459cc Carb

bbirder

Member
Hi, New member here. Not a kart racer but thought with all the experience on this board I might get a solution to my problem. I purchased a HF 459cc engine and installed in a UTV. Everything worked out well except the Carb. Couldn't get the needle valve to hold pressure. Tried fuel pump, graviity fed w/no luck. Kinda hit and miss. Never knew when the cylinder was full of fuel when you got ready to crank it. HF sent me two carbs, both of which were wrong. While still under warranty I got them to replace engine. Second one has same problem.
Any thoughts on a solution to my dilemna? Does anyone know if a different carb would work on this engine? Thanks for any responses!
 
^^^That’s what I did on my riding mower. Does your carb have the electric selenoid on the bottom of the bowl? Not sure if the selenoid was the problem or not, but the in-line valve cured the problem.
 
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Depending on the the style the solenoid may not stop the fuel .
The honda i had apart Saturday it only stopped it from getting to the jet .
The needle and seat were still allowed fuel .
Its likey a sealing issue with the seat/ needle .
Inspect the needle , polish the seat with toothpaste and a q tip .
Make sure the bowel and line are clean .
Add a fuel filter.
 
If in fact the electric fuel shut off does control fuel delivery it and or the needle /seat are leaking .
Same cures .
 
Thanks for all of your thoughts. Carb does not have bottom electric shutoff. It does run well otherwise. I added a N.C. solenoid inline on the fuel but sometimes still leaks at needle and the solenoid gets hot keeping it open w/12v on it. Flattop1, I'm going to try polishing the seat like you suggested. These oil changes are getting to be a PIA and also expensive. Bowl and fuel clean as a whistle and using no ethanol fuel.
 
This is the Honda carb .its of a 2 cylinder genarator . Not mine so can't measure anything.
Probably find on via Google.
 

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Rubber tip needle or steel?
Any mark in rubber will leak .
Fuel must be syphoning in .
Could add a fuel line loop above the carb.
 
does the engine sit flat and level? Is the fuel tank below the cab (fuel pump setup) or is the gas tank above the carb and how big is the tank (gravity fed version)?
 
The gravity fed tank is stock tank (approx 1 gal) attached to engine slight`ly above. Currently running fuel pump on 5 gal tank well below the engine. Have fuel pump stopping a full 5 seconds before engine stops.
Flattop, would you explain the fuel loop?
 
Run the fuel line up to a point well above the engine . Then back down to prevent syphoning. A U loop.
So your using electric pump.
Should probably change to vacuum operated .
 

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There is a manual shutoff but it is very inconvenient to get to. Every stop I would need to get out and walk around the buggy to turn it off Itis built onto the carb. I had to modify the choke because there is no aftermarket adapter available yet.
 
Rubber tip needle or steel?
Any mark in rubber will leak .
Fuel must be syphoning in .
Could add a fuel line loop above the carb.
Polished the seat today and also put the loop in my fuel line. Won't know or awhile because the problem didn't show up every time I stopped it. But I did find that fuel was leaking past the pump and shutoff valve when I tried a piece of clear fuel line. While I was at it I installed a loop above and around carb. I also plan to go to a vacuum fuel pump. Didn't have the proper fittings to tap in. I've got to whip this.
I replaced a 23hp twin subaru EH65 with this 15.8 hp single cylinder. I can't notice any difference in performance for what I use it for. It has plenty of torque and seems to pull just as well with less gas. It will go from 0-25 in 300 ft and that what the twin did. Perhaps the twin performs betterin hilly country, but our land can't get any flatter.lol
 
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