All 2st Houston We Have a Problem, first 2hr desert ride..

Engine problem:

From riding the bike once it got home to hitting the dunes after running her in the 300 never had any top end power and no power hit.

Today on its first ride to the desert about 1hr into the ride we hit another problem:
When under acceleration from idle to full throttle, at approx half throttle the engine would make a louder higher pitch ringing noise (as if the exhaust had fallen off) and the power would not increase at all.
It was as if someone put their hand over the intake causing the engine to bog down in revs.
Not knowing much about 2T my first thoughts were:
1. Power band not set/working correctly
2. Reed Valve jaming
3. Air escaping the GForce reed valve join (as mentioned in another post by another rider)
4. Poor mix ratio of gasoline? 40/1 but I mixed the fuel and oil in the tank at the gas station.


The problem then became random and inconsistant. Sometimes it would run fine then it start to play up.

That noise is the power valve opening. It should start to pull hard then.

Thats got me worried. How can something so simple go so wrong :S

Jetting is the likely issue

Im going to contact the dealer in the morning to find out.
In the meantime I have just ordered a Keihin PWK carb from JD Jetting
Will also oreder the race head (as soon as I locate it)... can you help me with that Mr Motosports

My elevation is around 1-200 mtrs above sea level.
Temps of around 20-35 degrees C

If it is jetting why would it be incionsistant? is it the Mikuni? I wont stress too much until I try the Keihin out when it arrives , hopefully
by the end of this week coming

The jd jetting on your bike is waste of time, the 300's run way better with a CEL or a EEL
Kehin needle. If you are not riding in the woods with alot of elevation changes I would think the stock mikuni with the right main and the Husky "GAY" needle would be just fine IMO

Does your bike still have the throttle stop inside the slide ?

Throttle stop has been removed from what I could see when I opened her up. I pulled the cap off the top of the throttle body and there didnt seem to be any restrictions for the throttle slider to move completely to the top. The only plastic/nylon I did see inside was sitting way down inside the slider just below the point where the cable joins onto it.

I actually ordered the entire Keihin carb from JD website. Not many riders seem to be happy with the Mikuni.

Keihin carb

JD Red needle in leanest pos.

37,5 pilotjet

170 maínjet.

Stop teasing me... Im still waiting for the carb to arrive and if my dealer is organised they will have ordered the race head for me. Im going to be pissed if my bike isnt ready for next weekend but they say good things take time

Haha! Just a tip. Maybe 40 pilot instead. I think it will work quite well with this setup. Hmm, maybe i should order the head too...

The only place I could locate the head was from Australia but it said I had to go thru my local dealer :S Not sure if its available in the US or Europe (it should be)


The settings you have suggested, will they be suitable for my elevation and for desert riding?

I would at least take the Power Valve Cover off to take a look. I have had the PV clutch come apart on my 02 and the Bolt that holds the Top Actuating arm came loose on my 09. You don't have anything to loose by taking it off and looking except for peace of mine.

Yes good idea