Carb basics ..

[aNiMaL]

OK, this is not really bandit related, but could be i supose.

What i need to know is .

If you was to put a bigger carb on a bike, but used the same sized mains/pilot jets .
Would this still work , or what adverse affects would it cause.

Reasoning behind this question ......

My son has just hit 16, so in my infinate wisdom ( been out of biking for 20 years ) , I got him a cheep little Suzuki TS50x.
Thought its gotta be better for he's large lump, than one of these twist n go things i always hear him slagging off.

Turns out there highly restricted, both ends of the pipe, carb, gearing , barrels  ...

Now that ive done some reading up, the only real way forward for more then 30mph is changing most of the above .
Big bore kit 47mm piston 70cc ( which would make it illigal for him to ride ).
Big one exhaust ( tails ok, but front pipe getting hard to find ).
A 21mm or even a 24mm carb ( which would work better with the first 2 items ).but for now, down jetted ?
and going up or down 2 teeth on either the back or front sprocket ( cant remember the correct one but have writen it down somewere ,lol ).

So ,i have read that people have used both the mitaka 21mm and 24 or 25mm with the 47mm big bore. they normaly say they have pipe too.
but they never mention the jet sizes, wether they up or down them to compensate.



was thinking about just getting the carb now, and downjetting , but is it just gonna keep flooding ,
Has anyone ever swopped there normal carb for a bigger one, just to see what would happen, and still had the bike running after ?

just one of many  oddball questions that run through my mind some times.

thanks for reading

Jay

[Chris H]

Hi Jay,
If the carb kit is from a random bike then you may need to change the jets but if its for the TS then the main jet supplied will be close. Using basic mechanics if you fit a larger carb and flow more air-giving more power-then the jet would be larger than original as more power=more fuel. Not sure what restriction would be in the rear of the pipe- maybe the tail pipe its self but they usually have washer in the front (by the exhaust port) that can easily be removed. Other retrictions can be in the reedvalve (if fitted) so if this can be opened up or the reed stops bent or even removed and low comp cylinder head- the big bore kits give more compression due to the larger bore.