taylormade
Member
First, allow me to say "first time poster, long time lurker" and I've learned and tried a lot from this forum, so THANK YOU in advance, even if this post gets exactly zero replies.
Ok, so I have a late 90s BF40a that ran great when I bought it three years ago and then sat for a year until about 3 months ago. Never had ethanol gas in it and did have Stabil (just getting it out of the way). I knew the carbs were going to need to be cleaned so I didn't bother even launching it without doing so first. I also dumped the approximately 8 gallons of gas into my tractor. When I launched it, it would start right up, idle perfectly and cruise around with no problems until I got to about 2500 or so RPM where it would bog down and run rough.
I had a trusted mechanic come over, pull the carbs off and take them home with him where he put them in the ultrasonic bath and cleaned them thoroughly before installing and synching them. While it ran better, it ultimately didn't change all that much. Problem continued.
Replaced all the grey fuel hoses with new, high quality hoses as well as the fuel bulb, which is firm. Ran it off a 2G external tank, bypassing all the filters... no change. Did some more research and saw that the fuel pump could be the culprit. Threw $100 at it... didn't fix it.
Got the SeaFoam out. Nada. Yamaha Ring Free shock treatment. Nothing. Changed the plugs (which were actually pretty clean), nothing changed. Pulled one plug off at a time and there's definitely a drop in performance on each cylinder. Good compression in each cylinder and good spark (both on an inline tester and grounded to the block).
It's not making oil... oil is clean, normal level and doesn't smell of gas.
I tried spraying WD40 around the carbs while under way to see if there were any air leaks... nope.
Tried shooting carb cleaner in the carbs (removed the silencer) and sometimes it revvs a bit, others it boggs (assuming it's because they're full of fuel then).
Today I tried pulling the manual choke rod out when it's running rough and when I do so, just a tiny bit, it cleans it up a bit. It's still nowhere near where it's supposed to be, but it runs a little bit better with about an 1/8th choke.
All this brings me back to the carbs but before I pull them off AGAIN for the third time, is there anything else I'm missing?
Ok, so I have a late 90s BF40a that ran great when I bought it three years ago and then sat for a year until about 3 months ago. Never had ethanol gas in it and did have Stabil (just getting it out of the way). I knew the carbs were going to need to be cleaned so I didn't bother even launching it without doing so first. I also dumped the approximately 8 gallons of gas into my tractor. When I launched it, it would start right up, idle perfectly and cruise around with no problems until I got to about 2500 or so RPM where it would bog down and run rough.
I had a trusted mechanic come over, pull the carbs off and take them home with him where he put them in the ultrasonic bath and cleaned them thoroughly before installing and synching them. While it ran better, it ultimately didn't change all that much. Problem continued.
Replaced all the grey fuel hoses with new, high quality hoses as well as the fuel bulb, which is firm. Ran it off a 2G external tank, bypassing all the filters... no change. Did some more research and saw that the fuel pump could be the culprit. Threw $100 at it... didn't fix it.
Got the SeaFoam out. Nada. Yamaha Ring Free shock treatment. Nothing. Changed the plugs (which were actually pretty clean), nothing changed. Pulled one plug off at a time and there's definitely a drop in performance on each cylinder. Good compression in each cylinder and good spark (both on an inline tester and grounded to the block).
It's not making oil... oil is clean, normal level and doesn't smell of gas.
I tried spraying WD40 around the carbs while under way to see if there were any air leaks... nope.
Tried shooting carb cleaner in the carbs (removed the silencer) and sometimes it revvs a bit, others it boggs (assuming it's because they're full of fuel then).
Today I tried pulling the manual choke rod out when it's running rough and when I do so, just a tiny bit, it cleans it up a bit. It's still nowhere near where it's supposed to be, but it runs a little bit better with about an 1/8th choke.
All this brings me back to the carbs but before I pull them off AGAIN for the third time, is there anything else I'm missing?