40 honda not reach spec rpm

[crsprecision]

I just purchased a 05 40 hp outboard, under power it only tacks at 1975 rpm , the manual states 5500/6000 max rpm , if I disingage the gear it will rev much higher but not under load , the engine is new ,only 5 hrs I put on it . it seams the dealer doen't have to many answers as yet . any suggestions would be appreciated .

 

[crsprecision]

Re: 40 honda not reach spec rpm

Any suggestions , it came with a c3 - 11 - 15 prop on a 20' poontoon boat .... THKS

 

[Flounder pounder]

Re: 40 honda not reach spec rpm

See if you get any higher rpm in gear by slowing pulling out the manual choke when under way.

 

[Diesel Fitter]

Re: 40 honda not reach spec rpm

Sorry for the duplicate post, just don't know how to remove it.

 

[Diesel Fitter]

Re: 40 honda not reach spec rpm

I have the same issue with a 2004 BF50A that I just bought on a consignment sale through a dealer. On a Crest 20 Pontoon boat, it will max at 2200 - 2600 rpm depending on bay conditions and wind. I am leaning toward the prop being over pitched, and am going to ask the dealer if I can borrow and try a slightly flatter pitched prop. Don't need the boat speed, but do want the engine to reach a higher running speed. Engine revs OK in neutral, or with flush ears and the prop engaged.

 

[Bolt49]

Re: 40 honda not reach spec rpm

Did you guys find a fix? Seems that many of us are having this problem and seems like no one has figured it out yet.

 

[TD_Maker]

Re: 40 honda not reach spec rpm

Hey guys, I might be able to help a little. My dad has a BF40 on a 18' Bennington Pontoon. I just serviced the engine, so I know this information as fact. Dad is now turning 5500 RPMs with a 10 x 11 3/4 alum. prop (I am searching for a SS Prop for him.) It sure sounds like you are way over propped.

Also, when we pulled the boat from the water (After NINE years of floating) he must have scraped 100 LBS of algae etc... from the pontoons themselves. He was amazed at the difference in speed due to drag (of course, dad is 74 years old, so anything over an Idle is FAST!!)