Honda 30 Hp 4 stroke only does 7 mph

cowarren35

Recruit
Joined
Nov 2, 2009
Messages
2
my Honda motor is pushing a 14 ft aluminum boat and will only go 7 mph. The motor starts fine runs fine but when you open it up it dont go the motor is running fine just doesnt seem to pick up RPm's. Please help
 

Mas

Lieutenant Commander
Joined
Oct 3, 2006
Messages
1,656
Re: Honda 30 Hp 4 stroke only does 7 mph

Spun prop hub or sheared prop pin! Remove the prop and check the pin. If the pin is OK, put a mark on the inside and outside of the prop. Run the motor on the water and see if the marks move in relation to one another. If the marks move, the hub is spun which can be rehubbed at a prop shop.

MAS
 

cowarren35

Recruit
Joined
Nov 2, 2009
Messages
2
Re: Honda 30 Hp 4 stroke only does 7 mph

Thank you for your reply. How do you mark it with a marker or scratch the aluminum.
 

psteurer

Petty Officer 1st Class
Joined
Nov 10, 2008
Messages
366
Re: Honda 30 Hp 4 stroke only does 7 mph

A scratch would be best. But you could try a permanent marker at first and see it that works

Do you have a tachometer on your boat? If you have a spun prop, the motor will have a high rpm. In your first post, you say you are not increasing rpms. I am thinking, you could have a carburetor issue. The Honda carburetors have very tiny passages for the fuel to go through. Does the boat sit for more than 2-3 weeks at time without use? When I bought my Honda 50, the dealer said the number one problem with these motors is fuel sitting in the carburetors and clogging them up. He said to either drain the carburetor of run it dry if the motor was not going to be used in 2-3 weeks.
 

zzzzz

Lieutenant Junior Grade
Joined
Jan 13, 2003
Messages
1,094
Re: Honda 30 Hp 4 stroke only does 7 mph

I would have to say that you need a different pitch propeller...is it a vee bottom boat or flat bottom ??:cool:
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Honda 30 Hp 4 stroke only does 7 mph

If its reving but not making speed it could be a spun hub.
Mark it with an indelable marker.
Check that it is running on all cylinders.
 
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