running rough when throttling up

[renegade15]

I have a 1990 70hp johnson on a renegade flats boat that runs rough when you start to throttle up, intermittently. My neighbor is a car mechanic and he said it sounds like one of the carb floats is stuck and causing that cylinder to run real lean. It sounds like a 2-stroke dirt bike until you come back to idle, then it is nice and smooth. Of course if you turn it off and start it back up it runs fine. Pumping primer bulb does nothing and I just put new plugs and wires in. Anything else it could be? I was going to rebuild the carbs and noticed I can get the sierra kits for a little less than half of the evinrude/johnson rebuild kit, is the factory original really worth double? Thanks in advance!

 

[renegade15]

Re: running rough when throttling up

No takers??? Atleast on the sierra versus oem parts question? I found the sierra kits for $12.05/ea and the part from bpo is $24.99/ea. Any reason to spend double, times three?

 

[tx1961whaler]

Re: running rough when throttling up

Sierra kits are just fine for what you're doing.

 

[Mas]

Re: running rough when throttling up

I think you're on the right track to rebuild the carbs...but you may want to do a compression check and spark gap check (do not check if it sparks, check to see how far it will jump a gap) as well...they do not cost any money of you have the tools.

MAS

 

[tashasdaddy]

Re: running rough when throttling up

read the TOP SECRET FILE.