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2004 Honda 9.9hp 4 stroke

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Stinger42

New member
Hi folks, hope someone can help me out here. I installed a new carb, figuring it would be the solution. It fixed the rough idle and throttle response significantly. But still has problems maxing out rpms underway. Not sure if the load is the cause, 2 battery's,elec,motor,3gal tank, and my 240 pound FA. The motor runs great with the cups on, on the trailer. Just wondering if someone thinks that there is too much weight in the back of the boat(14' alum v-hull 220 pounds) for this motor to get it to plane?? Wondering if because it cant plane it out, is the reason why it's not performing the way it should? Or could there be a motor issue...has good compression I might add.

Thanks for any help.
 
Make sure that when the motor is in gear, you are getting full throttle on the engine. You do not have to run the motor to do this. Make sure you turn the prop by hand when you shift it into forward....then see if the lever on the carburator is going all the way to the stop when you advance the throttle all the way.

Most likely, the weight and/or its distribution could be hurting any potential planning. Try removing the batteries and electric motor and move the 3 gallon tank as far forward as possible for a test run to see what happens. It there is an improvement, you may want to consider moving the batteries up front if there is room. During the experiment, you might try to locate yourself as far forward as you can (again just for a trial) to see if you can get it to plane.
If it does plane with lighter weight but not a change in weight distribution, then a change in prop might help.

The 2004 should already have a four bladed prop, which helps to pick up the back end.

What size prop do you have on it? The standard is 91/4 x 8. If all the moving around of things does not help, you may have to try a lower pitch prop.

Honda has a 91/4 x 7 pitch and also a 10 x 7 and 10 x 6.5 (for very heavy loads).

Mike
 
Pretty sure Mike is steering you in the right direction on all points.

I would only add that with the hull and motor combo you have, weight distribution is absolutely key in getting her to plane. I work on 12' old heavy Gregors with BF8 D's and, while the 8 horse is plenty of power to plane the hull with one occupant, it will not happen if I sit on the aft bench. I purchased a throttle/tiller extension so I can sit more forward and the boats pop right up and haul the mail.

It takes some getting used to but it works. Very important that you utilize the kill lanyard as these extensions put you farther away from the motor making it necessary to move aft when docking or maneuvering in close quarters.
 
It was definitely the weight distribution. I took it out on the river today with everything as far forward as possible and holy smokes what a difference! Thanks Mike and jgmo for pointing me in the right direction.
 
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