89 force 50 Rpm question

[Tightliner]

Hi all , I am looking for a little help with my 89 force 50 .... I feel I'm not getting max power out of it ... Here is the situation ! I have 98 15' deep V aluminum Sylvan explorer that came with a 25 hp mariner which I've had nothing but trouble with. So this year. Decided to try my luck at a new to me motor ... I found and purchased a 89 force 50 in great shape and put It on my boat ... Put the boat in the water and is running great ! Once I found the proper trim position the boat planes and handles very nice ! With 2 larger adults I'm running about 22-23 mph according to my fish finder. That being said i was getting speed with the 25 and figure I should be getting more with the 50 hp ..The 50 is a little sluggish getting on plane but once up runs pretty smooth .... I have a 3 blade prop but not sure what the pitch is .... To me it just seems like the motor is not working at my assumed potential... When I got off the water and home I put the throttle down all the way and checked the throttle linkage ... With the throttle at full stroke I could still move the fuel arm ( sorry for the improper part name ) another inch . I assume this will allow more fuel to the carb and give me higher rpm resulting in a little faster out of the hole and a little more speed .... I also feel by extending the linkage rod I will have a higher idle speed .... My question is am I on the right track by extending the linkage rod to improve performance ... I have not done my own compression test but the previous owner assured me there was between 110 and 115 psi on each cylinder .... Again the motor seems to be working great but I just feel I should have a little more performance with the larger hp motor ..... Any advice or suggestions would be greatly appreciated ...

 

[Tightliner]

Also I should mention that starting the motor sometimes I had to engage throttle get the fuel in and motor idling .... Once Engaged in forward it would chug a bit and stall ... In order to troll I needed a little more fuel to smooth out the motor , however that resulted in a little too fast fr trolling ...

 

[scottmm73]

A link and sync of the carbs is probably necessary. However, if when the throttle is completely forward or at WOT (wide open throttle) the carb throttle plates should be completely horizontal. If this is the case more than likely the throttle is adjusted correctly. With that being said, I personally would not take the previous owners word to heart. I would replace the impeller, change the lower unit gear oil, test the thermostat for proper operation, perform a link and sync, check, set and adjust timing, and determine the proper prop for the motor.

The prop can be removed and the pitch should be stamped into the hub.

Oops forgot to add the link to the tutorial.

http://forums.iboats.com/forum/engi...ler-outboards/616464-carb-and-timing-tutorial

 

[jerryjerry05]

Don't take the old owners word on ANYTHING!!!
Do your own comp test.
Do your own spark test.
These 50's can and will run pretty good on 1 cylinder.
The motor could have come off of a pontoon and the pitch will be way off for a v-bottom boat.
Post results of the comp/spark tests.

 

[Tightliner]

I'll check the prop tomorrow , as for the spark both top and bottom have excellent spark .. In my opinion ! I'll check compression myself this week and get back. !!!! I'm pretty sure the motor was on a bow rider ...

 

[Tightliner]

I checked the carb and at full throttle the plates are horizontal , the spark on both top and bottom look great ... The prop is a Prop Michigan 072131 Michigan Match 072131 10-3/8" x 11-1/2" 3 Blade RH Propeller... I still haven't had a chance to check the cylinder compression yet ....