engine which has starting problems?

There just has to be some way to enrich the mixture for purposes of cold starting.

if the carbs have throttle pumps, that will do the job. I have run several vehicles with no choke in the past, a few stabs on the throttle get them going (provided there is an accel. pump).

volvo car engines usually had vacuum type carbs with no throttle operated pump which is why it needs more info. to make anyyhing other than wild guesses.

Personally and from experience I would be quite frightened of a boat with inboard petrol engines, especially old ones with carburettors and no planned maintenance. In fact I would not use it at all, years ago I probably would have, now I value life and limb too much.

Mrcheerful

On 2008-02-09, Mrcheerful wrote: [...]

I had a Mk I Fiesta for a short time which seemed to have an accelerator pump and also what looked like a little "shelf" in the inlet manifold, or perhaps it was the throttle body, which would fill up with a little pool of petrol if you overdid it, thus preventing engine flooding.

The engines are marketed as marine engine, type AQ151 which may be marine versions of a car engine but I don't know which one. Before I bought it early last year, it had had the inlet manifolds removed and repaired by welding; it is common on these engines for corrosion to occur between the head and the inlet manifold, but this should have been sorted out. Also, I had the impression from the previous owners that this engine had always been more reluctant to start than the other.

Interestingly, the engine doesn't stink of petrol. I should be going down there tomorrow so I'l have a look for any ID marks on the carb.

You mentioned about a stage 0 tune, perhaps jokingly. If this was my car I'd probably have considered it and a '"home tune" isn't common in the boating world. Maybe you're on to something here :-)

Thanks

Neil

From my limited knowledge of what Volvo marinised as far as smallish 4 cylinder petrol motors, I would suggest you may have a B16, B18, B20 type(OHV, upright cast iron block and head) or a B200, B230 type (slant 4, OHC, crossflow, iron block, alloy head)

yes- i.e. fluids, valve clearances, new plugs, leads, dizzy cap, rotor arm, timing set up, carbs cleaned and properly set up etc.

Tim..

afaics they are the volvo penta engine giving 146hp with a solex carb. clymer do a manual for them (apparently)

Ah!

Abit of googling suggests that the AQ151 is a B230 red block with a stroked forged crank giving 2.5litres displacement, and it's fitted with twin carbs, a 531 head, V cam and has a 10:1 CR.

Twin what carbs I cant discover, but it should be pretty easy to give them both a full stage 0 tune using parts from any Volvo car parts specialist (eg PFV)

Tim..

Sounds to me like a normal home car service is required, if the OP is up for it. Then maybe try and get a man in a van to come out and stick a Crypton tuner on it, if the boat can be backed up to a dock close enough to stretch the leads from the van?

Or alternatively can it be trailered or lifted onto blocks in a suitable location?

I'd bet that getting a marine motor engineer to sort it out would cost far more than a land based version... even though the engines are substantially the same.

Perhaps it's not getting any then. What sort of petrol pumps do they have?

Is there an electrical cut-off anywhere that could be faulty?