Carb rebuild

[motorbreath]

I was wondering what everyone would recommend for a rebuild, im going for a bobber, soo... what size main jets, pilet jets, needles, sprockets to...

Thanks

 

[5twins]

Without giving the year of your carb set and a list of your mods, you can't possibly be given a correct answer.

 

[motorbreath]

its a 1981 xs650 and there really arnt any mods to it, i put some new POD airfilters on it thats about it.

 

[remmy1101]

What are you going to do with the exhaust?

 

[motorbreath]

im not sure yet, any advice on the exhaust? Im pretty new to bikes, im more of a car guy but i saw this bike and i wanted it

 

[Sundie]

a 1981 will have bs34's. Run them stock, just replacing the needle/needle jet with the canadian setup. Then tune from there if necessary, which it generally isn't.

 

[gggGary]

Cheap guys (me) bump the taper jets up with radioshack washers, works great even on stone stock bikes.

 

[remmy1101]

for the exhaust I carefully cut the outer chrome covering right above the baffle and slipped those puppies right off. Next I have to purchase some exhaust wrap and cover it all up simple and looks good.
if you do pod filters and exhaust i think you'll deff have to go up on the main jet. I just ordered the next 2 sizes up from stock. I think 137.5 and a 140 main jet. I wont be fine tuning for a while still at this point but thats the direction to go in.
I plan on also shimming the needle to raise it ive used this method before on another bike and it works great no need to spend the extra cash on new adjustable needles if you dont want to

 

[motorbreath]

So if i cut the exhaust of at the baffles ill have to go up on my main and pilot jets, and get adjustable needles? How exactly do you know what size to use for the jets and what needles to use, thats were im getting confused?

 

[oldskoolcarbs]

Cheap guys (me) bump the taper jets up with radioshack washers, works great even on stone stock bikes.

i was wondering if someone has shimmed the needles on these bs34s, i just sold a fellow a set of bs34 carbs,, he is running mikes xs air pods, chopped exhaust and pamco ignition with high output coil. I'm thinking 142.5 on the mains and the .017 shims

 

[remmy1101]

really the only way you can tell what jets you need is to put them in and run it and see how it feels.
obviously if you allow more air in (pod filters) and more are out (removing exhaust baffles) you'll need more fuel to accompany the air to keep the ratio right... right? so moving to a bigger jet is a good start.
When you buy a jet kit it comes with many different size jets you have to try them ride the bike and see what works best. You could dyno the bike to be sure but that costs to much so don't bother.
Jets are cheap they can be had from mikesxs.com for $6 a set i think? I ordered the next two sizes up but i might need to go even more then that.

 

[motorbreath]

Thanks man im starting to understand finally, so should i increase pilot jet sizes equivalent to main, like if i go up 2 main sizes should i go up 2 pilot sizes?

 

[remmy1101]

No thats not true some people never change there pilot jets. Its all in testing but you should try to look up a good how to jetting article and follow it. The most HP you'll ever gain from your bike is going to be from proper jetting no other mod will make it run better or faster

 

[motorbreath]

Thanks for taking the time to explain all this stuff

 

[oldskoolcarbs]

thanks also, a lot of good info