[sedlmeier101]

I just bought the TBBK and set it in my 50 yesterday and for some reason it wont run for shit when i use the big carb it came with.. but when i set the stock carb on it ran fine!? it has to be a problem with the carb, any one have this problem?

 

[Z]

Any time you install a bigger cylinder or modify the stock motor, you have to dial in the carb.



Is the motor running rich or lean?

Did you check the float height?

Is it running bad during WOT, or idle, or midrange?



Are you running the BBK and the race head, or just the BBK with the stock head?



What pipe are you running?



Please be specific here, as you are dealing with more than one variable.

 

[sedlmeier101]

Its not just running bad.. it wont run at all.. like it will start after about 10 kicks then it backfires horriable and quickly stalls out..

 

[sedlmeier101]

o yeah.. im running stock pipe.. and the stock head

 

[five0addict]

its the restriction of the head+carb, ive ben working on a 72. just got it running when we moved the clip in the carb down and ajusted the air.

 

[Jetster220]

Sounds more like Timing to me. Have you double checked your timing to make sure it is correct, and how about your valve clearances.

 

[sedlmeier101]

both timing and valves r fine belive me we checked it 3 times.. it has to be somthing w/ the carb.. im gunna try and figure it out today

 

[Jetster220]

How about the possibility of it sucking air. Just trying to give some ideas to check for.

 

[jsyi]

Sounds like timing to me as said above by someone. I know on mine i had the same problem and it turned out that the timing wasnt right even though I had it set right with little t lined up and the little hash mark and o right. I had to figit with it a couple times before it would run right.

 

[luma51]

I had a simaler problem awhile back and it was as simple as the overflow tube was pinched on the cylinder.Man it popping and backfiring like crazy.However I do agree it does sounds like the timing is off though.

 

[HBkev]

make sure when you set the valve clearence that the piston is at tdc. rotate the flywheel untill you feel play in the valves, then set the timing because it defintily sounds like the timing.

 

[Jetster220]

Take the carb apart and check it over. I just reread your first post and realized that you said it ran with the stock carb on. So take the new one and just take it apart and go through making sure everything is clean and together right and that none of the hoses are pinched when you put it on or anything. If none of that works, shoot Mike a email at TrailBikes and we will do everything he can to help you.

 

[Guest]

You just have to dial in the carb like Z said. Play with it until you can keep it running. Then dial it in until it runs good.