Volvo Penta Noise (chatter) and loss of speed (cavitation?)

[imported_erick]

I have a Volvo Penta 4cyl 3.0 Litre that has about 10 hours on it in my 1998 17' Larson Bowrider.

The boat gets up on plane and runs good but at about 3000-3500 rpms there is a chatter in the engine. It can usually be quieted by backing down the throttle.

Another problem, not sure if it is related or not, but the boat occasionally losses speed when cruising. The problem is fixed by backing down the throttle to neutral and then getting back up to plane and getting it cruising again. The engine and rpms do not seem to change, but the boat slows considerably.

Finally, on the last outing, I aquired an exhaust leak. I can feel air coming out near the exhaust manifold so I will be taking it off to change/inspect the gasket.

Note.
I did change the prop to a reconditioned one and had the same results.
- I did not change the u-joints when we put the new engine in but they seemed tight.

Thanks for any help/suggestions.

 

[tommays]

Re: Volvo Penta Noise (chatter) and loss of speed (cavitation?)

Has it had and tuneups i know its only 10 hours BUT i am pretty sure it could use cap/rotor/plugs/fuel filters ,check the timeing ect

Tommays

 

[imported_erick]

Re: Volvo Penta Noise (chatter) and loss of speed (cavitation?)

Has it had and tuneups i know its only 10 hours BUT i am pretty sure it could use cap/rotor/plugs/fuel filters ,check the timeing ect

Tommays

you would recommend that even if it was all done in august 2005?

 

[Don S]

Re: Volvo Penta Noise (chatter) and loss of speed (cavitation?)

Could be a slipping cone clutch in the drive. Have you check to make sure the drive itself is going all the way into gear?
Remove the back cover put shifter in gear (engine NOT running) and see if the linage is actually going all th way in. Turn it with your hand, don't just look at it.

 

[imported_erick]

Re: Volvo Penta Noise (chatter) and loss of speed (cavitation?)

I did check the linkage and actually adjusted a little more towards forward. it still does this. Can the cone clutch be slipping if the linkage is all the way in?

Thanks,
Erick

 

[crestapre]

Re: Volvo Penta Noise (chatter) and loss of speed (cavitation?)

How do you adjust the linkage and how do you know if its "all of the way in" gear?

thanks

 

[imported_erick]

Re: Volvo Penta Noise (chatter) and loss of speed (cavitation?)

found out the exhaust leak was really a head gasket. Whith that fixed, I still need to find out why it is losing speed and coming off plane:

"Another problem, not sure if it is related or not, but the boat occasionally losses speed when cruising. The problem is fixed by backing down the throttle to neutral and then getting back up to plane and getting it cruising again. The engine and rpms do not seem to change, but the boat slows considerably."

I have adjusted the linkage by openning the access panel on the outdrive and making the linkage have more throw into forward and still no luck.....any ideas?
Thanks,
Erick