Jetting 85 hp force carbs...

[my1stboat1]

Im curious guys.... Im a motor head been that way for ever... always tring to make this faster that better whatever... Ive had 10 sec cars... 9 sec bikes and dirtbikes that ive always tinkered with...

SO MY ? IS..... CAN THE FORCE CARB JETS BE SLIGHTLY OPENED LIKE EVERY OTHER ENGINE IVE MESSED WITH EVER SO SLIGHTLY FOR THAT ADDED BIT OF FUEL AND POSSIBLY HELP PERFORMANCE...

thanks

 

[huskerdaninva]

Re: Jetting 85 hp force carbs...

Obviously you can play with the jets, but being a 2-cycle engine I don't think you'd gain anything noticeable. You'd have to get inside the engine and work on the porting a little bit to even begin to see anything appreciable in HP gains. One man's opinion...

 

[my1stboat1]

Re: Jetting 85 hp force carbs...

and i definitly appreciate your opinion, Thats whats so good about sites like this.... input helps... I only ask cause ive jetted 2 stroke single cylinder dirtbikes and have seen gains... Mostly in throttle response... But a gain is a gain.. Thanks

 

[Barnacle_Bill]

Re: Jetting 85 hp force carbs...

Check with the guys at Scream and fly.com. That's what they do.

 

[Frank Acampora]

Re: Jetting 85 hp force carbs...

On a stock Force engine, the jets are sized to LIMIT fuel delivered at full throttle. because of the timing advance and throttle advance geometry, timing is at full advance somewhere around 3/4 of the control handle movement while the carb will be opened only about 1/4 of the way at this same point. At this point, not enough air is flowing through the venturis for them to functin properly so the low speed circuit is doing most of the work. This is sometimes referred to as "cruise" or "economy." Opening the throttles all the way makes a lot more noise and uses a lot more fuel while only increasing speed a couple on MPH.

Now, these engines usually run a bit rich and use a lot of fuel. Opening the jets on a stock engine or even on a ported one will do absolutely nothing. For example, I was also curious and on a ported four cylinder engine I opened the jets from .094 to .100. Result: No change in performance for better or worse.

The three cylinder engines are very old school design and respond beautifully to porting. If done correctly you can gsain between 5-10 HP PER CYLINDER.

 

[my1stboat1]

Re: Jetting 85 hp force carbs...

hey frank .. are you interested in doing the port work On my 85 hp force... Ill bring your the power head or boat whichever you want.. im just looking for alittle more out of the motor and not having to just put the 90 hp on it that it states i can go to ...