xr650l backfire kubiak???

[travmanzz]

hey getting my xr together and it dosent want to start and and backfires like a 12 guage shotgun. I have the air cleaner off and notice when i pull the throttle the carb sleeve hardly moves too.I was thinking maybe the timing chain jumped it has 2250 miles i bought it new but i didnt adjust the chain yet.HELP help

[travmanzz]

i took all the smog pump junk off and block the lines off on the carb like thread on thumper talk shows
stock exhaust and air filter and jets

[kubiak]

i think your timing chain should be ok and i think the stock cv carb sleeve doesnt open with the cable all the way.it uses vacuum to lift the slide.sounds like a spark problem maybe?what have you done to the motor so far?

[travmanzz]

the motor is all stock i check the sparks is good.I thinking something is messed up in the carb going to check it out and clean the jets.I havent heard much on 650l timing jumping so i dont think thats the problem. seems like fuel.I can turn the fuel petcock off and then crank it over then it will attempt to fire but not start.I think something may be broke in the carb causing to much fuel delivery. have you done the DAVES carbs mods at all? if so how does that perform,once again thank you for your advice.

[towman]

The L backfires a lot on decel, with the smog pump and the factory jetting, so if you have the smog stuff off already, look into the the carb for sure. Dave's mod is a must for all XRLs anyway:
http://www.4strokes.com/tech/honda/xr650lcarbmods/

Complete Dave's mod first and plan to rejet depending on the altitude you are using the bike the most.

[kubiak]

the motor is all stock i check the sparks is good.I thinking something is messed up in the carb going to check it out and clean the jets.I havent heard much on 650l timing jumping so i dont think thats the problem. seems like fuel.I can turn the fuel petcock off and then crank it over then it will attempt to fire but not start.I think something may be broke in the carb causing to much fuel delivery. have you done the DAVES carbs mods at all? if so how does that perform,once again thank you for your advice.

yea on my xr i went with a 55 pilot,158 main,slide drilled 5/32,needle shimmed .027.it runs perfect with that setup for me.

[travmanzz]

I not sure what to use for jets with my new air box thinking 165 Iam going to to install a header and aftermarket exhaust with a K&N in this airbox.I took the carb off and and clean the jets i noticed the pilot was clogged up so there soaking in carb clean and going to order jets as soon i figure out what to use.

[travmanzz]

I cleaned the carb pilot and main jet

daves carb mods idle air 2.5 turns out
drill sleeve 5/32 outside holes
.26 washer under needle

stock jets* couldnt find new ones ,jets are us have some coming
I checked the spark, good

[chakad]

If you are trying to start it with stock jets and no filter. Good luck. I couldn't get mine to start without the airbox hooked up and stock jets.

Larger jets and It was good to go.