Do I need to adjust/ fix something or is this as good as I'll get

[HeavensFence87]

Hi all I mainly joined iboats to answer this exact question. I bought a 1985 Reinell Sunchaser with a 260hp 5.7L v8 that had so many problem I didnt know about when I got it. To my dismay the boat couldn't get on plane and only went to 10mph with only 3 people in the boat. I've since done the spark plugs, wires, points, distributor cap and rotor, and rebuilt the carb. My engine compression in the 120s for every cylinder.As it stands now my boat performs exponentially better. Its max speed is 42-45 mph my tach on the dash shows 4100 rpms. It does have a very slight bog right before planing where the rpms kinda hit a plateau for a second and then once reaching plane it's fine. The motor sounds great otherwise. The slight bog and the 4100 rpms with a 17p prop still have me mildly concerned though. I'd love to tune/ fix something if it will help my boat perform better but if this is as good as a 33 year old boat is gonna perform I'd like to know that too. Lastly I used an online slip calculator and my slippage was only 8% which seems low for my boat. I really appreciate any input.

 

[Scott Danforth]

your RPM's should be about 4600 RPM.

your probably either down a cylinder or have some other issue limiting WOT

start with the check list in the DIY stickies at the top of the forum

 

[alldodge]

compression in the 120s for every cylinder

I think your motor is just tired, would normally expect to see closer to at least 140/150 range

 

[Redrig]

Weigh your boat too, you may be carrying around a few hundred extra pounds of water logged foam

 

[HeavensFence87]

Thanks all I'm going to do some fuel tests in the near future and keep everyone posted.The manual says 135 psi for the cylinder compression I better check it again to see what I'm getting. I'll keep everyone posted.

 

[Maclin]

At 4500', still thinking you need to join a GM Car Club and mention you need to tune that Rochester for higher altitudes

 

[HeavensFence87]

I'll look into that as well

 

[Maclin]

The tuning will lean it out, right now it is probably a little too rich all the time, spark plugs will appreciate it. Not really any more power available, but the A/F ratio will be in a more tolerable range for combustion, and run-ability may improve.

Bit take a look at the spark plugs first, they are an excellent sensor to tell if the richness is affecting you. Yet.

 

[alldodge]

Your up high?
If so always good to know up front