rough runner bf 40

[snuffalupagus]

'01 bf 40 (honda) tiller, bought it used from a private party -two days ago-, changed oil and filter,gas filter, 'sparks' -so I would start out on the right foot- First time in the water, ran like a top. Later ( 30 min. )while idleing (fishing) coughed a couple of times and died.Started okay trolled for another half hour went to leave would run rough at any rpm but idle. Pulled plug wires one at a time #3 cyl. seemed to have the least "change' when removed. Emptied carb drain bouls. didnt help.I'm going to try it again tomorrow to see it it was a tempature issue(runs good cold but not hot).Feeling the head area around 1 and 2 cyl. were a lot warmer than #3. Do coils die with temp. Any other thoughs? --Don't ya just love fisrt time posters?-- Thanks for any help....

 

[Skinnywater]

Re: rough runner bf 40

Swap the spark plug positions see if the misfire changes from #3.
Or dig one of the old plugs out of the trash an install it back in #3.

 

[snuffalupagus]

Re: rough runner bf 40

Had put the old plugs back in,also the fuel pump has two outputs one to 1&2 carb one to #3 drained both of those lines ,#3 line gas was a bit cruddy,back to the lake, still ran rough mid range to high rpm. idled around (fishing again) drained #3 carb again tapped on the side of it to loosen what ever was in a jet or whereever, slowly (two, three minutes) running at full throttle cleared out what ever it was that was causing the problem- runs great again. HOPEFULLY problem solved..

 

[JUSTINTIME]

Re: rough runner bf 40

u need to clean those carbs asap

 

[Flakeys]

Re: rough runner bf 40

You may want to try a compression check on the cylinders and see what you get. Also check the valve settings.