yamaha t-8 problem

[bob]

I have a yamaha t-8 that runs bad at low to medium rpm. It coughs and hesitates,then when I get it to high rpm it runs fine. It does this intermittently. I changed the spark plugs, changed the fuel filter, rebuilt the carb, changed the bulb and fuel line. Does anybody have any suggestion on what it could be?

Thanks,

Bob

[fishkisser]

Is your choke opening up completely ?

[bob]

I checked out the choke. It looks like it is working properly.

[fishkisser]

Are you running this off your main tank or a portable ?
It sounds like there might be water in the fuel or a partly plugged screen on the pickup tube in the portable tank ...
If being run off the main tank I have seen this happen when the check valve starts to go out at the water separating filter ...

[bob]

I put a new water separator filter in and I checked my big motors filter to see if the red check ring was floating and it is not.

Bob

[fishkisser]

How old is your motor ? It might be that your thermostat is stuck open and the motor takes a long time to warm up to correct operating temperature ...
Otherwise check for corrosion on the wiring for the motor and the plug wires ,coil ,ect ...

[Dinikin]

I would try a $ 6 Seafoam treatment before tearing it UP.
Also does it have fuel pump, try checking that.
Also you can install fuel pressure gauge on the line to see if the pressure drops during that hickup. They are not that expensive.

[StickFish]

Decarbon will help, but your problem is mainly in the low idle of the carb. Mine was doing exactly the same thing, tried the shock treatment of seafoam - didn't help much. North River rebuilt the carb and confirmed that there was some debris in the carb. Hope that helps

[No Bail]

I had the same problem and Brown's Landing did a quick and good job getting my gunk out. It was the smallest bit of stuff in the idle jet.

[wsmahan]

I agree with the carb needing another cleaning. Small peice of trash in there causing issues.
Wes

[Johnny B Bad]

My friend is having the same problem just today while we fished. I talked to Perf Marine and they feel also that the carb is gunked up. They recommended using fuel stabilizer regularly and to run up the kicker occasionally to heat it up and clear things out. Going in to P.M. Monday. John

[Lepper]

Had the same issues. Was a little piece of dirt in the carb blocking a jet. I'd reclean the carb, make sure you blow it all out really well.

[Green Giant]

I had a similar issue that Browns landing did a good job fixin. They claimed it has gunk in the carb due to bad gas. Recommended running stabil or chevron techron fuel system cleaner in it regularly (not just for winter storage)