2006(90 HP) 4 stroke Honda,Low RPMs

[Jim Briggs]

J b

 

[cp]

Re: 2006(90 HP) 4 stroke Honda,Low RPMs

Not sure what you mean by "Motor has been checked out...." but if you're sure the motor has adequate fuel delivery and good spark, then the other needed component is air. Have you checked whether your motor is 'breathing' freely, meaning there is no intake or exhaust restriction? A motor with restricted intake or exhaust will not be able to attain rated RPM.

 

[Jim Briggs]

Thanks

 

[cp]

Re: 2006(90 HP) 4 stroke Honda,Low RPMs

Since the motor RPM does change in response to a prop change, it seems the motor may be running properly. Could it be that the boat is too much of a load? Is this a boat/motor combo you've had for a while; has this motor ever reached WOT range of RPM on this boat? Seems possible that neither the prop shop nor Honda has seen your boat, but perhaps the mechanic has seen your boat and may be on the right trail regarding it being too heavy a load for the prop you have?

BTW, Honda specifies carbureted BF90 full throttle range as 5000-6000 RPM (see this link); anywhere in that range is satisfactory, so you're only 450 RPM below the specified range. Once you get within the specified 5000-6000 RPM range, you won't be gaining any more torque and very little, if any, horsepower out of increasing the RPM. Instead, you'll just be increasing the wear rate on the motor. Just my 2?.

One final thought - is your tachometer reading correctly; have you verified the RPM with another known-to-be-good tach?

Good luck, let us all know how it turns out.

 

[Jim Briggs]

2006, 90HP_ 4 Stroke Honda , RPM Issue

2006, 90HP_ 4 Stroke Honda , RPM Issue

Thank You :

 

[Jim Briggs]

Re: 2006, 90HP_ 4 Stroke Honda , RPM Issue

Re: 2006, 90HP_ 4 Stroke Honda , RPM Issue

Part of problem solved

 

[Jim Briggs]

Re: 2006(90 HP) 4 stroke Honda,Low RPMs

;kl'jhgffh';l

Since the motor RPM does change in response to a prop change, it seems the motor may be running properly. Could it be that the boat is too much of a load? Is this a boat/motor combo you've had for a while; has this motor ever reached WOT range of RPM on this boat? Seems possible that neither the prop shop nor Honda has seen your boat, but perhaps the mechanic has seen your boat and may be on the right trail regarding it being too heavy a load for the prop you have?

BTW, Honda specifies carbureted BF90 full throttle range as 5000-6000 RPM (see this link); anywhere in that range is satisfactory, so you're only 450 RPM below the specified range. Once you get within the specified 5000-6000 RPM range, you won't be gaining any more torque and very little, if any, horsepower out of increasing the RPM. Instead, you'll just be increasing the wear rate on the motor. Just my 2?.

One final thought - is your tachometer reading correctly; have you verified the RPM with another known-to-be-good tach?

Good luck, let us all know how it turns out.

 

[Jim Briggs]

Re: 2006(90 HP) 4 stroke Honda,Low RPMs

Problem Solved

 

[Jim Briggs]

Re: 2006(90 HP) 4 stroke Honda,Low RPMs

Sure, felt like we were very close to getting the motor fixed,
I will keep you'all Posted.

 

[Jim Briggs]

Re: 2006(90 HP) 4 stroke Honda,Low RPMs

As you know I brought my boat back to the service center .
Carbs have been cleaned, & should be ready to go as soon it's complete.
THE PROBLEM= Rubber in gas tank / fuel filter / ( 10 Mic ) fuel-gas
seperator / Carbs etc;.
REASON = New hose from Gas tank to gas-water seperator, Fuel Seperator to motor is DETERIORATED . It's hard to know, That a ( NEW ) hose, Put us through so much trouble & Myself through so much expence . Hose was suppose to have been the right one.The HOSE is old, And off the shelf. I'll keep you Posted.
By the way, Fuel was treated with STAR-TRON ....................

 

[Jim Briggs]

Re: 2006(90 HP) 4 stroke Honda,Low RPMs

Reply to C.P. = < DETERIORATED FUEL HOSE >
Should have made myself a little more clear.
Around the 06/10/2010 , I bought a New Fuel hose, clamps, Fuel-Gas seperator, hose to motor connecter, From a Honda Dealer other then < F C J Marine > The parts man there told me, ( At that Honda Dealer )It is the right hose, I bought it & and ( I ) installed everything myself before
I ran the motor. REASON = Circle D Boats, Installed the motor they sold me, Charged me $100.00 to clean out the gas Tank. They left a residue in the bottom of the built in tank, That tank could have been removed and cleaned out with no trouble at all. Back to the Hose, Every one knows what NOS means, Well this time it's ( Old On Shelf ), The dealer just a mistake, That's all...........I Just Have to Grin & bare it
F C J MARINE, DID NOT SELL NOR INSTALL THE HOSE . FCJ are good people & I will send my best friend there, If need be. Think you for your support, And I will keep everyone Posted on what happens next.
Jim Briggs

 

[Jim Briggs]

Re: 2006(90 HP) 4 stroke Honda,Low RPMs

A Rubber hose, bought at a local Honda parts dealer, Cost us in the excess of $ 1000.00. But FCJ Marine in Kemah. Texas, stayed with the problem. It's now running 5600 RPM, And about 25 MPH. Were Happy, It now has the proper type fuel hose .
Now if this 4 stroke, 90 gives me the fuel mileage im hopeing for, There will be a smile on my face.
Jimmy Hudson
FCJ MARINE
Kemah, Texas
1 832 864 2679
I WILL BRING MY BOAT TO FCJ WITH OUT EVEN THINKING ABOUT IT TWICE , AND THATS A FACT, GOT IT !
JIM BRIGGS

 

[cp]

Re: 2006(90 HP) 4 stroke Honda,Low RPMs

Great news for you; you must be stoked to finally have your motor running the way it's supposed to! Guess you'd better buy your parts from FCJ too, in the future.

 

[Jim Briggs]

Re: 2006(90 HP) 4 stroke Honda,Low RPMs

great news for you; you must be stoked to finally have your motor running the way it's supposed to! Guess you'd better buy your parts from fcj too, in the future.

think you , for your 2 cents,
but you need to understand that before you make a statement like you have about where i brought my boat for repair , you need to know what your talking about here sir. Fcj marine has bent over backwords to get my honda right. Took it out today. Four ghrown ups & she still runs 25mph, as a fact my wife asked me to slow down. The 90 honda has all i won't, & fcj help make it happen. Think you.