Mid range power loss.....

[steve forsythe]

My 2000 carbed Merc 200hp runs and starts fine but has a terrible time maintaining half throttle. If i get it up on plane (4500 rpm) then ease the power back a little (3800 rpm) it wants to lose power and die down to 2800 rpm. If you feel it losing power you can increase throttle a little and it will power back up and run fine in the 4200-5800 rpm range. If i want to run slow, but still up on plane, i cant. Sometimes i can find the exact rpm's that it dies on (approx. 3750-3800) and it will die down and then kick back in for a minute or two, then die back down again without me touching a thing! Is this a linkage promblem, or could my throttle be bad? Any help i would appreciate. Thank you.

 

[steve forsythe]

Re: Mid range power loss.....

Just a note to clear up the fact that this is not a planing problem, it has only started losing power just receintly, and it is a noticable power loss, not just falling off plane.

 

[sloopy]

Re: Mid range power loss.....

maybe the carbs are not adjusted right? 3800 might be when the butterfly valves open on a bad carb?

 

[steve forsythe]

Re: Mid range power loss.....

All the carbs were just adjusted, so im thinking they are fine, but maybe that caused the problem? Someone told me something about synchronization & timing, is there something that needs adjusting on a regular basis? The engine just runs very intermitantly at mid rpm's. You either have to give it a little more gas or let off the throttle and come off plane. Could it be the throttle??? It is a quicksilver and is not all that smooth.

 

[sloopy]

Re: Mid range power loss.....

its the timing, it has to be re check the idle screws and stuff and the butterfly valve opening