Hi,

Wondering if anyone can help identify next steps. Recently bought an RTL which I still can't get to run properly - main symptom is on 75%+ throttle it starts to fluff as if starved of some fuel (or air I suppose) and smokes a bit. Also pops and bangs a bit on the overrun .

I have replaced floats, carbs o-ring kit, and latterly a new needle jet all with Honda OEM parts, but no luck. I haven't put the needle jet seat replacement in because I can't work out how to get at it - does it just press out from below?

Have replaced the plug with a new correct one.

Grateful of any other advice?

Thanks

Is the smoke black or blueish white?

75%+ should be main jet territory.

NEEDLE JET SEAT WILL TAP OUT FROM BELOW (TOWARDS SCREW ON CARB TOP) WITH SUITABLE SIZED PUNCH OR OLD DRILL BIT

Yes I thought that too - thats what the manual says, 75-100% is main jet, but as Jim at Gordon Farley told me there's not that much that can go wrong with the main jet and it looks ok. So that makes me think it might be the float level if it is in fact anything to do with the carb.

Mcman the smoke is black but it's not continuous, only when this fluffing starts. Do we think it could be valve related? There's no noise to indicate loose camchain.

hi float level should be 24 mm

Is the main jet the correct size? Could it have been drilled out to a larger size? Could you have somthing in the air box that becomes a restriction at high air flows?

Is the issue above 75% under load? I once had a bike that ran fine and picked up rpm well with no load but would miss under moderate to heavy load. It turned out to be a wire under the flywheel with worn insulation. Underload, there was less resistance to jump from wire to ground than there was to spark the plug.