Losing RPM's 1993 5.0 litre

[markp0730]

I need help, I have a 1994 195 sundowner with a 5.0 litre V8, carburated. I have been losing RPM's on the engine. it should run 4000 to 4400 per engine specs. I may get 3600 out of it. The boat brand new came with a 19 pitch prop, ran fine. I had mechanic look at it. He put a 17 pitch prop, kind of cured it, but still only get maybe 3800. Compression has been checked, fine. carb has been rebuilt. Still runs low.... what can be the problem? I have read that a "coil" could cause the loss in RPM's? is this true? what checks am I missing to find the problem? Also. the boat specs call for a 19 pitch prop for boat. I believe mechanic was just dropping down to pick up the RPM's. pleas help

 

[Haut Medoc]

Re: Losing RPM's 1993 5.0 litre

You are right about the mechanic, he just changed props to pick up rpm's & masked the problem....<br />I would get a new mechanic for starters....<br />Who rebuilt the carb?<br />Post the engine serial # so we will know exactly what you have.....<br />Welcome to iboats, btw ......JK

 

[markp0730]

Re: Losing RPM's 1993 5.0 litre

Actually the mechanic that changed the prop also was the one whom rebuilt the carb. When I did get the boat back and took it out, I was running almost 5000 RPM's. So I thought great he fixed it. and I knew the excessive RPM's were because of the 17 pitch prop. But after a few trips out on the boat. it went back to the situation of maybe 3600 to 3800 RPM's. It seems at the start of a day out on the water she runs fine. Just after running for awhile or starting and stopping and starting again while skiing it will lose power. I will get serial # and post, what does serial# have to effect engine? Thanks again for the help.

 

[Haut Medoc]

Re: Losing RPM's 1993 5.0 litre

It will tell us exactly what you have...<br />It does sound like a fuel delivery issue, though....JK

 

[markp0730]

Re: Losing RPM's 1993 5.0 litre

is it at all possible that the coil can be affecting the RPM's? I will post serial when I get home

 

[Mischief Managed]

Re: Losing RPM's 1993 5.0 litre

Originally posted by mark p0730:<br /> is it at all possible that the coil can be affecting the RPM's? I will post serial when I get home

Yes it is. Not the most likely culprit, but cheap enough to replace as an experiment.