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Low RPM output on 305

M

Matt m

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I just bought a 1983 26 Shamro

I just bought a 1983 26 Shamrock with a 305 PCM v8. The engine has low hours and starts and runs great. The only problem is the max RPM that I am getting is 2500. Is this a typical problem with the engine? Where should I start? Thanks a bunch.
 
"It's a "a typical pro

"It's a "a typical problem with" boats that have been poorly maintained.

Start with cleaning/ checking the prop for barnacles (don't laugh--they have been severe this year) or bent blades. If that doesn't do it, start looking at the fuel system: Water in the gas, dirty filters, carb needs rebulding, etc. If that doesn't do it, look at the distributor timing with a light: Is the advance advancing properly, is it timed right, etc.

Jeff"
 
"If the bottom's clean and

"If the bottom's clean and the engine is running properly (as in fastjeffs post) try a different prop. Many shops will offer you "loaners" of varying size and pitch to get the correct one for your boat/engine combination. I intentionally turn at the slow end of my rpm range (4000-4400) with 3950 being my top end. My sweet spot of 2800-2900 rpm gives me adequate speed, range and economy. Good luck."
 
"..." I intentionally turn

"..." I intentionally turn at the slow end of my rpm range (4000-4400) with 3950 being my top end. My sweet spot of 2800-2900 rpm gives me adequate speed, range and economy."

Me too, slindemann. Lot's better gas mileage that way.

Jeff

PS: I'll bet you get lots of 'good advice' from people saying your motors are way over propped, right? What do they know!"
 
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