TE450 fouling plugs/over fuelling

Ever since I've had my TE450, it's fouled plugs within a short time. It also uses far too much fuel & leaves black carbon on my rear guard & indicator. My local dealer reckons the choke is half sticking on but I can see no evidence of that. I think the jets are too big but I haven't yet pulled the carb off to investigate. The valves are all new s/s & all else seems ok. Air filter is clean & fuel quality is 98 octane. I tried an iridium plug which lasted a little longer but still fouled. I'm getting 1 ride out of a plug. When I clean the plug it's ok for a little while but then starts flat spotting at cruising spead & down low. It eventually starts missing & backfiring & becomes hard to start. Carb is mikuni. Compression is good & motor burns no oil.

I'm going to pull the carb apart but was wondering, has anyone else had this issue? What are your thoughts?

Edited by Full-Throttle

With a Mikuni it's a 2004, right?

I'd suspect a high float level, leaking needle/seat, or a choke hanging up. If the carb overflows when not running, it's prob the needle/seat. I would take the choke cable/plunger assy out, check for smoothe plunger movement. You can also feel the spring preloading in a bit as you install it. Make sure the cable ends are seated in the holders properly. A dab of grease on the plunger is the way to go. Definately check the float height. I don't have a spec for you, reply with a year and maybe we can chase down the spec.

Does it seem to run/feel rich in general? Does it start right up cold without choke?

Yeah its an '04. It's not overflowing. Most of the time it starts without choke unless the weather is cold or if the plug is a bit fouled already.

I have the specs for it in the manual. It does seem like its running rich most of the time but not so much at high speed/high rpm.

It uses twice as much fuel as my worked KX250 2 stroke.

Pull the carb and report back. If there is an o-ring that seals the needle/seat into the carb body, suspect/check it also. Haven't had my carb off in eons can't remember!

I'm guessing that with all the fuel consumption, when you pull the sparkplug when it fouls, or just before, it is dry and blacksooty not wet/oiley?

Yeah dry & black is correct. There are no caked on deposits but just a thin crust of carbon. I'll pull the carb in the next week or so & post back. If you don't reply I'll PM you if that's ok?

No prob PM or here I'll try to help you.:thumbsup:

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