Volvo Penta AQ205 in Falcon 23 SPC - no idle...

[Roger Westlake]

Mornin' all,
I have recently purchased the above carburettor engined boat and although she starts and runs just fine above 1500rpm she won't idle AT ALL below this engine speed. This means I cannot select a gear as the engine simply peters out as I bring back the throttle lever to the Neutral position. Makes no difference if the engine is hot or cold. Same problem all the time - no idle.
Any advice would be most welcome.
Many thanks...

 

[Davey boy]

Hi, what was the outcome of this please
Thank you
David

 

[CLB]

Dint think yiu will get a reply from RW, he hasn't been back since 2015. I would say it sounds very much like carb problem, possibly blocked idle jet.

 

[No Regrets]

It would be money well spent to pop it down to a carb specialist for a strip, clean and once refitted turn the mixture screw in all the way (gently) before turning it out two turns as a base setting.

Then adjust the idle once warmed up. Then try tweaking the mixture screw half a turn at a time until the idle rises up, before readjusting the idle.

Also worth checking the engine breathers aren't blocked, the oil hasn't become contaminated with petrol (which would make it run rich!) and as I'm sure you have, the air filter looks usable.

Tweak up the manifold bolts a bit too.

You can usually check if there is a manifold leak by running the engine and squirting bit of WD40 over the joint. If the revs change it's sucking in the WD40 from the leak...

Just check the timing and ignition components too.

I understand the OP hasn't been back, but somebody else may have the same issue :encouragement:

 

[Davey boy]

Awesome thank you very much for the great info ������

 

[Davey boy]

I'm not sure why there are ??? Symbols on my reply ? It was supposed to be smileys
Anyhow thanks again . Brilliant