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BF50 high rpm miss

C

Cabinetman1955

New member
My bf50 has a high RPM miss. Plugs are Clean,has new canister fuel filter, drained carb bowl's checked for any visible problems no loose wires any suggestions?
 
Replace your plugs with new ones, get the correct ones. Plugs can play up even if they look clean. Do you have a choke? Next time your out on the water, go full throttle and then gently pull on the manual choke on the outboard to enrich the fuel mix. If your motor starts to run better during this process then your carbies need a clean. Also check for air leaks around the carbies and intake manifold. You can use a can of starter fluid to squirt around the gaskets while the motor is idling and listen for a change in revs, if your hear one then you have found an intake leak. Test your coil pack resistances and make sure they are all the same, it's more likely a fuel issue but his is an easy and cheap test to do. Make sure your fuel tank breather is open!
 
Agree 100% about trying new plugs. Hondas can be sensitive to plug condition. Use NGK brand only if you want reliable results.

Have you checked the primer bulb while this is happening to make sure that it is staying hard and not losing fuel prime? If not, try squeezing the bulb a few times with symptoms occurring to see if that helps.

If it does and/or the bulb is soft, first check your tank vent screw or run it with fuel cap temporarily loosened to make sure it isn't a venting issue. If vent is ok but bulb still gets soft, you either have an air leak on the "suction" side of the bulb or the bulb itself is weak.

If you have a water separator, that can be a source of fuel prime loss (air leak) or it may be overly contaminated and needs serviceing.

Good luck.
 
Trim is down completely, at full throttle the RPM goes from 5000 to 6000, and not right away, sounding like I raised the trim all the way up?
This is at 15 to 16 mph top speed!
Can you help please.
 
Sounds like you may have a spun hub. Hit anything with the prop lately?

Put marks on inner and outer hubs then go for a spin. If the marks are misaligned afterwards, you'll need a new prop.

Good luck.
 
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