125 Health Check

[gregmsr]

89 Force 125, Capri Cuddy 19'

If I can get 5500/5600 RPM @ WOT, with a 13x15 prop, 35mph, what would I expect the general health of this old motor is? Quick to plane but has some low idle issues (slight quiver occasionally at no wake speed, cuts off while docking occasionally after a run and heated up, sneezes during starting quite frequently).

Last compression check around 125 psi on all cylinders.

Good health?

 

[Bigprairie1]

Re: 125 Health Check

I don't think you are too far off there Greg. Those numbers would have been my speed estimate for that combo (boat/motor/prop).
If you are after more speed you might want to try a higher 17 or 19 pitch prop.
All in all that, apart from the idle problem, it looks like your motor is performing on target for its age.
My two bits.
BP

 

[Frank Acampora]

Re: 125 Health Check

A 17 pitch prop will drop your RPM to about 5200 which would be right in the middle of the recommended range and you MIGHT pick up another 2 MPH, then again, you might not.

Using the idle stop screw at the bottom of the timing and carb tower, raise the idle to 700-750 in forward gear in the water, approximately 800-1000 in neutral. Loosen the lock nut and screw in the screw 1/4 turn at a time, then open the throttle and back down to neutral after each adjustment, until you reach the desired RPM.

Clean or replace the plugs. They tend to foul easily so clean them religiously, like every couple of days running, or when the engine idle starts to suffer, or more often if needed.

 

[gregmsr]

Re: 125 Health Check

Ok thanks. Not really looking for more speed just curious as to general health. I feel its still pretty strong (runs like a sewing machine) but concerned with low speed issues. Iv'e read horror stories of major problems causing no wake speed issues. So,,,,,, a closer eye on spark plugs, check idle setting and enjoy!

I assume if I can reach those RPM @ WOT, I have no spark or compression issues, hopefully.

Thanks again.

 

[Scaaty]

Re: 125 Health Check

Frank..you description on the idle is a bit confusing (same boat..though 88..so maybe some diff 88-89 motors?), the idle adjust is down low on the tower shaft that runs up the side of the block. A single slotted screw, right about even with the middle of the bottom carb. Hard to see, all painted black.
That said, put a 17 pitch on it, and crank the idle up. Had same idle problems, but cranked up to a grand (boat tach, how accurate who knows) free wheeling, now zero problems, and shifting is fine, no clunk. Had mine out all day yesterday...and just purrs at 3500. Next year will be 21 years in saltwater...taken care of/flushed, and one of my best motors!

A 17 pitch prop will drop your RPM to about 5200 which would be right in the middle of the recommended range and you MIGHT pick up another 2 MPH, then again, you might not.

Using the idle stop screw at the bottom of the timing and carb tower, raise the idle to 700-750 in forward gear in the water, approximately 800-1000 in neutral. Loosen the lock nut and screw in the screw 1/4 turn at a time, then open the throttle and back down to neutral after each adjustment, until you reach the desired RPM.

Clean or replace the plugs. They tend to foul easily so clean them religiously, like every couple of days running, or when the engine idle starts to suffer, or more often if needed.