Low rpm @ WOT

[fabolous024]

Need some advice/opinions. Recently purchased a used boat. Motor is a 2005 Yamaha 90tlr two-stroke. Motor starts everytime. When I have the freshwater hookup(earmuffs), the motor idles fine, and will rev up to 5000-6000rpm in gear and neutral. However once I get it in the water I'm only getting 2500rpm. Any suggestions??? I'm guessing it might be wrong size propeller. Currently it's 13.5x23.

 

[Bob_VT]

Re: Low rpm @ WOT

Welcome to iboats.....

Never rev up an outboard on the muffs....it can do severe damage.

Any outboard can run on less cylinder's while not under load and sound normal and even rev up however it is not an indication that all cylinders are firing.

I would get a static timing light and verify spark on all cylinders and do a compression check on each cylinder.

Your prop has nothing to do with this at this point.

 

[mibugnu]

Re: Low rpm @ WOT

Same thing happened to my pontoon. When u are in the water, open it up to the wot (of 2500 rpm) then push the choke in. If the rpms go up your carbs are dirty and need a good cleaning.