Carb re-jet

[bpdchief]

I asked DUPO earlier, but, am putting this out anyway.... if someone drilled holes in the muffler to try and make it sound like a bigger bike what do you think the chances are they re-jetted the carb? Since it sounded so much like a 250 with an exhaust leak, I had the holes welded over today. Now it smells maybe a little rich... since it comes lean from the factory - is this a problem?

[blaine]

Originally Posted by bpdchief

I asked DUPO earlier, but, am putting this out anyway.... if someone drilled holes in the muffler to try and make it sound like a bigger bike what do you think the chances are they re-jetted the carb? Since it sounded so much like a 250 with an exhaust leak, I had the holes welded over today. Now it smells maybe a little rich... since it comes lean from the factory - is this a problem?

Hard to say.I would try setting the idle mixture first.It's probably only a little rich at idle.You usually only need to do a rejet if you modify the intake or air filter.
:cool:

[alantf]

Originally Posted by bpdchief

Now it smells maybe a little rich... since it comes lean from the factory - is this a problem?

European models - like mine - are set up richer anyway. It's just the American bikes that are lean. I'd just see how it goes for a few days before stripping the carb.

[Road_Clam]

Originally Posted by alantf

European models - like mine - are set up richer anyway. It's just the American bikes that are lean. I'd just see how it goes for a few days before stripping the carb.

A combustion engine is simply an "air pump". So the more air that you let in, then more air you need to let out.When it comes to performance "gains", if you only improve the flow at one end of the process, your most likely encountering a "bottleneck" at the other end of the process. So where you have "uncorked" the exhaust for more "noise" which is also some added flow, the fact that you have a stock airbox setup is most likely negating any true flow gains. If there is no added air flow, there is no need for additional richer jetting. This is especially true if your euro spec bikes come with richer jetting. Our USA based bikes always come jetted lean they barely run decent especialy if we ride in colder temps.

[tsmall]

bpdchief, It may have been re-jetted but the only way to know for sure is to look. Take the tank off, 2 - 10 mm bolts and the fuel line and the carb vacuum line, and you can loosen the carb clamps. You can then just turn the carb sideways to take the bowl off. Just BE CAREFUL! Use a good Phillips head and be careful not to strip the screw heads up (I got that Tee shirt!). If you have your bike in the living room, make sure you have something to catch the fuel in the bowl! You can look at the number on the main jet. And you don’t have to monster tighten the screws back up.