choke & running problem

[biker_jay]

Hi all.

I think the bike is running rich, tried to lean it off but not made much of a difference, wondering if anyone had similar problem.
So, when i start the bike, i have to shut the choke off straight away otherwise it will cut out, tbh i dont really need the choke to start.
Secondly, when travelling along, top gear, mid revs, if i shut off then roll on to 1/4 throttle, the engine picks up then dies down then picks back up again. Plus i can just be riding along mid throttle and it feels like its hesitating.
My thoughts are that it is rich, anyone got any other thoughts?
I've just dropped the needle down one to try it out tomorrow, plus i have a k&n filter on atm.

Thanks, Jay.

[Kevtrx849]

In my opinion the use of the choke is the reason that most TRX's use oil. The rich mixture washes the bores. If you can get into a routine of starting the bike without it you'll be better off. Less plug fouling as a result too. I think your on the right track with the needle adjustment. Something else to try is the highest octane fuel available (no ethanol) to clean the system out and maybe use better quality spark plugs like iridium. The hesitation at cruising speed that your experiencing could also be a bit too much freeplay in your drive chain as well.

[ekoja]

Could it be the opposite, you are running lean,( or your bike is.)
I fitted a K&N Filter and after needles and tubes were fitted I found that the bike did much the same as you describe.
This was with aftermarket pipes.
Standard pipes had it running somewhat better, but still there was this hesitation at constant throttle settings.
Anyway my fettler said that it is running lean due to the K&N and he is going to fix it by raising the needles, or dropping them, car'nt remember, now

[M.V.]

Sounds like you've got two or more problems...

Your idle mixture is set by the idle screw, assuming standard jetting K&N filter, 2-2.5 turns out is where you should roughly be.

As for the rolling on the throttle problem, have a play around with your needle heights, unfortunately, it's just trial & error unless you take it to a dyno tuner. Could be rich or lean...

See here for some tips: (Have you checked your emulsiopn tubes for wear?)

http://www.factorypro.com/tech/tech_tun ... gines.html

I'm running a K&N filter with slip on cans, the TRX runs very rich standard, 142.5 main is stock, I've gone down to a 132.5 main & still slightly rich according to the dyno.

[biker_jay]

well ive turned the mixture screw out 1/2 turn and it runs now with the choke on when cold. going to have a run tomorrow to see if its any better mid throttle now ive dropped the needle.
jay

* half a turn out from standard that is, so 3 turns out.

[biker_jay]

Sorted the choke problem out now.
At some point i have put the two screws in the wrong place inside the float bowl.



'A' being the starter jet and 'B' being the retaining bolt for the spray tube.
Both the same thread and i had put them in the wrong way around. Explains the choke not working.

As for the mid throttle problems, we are certain that it is a problem with the digital timing, or possibly the TPS. Anyone had any problems with these before?
Cheers, Jay.

[Mincehead]

The TPS can be set up with a multi meter. Look in the downloads section at the manual section, shhhhh.

[biker_jay]

ta.

[fung]

TPS Adjustment.

1. Turn on the ignition.
2. Disconnect the TPS electrical connector.
3. Re-connect the TPS connector, (puts TPS and rev counter in test mode).
4. If the Rev counter shows 4000 rpm, TPS is set correctly.
5. If the rev counter shows any other value you'll need to loosen the TPS mounting screws and rotate the TPS assembly accordingly to achieve the 4000 rpm reading, then re-tighten the mounting screws.
6. To reset to normal rev counter mode, start the engine or turn off the main ignition switch.


cheers
fung

[M.V.]

Sorted the choke problem out now.
At some point i have put the two screws in the wrong place inside the float bowl.



'A' being the starter jet and 'B' being the retaining bolt for the spray tube.
Both the same thread and i had put them in the wrong way around. Explains the choke not working.

As for the mid throttle problems, we are certain that it is a problem with the digital timing, or possibly the TPS. Anyone had any problems with these before?
Cheers, Jay.

There's your problem!

Sort that out & see which problems (if any) remain.

[biker_jay]

I have checked the tps years ago, cant imagine it has moved. I'll check it and get the cdi checked. It does feel like the timing is retarding itself when it shouldnt be.
At least the choke problem is sorted, just need the throttle problem sorting. It pops and backfires when shutting the throttle off as you would expect when retarding the ignition. Confident it is that, just got to fix it.
Jay