Johnson 225 RPM's

[recke]

I seem to be losing RPM's on my Johnson 225 Venom (97). Originally, with my setup, it would easily turn 5500+. Then it was 5500. Now it is 5200 with all other things being equal. This is a light boat (Bullet) with a 4B 27 Renegade at 2" under pad. Motor has good compression (112-116 top four, 110 btm two) on a recent powerhead rebuild.<br />What things should I be checking?? Is there something in the computer that could be going wrong. Any info from you guru's out there would be great. Thanks

 

[R.Johnson]

Re: Johnson 225 RPM's

Providing there has been no damage to the prop, I would first check the sync. & link to see that nothing has got out of place, as the throttle plates not opening fully. If this proves OK, I would next do a leak-down test. This is a better indicator than a compression test.