takeoff problems

[lmoreau]

Would a 1/2 to 3/4 of the way clogged fuel filter (the clear glass kind) cause bogging down out of the hole, but run fine at WOT on plane? With the motor trimmed all of the way down, and if you stomp on it, you only get about 3500-4000 rpms and about a 7-8 sec hole shot. Once it's up, it runs like a scalded cat. It's a 150 Merc. 89 model.

 

[KCLOST]

Re: takeoff problems

Could be....<br /><br />Also clogged low speed jets in the carbs??????

 

[JB]

Re: takeoff problems

Or a sticky stator not advancing the timing in synch with the advanced throttle.

 

[lmoreau]

Re: takeoff problems

If it was either of the two, why would it run perfectly fine at WOT on plane?

 

[KCLOST]

Re: takeoff problems

Prop and Pitch, and what type of boat...

 

[lmoreau]

Re: takeoff problems

18.5 ft bass boat, 4 blade turbo prop, unsure of pitch...not stamped on the outside. Pitch will allow 5600rpm at WOT with motor trimmed up.

 

[nbnewbie]

Re: takeoff problems

have same problem with 175 hp merc does your problem go away with the engine cover off? mine did changed the cover to engine seal

 

[lmoreau]

Re: takeoff problems

Hmm...is that maybe indicative of an exhaust leak? I'll have to try that.

 

[lmoreau]

Re: takeoff problems

Do you guys know what seals tbb is speaking about here? I took his advice and it made a really big difference. Much better accel from dead stop.

 

[KCLOST]

Re: takeoff problems

Exhaust Manifold Gasget/Powerhead Gasket....

 

[lmoreau]

Re: takeoff problems

Are these easy to change, or do they require major dissassembly?

 

[KCLOST]

Re: takeoff problems

Run the engine on the muffs with the cowling off... And see if you detect an exhaust leak anywhere. The exhaust manifold is in between the cylinder heads and the powerhead gasket is underneath the block....<br /><br />The manifold is the easier of the two, just removal of a bunch of bolts, clean things up and replace gasket. The powerhead gasket is tougher due to the fact of having to lift the block from the driveshaft housing...