Volvo penta/ air blowing out of carb

[corbin5754]

trying to start my volvo penta 4 cyl aq131a. When i try to turn it over air puffs out the carb, when it should be sucking in air right. please help if anybody knows what my problem is

 

[a70eliminator]

Re: Volvo penta/ air blowing out of carb

Puffing and spitting out the carb is a timing issue, either valve or ignition, usually.

 

[TowRoper]

Re: Volvo penta/ air blowing out of carb

hiya, if its not cranking fast enough it will seem to blow air out also if there is a valve stuck open it will also do that maybe even a head gasket i would do a compression and leak down test that will get you closer to the problem
good luck mate.

 

[tom travers]

Re: Volvo penta/ air blowing out of carb

i had the same problem, but a volvo 6 cylinder, triple solex carbs, tried everything, talked to a volvo certified mechanic, he told me to set the points at 16 degrees, the boat has run great ever since. It's amazing!

 

[cr2k]

Re: Volvo penta/ air blowing out of carb

Uaaa? 16 degrees? Of dwell? Or .16 in gap?

Other cause would be a burnt or stuck intake valve.

 

[corbin5754]

Re: Volvo penta/ air blowing out of carb

my mechanic wants to check the timing belt could that be the problem.

 

[Robj]

Re: Volvo penta/ air blowing out of carb

Sounds like timing. If your engine uses a belt instead of a chain it could very well have "jumped time".

DITTO Check the timing belt.

Have a great day

Rob.

 

[bruceb58]

Re: Volvo penta/ air blowing out of carb

Timing belts just don't jump. I really doubt it would be the belt unless someone installed it wrong.

What is the history of this engine? was it working properly and then one day it stopped running?

What are the compression numbers? Can you do a cylinder leak down test? Might be nice to know if there is a bad intake valve.

 

[Bifflefan]

Re: Volvo penta/ air blowing out of carb

got to go with Bubba on that. the belts will jump, anytime they are worn or old.
I think its a belt or a sticking intake valve. but the belt sounds more likely.
roll it over and line up the marks and then you can see for your self.

 

[corbin5754]

Re: Volvo penta/ air blowing out of carb

ok we found the problem theres a piece missing like a guide on that goes behind the pully to keep the belt in line and the only thing keeping the belt on is the heat exchanger made a nice groove in it so all i need is that piece probably find one at boat salvage yard. my mechanic said same thing. it jumped time bought the motor off ebay so dont know the history on it

 

[bruceb58]

Re: Volvo penta/ air blowing out of carb

So how did you determine it jumped time and what is your definition of jumping time? Did you compare the dots on the cam pulley with the dots on the crankshaft? There is one more pulley which is the one that drives the distributor. That one is actually not critical since if you are off by one tooth, you can compensate by turning the distributor when you time your engine.

I am very familiar with these engines because I worked on many Volvo cars which had the same engine. The belts would break way before they ever stretched and jumped a tooth. They would last a LONG time before this would happen too. Since the engine in not an interference engine, a belt breaking is not catastrophic.

 

[Don S]

Re: Volvo penta/ air blowing out of carb

Those belts should contact the guides, and some engine don't even have them. If the belt is pushed to one side of the pulleys or the other, you need a new tensioner, and a new belt since the edge is worn down for rubbing.
Bad tensionser also cause the belts to be loose, and jump a tooth at times.

 

[corbin5754]

Re: Volvo penta/ air blowing out of carb

All I know is i went to the boat salvage yard bought a tension pully and plate that goes behind the bottom pully now the engine will turn over and start, but now looks like fuel pump is no good so i gotta buy another fuel pump ill get it running someday

 

[corbin5754]

Re: Volvo penta/ air blowing out of carb

Had the boat running for about a week now when i try to start it it just turns over and wont start, and as im trying to start it the carb coughs out smoke now whats wrong with it .

 

[kevman]

Re: Volvo penta/ air blowing out of carb

I know its been a while since someone posted but what color is the smoke? Black smoke usually indicates too much fuel. Maybe its flooding. It could be flooding because there is no or little spark. I would check points and see if there is spark.

Kevin