85 hp force motor eating 6 gallons of fuel in an hour, and 22mph top speed?

[bradyz25]

its pushing a 16ft sea nymph some one took apart the throttle control and messed around in there but idk if thats whats causing it to eat gas or only go 22 mph. i was told she should at least be in the 34 mph range. boat aint that big.

 

[Ibl0wstuffup]

Does it ride low in the water? Maybe there's water trapped in the boat. Does it run smooth?

 

[jerryjerry05]

Welcome.
First do a compression test.
Spark test.
Then check the fuel pump diaphragm.
A 16ft with an 85 should do 35-40.
If the foam under the deck was saturated it would have to have 2000# of water to make it that slow.
Top post in the Force Forum is a couple of self help posts.
Look up the link and sinc one and check it out.
Check the fuel system for old and damaged hoses.

Post the results.

 

[achris]

The 'divide by ten' rule of thumb for fuel consumption of a 2 stroke at full noise has this engine sitting in about the right place. 85hp/10 = 8.5 gallons per hour at WOT. You used 6 gallons in an hour. Sounds about right. As for the vessel speed, that's not right, the guys above should have you on track for that.

Chris......

 

[HotTommy]

I have nothing specific to add, but here is some food for thought. If it is using less fuel per hour than average at WOT ( 6 vs. 8.5) and it is running slower than expected, perhaps there is a connection. You may not be getting full WOT and that could be related to the work on that throttle control that you mentioned.

 

[Jiggz]

The best reference to use if a motor is actually running at its optimum is the RPM and speed over water or GPS speed. An 85 HP Force is rated between 4500~5500 RPM at WOT. How fast it will run a boat on those rpm's depends on size, load, trim and sea conditions. But normally that speed should be around 35~40 MPH. So the first question is what your WOT RPM?

 

[bradyz25]

have one more question guys. my transom from top to bottom of v is 22 inches, if I get a motor do I get a long shaft or extra long shaft? I dont buy the wrong thing

 

[bradyz25]

i know that plate on lower unit should be right at the bottom of the v

 

[achris]

have one more question guys. my transom from top to bottom of v is 22 inches, if I get a motor do I get a long shaft or extra long shaft? I dont buy the wrong thing

Extra long, and raise it up on the mounting bolts the extra couple of inches.

Chris.....

 

[Jiggz]

i know that plate on lower unit should be right at the bottom of the v

This is correct with a plus or minus 1/2" leeway.