pro circuit pipe re jetting

[patgas]

do i need to re jet my carb fitted pro circuit factory pipe ,will be riding sea level at about 10-20 c everything else is standard inc carb.oh and rebore 1.25 over

[lewisclan]

More than likely

[pimp559]

I was told to go up two sizes on your main for every 1 bore size you go up. I was wondering the same question you asked though. The donor 92 cr5 I got my motor out of had a pc pipe and silencer. When I cleaned the carb during my af build I took note that it had 170 main and 55 pilot which is stock/factory size on both. If you mod your air box you will definetly have to re jet but if you just add the pipe and ride in the same location you do with the pipe you have now you should be fine on that end but will need to go up on your main for the bigger bore.

[iggys-amsoil]

If the jetting is good now. Put the pipe on and see what it does. Most of the time the pipe manufacturer is correcting poor jetting from the factory.

Pimp - "I was told to go up two sizes on your main for every 1 bore size you go up."

That sounds like some bad info there. I could see it if the motor was ported and rebored. But in my case, porting, it was the needle in the 1/2-3/4 ranger in the needle that needed two sizes richer, from a Cxx to an Exx. The main stayed the same.

[lewisclan]

well I had to put in a 210 main last weekend I am also using E-- needel.
that was the bigest jet I have I orderd a 215 & 220 Ill put the 215 in there and see if it starts to fall on its face.

so using your ratio on bore size & jetting what has happend to my motor to where its sucking up a 210 main on VP110, and I think its still a little lean Holy Crap

[LOVEMYCR500]

It looks like your porting and head are stock, so I would keep your 55 pilot, 170-172 main, and switch out the stock needle which is a CGJ and go to a DGJ in the middle and work your way from there, especially if you are riding in the dunes. The D series needles are richer all over the band, if you are rich in the 1/4 throttle range, go start going larger on the last letter on the needle, this will lean it up in that spot. I ran a 55 pilot, DGK-DGL needle in the middle clip postion and a 170-172 main with your setup but V-force reeds, K&N filter no lid, bored stock carb, and the head rechambered on 110 and I will still a bit on the fat side down low and pretty good on top in the dunes at sea level. This is my machine though, your's could be different. Read the jetting section that Bob did, it's a good thread to get started.

[pimp559]

If the jetting is good now. Put the pipe on and see what it does. Most of the time the pipe manufacturer is correcting poor jetting from the factory.

Pimp - "I was told to go up two sizes on your main for every 1 bore size you go up."

That sounds like some bad info there. I could see it if the motor was ported and rebored. But in my case, porting, it was the needle in the 1/2-3/4 ranger in the needle that needed two sizes richer, from a Cxx to an Exx. The main stayed the same.

A local reputable shop told me this when I got my jug bored. I should call back and ask if that is just for break in. It does seem logical that you would need a little more lube for a little more bore to me though.

[lewisclan]

Heck yeah if you change anything you will have to re-jet, infact the jetting mite not be on the money before you change anything. I dont think there is a bore it .020 go bigger on the main raito deal. every bike is unique