2009 PitsterPro XTR 250 Enduro need carburator adjustment!

[bomorceau]

Follow the link to view how my engine is running.....description of what I did on my bike in the description of this video. Thank you!

[mizke]

dont do quick revs slowly give it more throttle to figure out which area of throttle the problem is..

idle -1/8
1/8-3/4
3/4 - full throttle

figuring out which end of the throttle range is causing the problem will tell which jet needs to get messed with

my quad did that quick fast rapid back fire sound, turned out i needed to lower my needle down one notch.. but that was after putting a fmf pipe on it.

[Weldangrind]

Welcome!

Since the response improved with partial choke, I'm inclined to believe
that the engine wants more fuel. You referenced trying a bigger jet than what's in there now, and you also said that you tried different clip set points; what the reader doesn't know is what the order of events was.

Before doing anything else, move the clip down one notch and repeat the test. Please let us know what happens, and try to repeat the same conditions (hot engine).

[mizke]

Originally Posted by Weldangrind

Welcome!

Since the response improved with partial choke, I'm inclined to believe
that the engine wants more fuel.

thats what i was thinking but was not sure..

[bomorceau]

From 1/4 to full throttle, it run perfectly. No back fire or hesitation.
1- I changed my pilot jet for a larger size. (40)
2- I moved the clip down one notch from the middle.
3- I changed my pilot jet for a larger size. (42)
4- I switch the 42 pilot jet to 40 pilot jet.
5- I changed my main jet for a larger size. (110)
6- I moved the clip up one notch from the middle.

Current set up is: Main jet 110, Pilot jet 40, Needle Clip up one notch from the middle.

I wish it help you to fix my problems.

I'll try to move the clip down one notch from the middle and I'll let you know the result. Thank you for help!

[mizke]

just incase your not 100% on what each jet does here is a break down of jetting a carb

http://www.atvriders.com/articles/jetting.html

[Wild_Alaskan]

without a pumper carb most bikes will do that if the throttle is whacked open fast enough. you may be able to improve it through jetting but don't expect it to go away 100%

[bomorceau]

I tried it in the same conditions. First, I moved the clip down one notch. Result: Nothing different! Second, I moved the clip down two notchs. Result: Nothing different! I moved it up to the previous set-up......in the middle of the needle.

Originally Posted by Weldangrind

Before doing anything else, move the clip down one notch and repeat the test. Please let us know what happens, and try to repeat the same conditions (hot engine).

[mizke]

put the stock pilot jet back in, and then try again with the needle settings..

if it ran with the stock jetting and carb setup, the only thing to do is to return it to stock and make one adjustment at a time..

[bomorceau]

Tomorrow, I'll put the stock pilot (38) and main (105) jets back in because my bike can run with it.

Step one: I'll move the clip down one notch.

At each adjustment, I'll do a new video to help you to compare with the previous video. I'll send you the link.

Thank you!

Originally Posted by mizke

put the stock pilot jet back in, and then try again with the needle settings..

if it ran with the stock jetting and carb setup, the only thing to do is to return it to stock and make one adjustment at a time..

[Wild_Alaskan]

the idle screw makes a big difference also try adjusting it to different settings

[culcune]

Have you tried contacting the Canadian or US Pitster headquarters? Pitster's main site has a forum, also.

[bomorceau]

Yes, I tried contacting both. They always said: Refer to bla bla bla set-up guide! About the Pitster Forum, I sent about 3 or 4 e-mail to register and I'ved never receive any reply!.

Originally Posted by culcune

Have you tried contacting the Canadian or US Pitster headquarters? Pitster's main site has a forum, also.

[mizke]

Originally Posted by bomorceau

Tomorrow, I'll put the stock pilot (38) and main (105) jets back in because my bike can run with it.

Step one: I'll move the clip down one notch.

At each adjustment, I'll do a new video to help you to compare with the previous video. I'll send you the link.

Thank you!

its all good man, tuning a carb can be tricky. i just recently went through this and it took me a few days to fix.. just keep in mind if you do a aftermarket pipe and/or intake, you will need to up the jetting. but most times the main is the only jet that needs messed with.

once its all back to stock, do the test for the main jet. 20 to 30 seconds full throttle while riding the bike. then kill the motor while at full throttle, DO NOT let the motor return to idle before killing it. just keep the clutch lever squeezed in and come to a stop.. check the plug, if its black you are to rich, if its whiteish you are too lean. you want the plug to have a brownish tanish coloration to it. but the motor will handle a slightly rich mixture better then it will a lean mixture.. too lean for to long and you will have a 250cc paper weight. running way to rich can lead to the same thing, but a slightly rich setting is ok..

[bones33]

I can't see the video here at work but is the engine cold or hot? If cold does it hesitate less when hot?

Also ensure the float level is set correct. Incorrect float levels can do wierd things. It's a no-cost adjustment, usually.

Refer to the manual to check/adjust and/or...

Use a clear hose (like the vent hose from the battery) on the drain from the carb, hold it up to the carb while the bike is perfectly vertical, open the carb drain screw. Make sure the gas is on to the carb.