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Gas in oil Honda BF 50

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bcmschmidt

New member
"i have two problems with my h

"i have two problems with my honda bf 50

1) i do have gas in oil. i changed the oil and filled in up only 3/4. after 4 hours of running the motor the oil level was up to full, so roughly 250ml of fuel added to the oil

2) the motor runs fine in idle and also in gear at 1200 rpm, but when trying to power up the motor dies off

any advise?"
 
The fuel pump diaphragm has a

The fuel pump diaphragm has a small hole in it allowing fuel to pass thru the pump into the crankcase. When you pull the pump you will find it very clean and smelling like fuel.
 
"checked the pump and the diap

"checked the pump and the diaphragm looks fine and the pump is not loosing any pressure, which it should, if there is a leackage to the motor.

also did a basic cleaning of the carbs, but did not change anything"
 
"so engine is running fine now

"so engine is running fine now, when it comes to acceleration.
Changed the fuel, fuel filter, fuel lines and cleaned the tank. the fuel was apparently too old.
as per gas in oil issue i have not checked yet. i changed oil and need to run the engine for some hours to check."
 
"If your engine sat with the f

"If your engine sat with the fuel line hooked up and the vent closed, you might have had some heat expansion push gas thru the carb and past the rings into the oil pan--? The cure is "don't do that""
 
"One other consideration - if

"One other consideration - if the engine is running cold because t-stat is stuck open, that will dump some gas into the oil. Make sure your t-stat(s) are operating properly."
 
"Thanks for your suggestions.

"Thanks for your suggestions. My gas is new, tanks are vented and engine starts and runs great (so I think the t- stat is OK). I plan on checking compression, cleaning the carbs, and if that doesn't clear it up replacing the fuel pump. My understanding is you can't get a carb kit. Honda only sells the whole unit."
 
"so if the engine is running f

"so if the engine is running fine, i don;t think the gas comes from the carbs. one of the floater would have to be defect and therefore too much fuel would get into the system.

check your fuel pump. it is easy to dissamble and too check whether it is working or not (takes 30 min altogether)

the other option is that your fuel system might create too much pressure, i.e. through heat or using the manual fuel pump you pump fuel through the sytem, e.g. if your fuel tanks are full and exposed to sunlight and you have the vent closed fuel might get through to the engine"
 
Easy way to check pump...loose

Easy way to check pump...loosen bolts that mount to block gently squeeze fuel primer bulb...no gas should leak out...if it does the diapham is shot...often you can't tell visually if it is perferated..unless you have a good magnifing lense.
 
"thermostat back port side on

"thermostat back port side on top under cover, 4 bolts cover, 2 for thermostat

pressure checked my engine 110, what should they read"
 
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