Loss of WOT RPM's

[aditchdoc]

1995 200 HP Ser # og076938. This motor was a formally EFI which has been converted to full carberated motor. The motor has run very well until resent. I'm turning a Fury prop 25P, the motor turned 5800 to 5900RPM's with top spped 65 MPH. Several weeks ago I had a blown head gaskets on the odd bank. After replacing gaskets on both sides verfying the heads were good ( compression on 1 thru 4 128 /lbs and on 5 and 6 134. With every thng back in order the motor only turns 5200 RPM's at WOT and at best top end has dropped to 59 MPH Ive got great spark, good fuel pressure, new fuel lines, filter and electric fuel pump. The loss of 600 RPM has me scratching my head as to where the power has gone Help at this point is greatly needed

RB

[JaySmithRacing]

RB,
Head gaskets come in different thicknesses you may have had more compression before ( Thinner gasket )

Just a thought !

Jay

[aditchdoc]

Thanks for respnding,

Actually the compression was approx 10 to 15 % less prior to changing the head gaskets.

[juanjuice]

also inthe summer you loose power

[EuropeanAM]

Don't overlook the spark plugs, either. They CAN be deceiving.... a fresh set would be a good idea before going too deep into diagnostic measures.