Volvo Penta Timing and Dwell

[psmess]

Hello everyone(or anyone!),<br /><br />I have a 1974 25'Chris Craft Catilina with a Volvo Penta 260B. I need to know the proper advance timing as well as the proper dwell for the points. Also, as this is my first marine engine, where are the timing marks (TDC,etc.)?<br /><br />The engine idles fine but once I reach about 2600+ RPM, the engine starts to hesitate. The coil, points, condensor, distributor cap, altenator, fuel pump, batteries, and ignitor leads are all new, and I have also ruled out vapor lock or fule starvation. Any suggestions?

 

[psmess]

Re: Volvo Penta Timing and Dwell

Some more Diagnostics and info...<br /><br />The engine achieves high RPM in neutral, but it's when it runs under a load that it won't achieve power and plane and when it hesitates. The previous owner said he bought the boat from someone who also rebuilt the engine(has about 70HRS on it).<br />The engine has a Rochester Quad-Jet. Is this engine(8 cyl) basically a Chevy 350?<br />After reading some previous forums I discovered I could also try bypassing the fuel tank and use fresh fuel, but because of the rebuild I would like to check the timing and dwell first.<br />Another interesting thing I found in past forums...When I restart my engine after it has been running for a while, the starter barely turns over. I thought I had a seperate problem, but could this be the starter stuck in the flywheel thus causing poor performance at high RPM?<br /><br />Also, as a check for performance, what is the correct rocker arm gap?

 

[psmess]

Re: Volvo Penta Timing and Dwell

Also, what is a good idle rpm and red line for this engine?

 

[Don S]

Re: Volvo Penta Timing and Dwell

How high the rpm's are in neutral is a useless number and means nothing. It will keep on rising till the engine blows up. Marine engines also don't have red lines. The do have a spech for the max rpms the engine will achieve while on plane and trimmed properly with a clean boat bottom and a good prop.<br /><br />Dwell is 28° to 34° (I try to keep in the 30° to 32° range myself)<br />Timing at idle rpm is 8° BTDC<br />Idle Rpm 600 to 650<br />Advance timing is 30 at 4200 rpm.<br />WOT (Wide Open Trottle) rpm is 4400 to 4600 rpm. This is adjusted by prop diameter and pitch.<br /><br />

 

[psmess]

Re: Volvo Penta Timing and Dwell

Thanks for the info Don, this is very helpful for an airplane mechanic learning about marine engines. I can't find a repair manual for my engine.

 

[Don S]

Re: Volvo Penta Timing and Dwell

Locate your local Volvo Penta marine dealer and have him order you manual #773351 for your engine.<br /><br />There is a dealer locator link at the site below.<br /><br /> http://www.volvo.com/volvopenta/global/en-gb/

 

[Silvertip]

Re: Volvo Penta Timing and Dwell

Hydraulic valve lifters -- no gap but lifters must be properly preloaded. Service manual tells you how. Two ways to do it -- running or static. Running tends to be messy since valve covers are off. Static is best.