Carb jetting

[husker]

Having the GTR's carbs cleaned and checking the jet sizes it has 140 mains and 30 pilots. 130 and 22.5 are standard. Should I put it back together or order some standard sized jets to put in it. I'm at about 1200 feet above sea level.   Thanks.............Rod

[dcr]

I read elsewhere on this site that 140 was factory jet size and after initial break in they were swapped out for 130's if elevation permitted.

[hardy]

While they are apart, lap the fuel bowl faces to check they are flat...otherwise, you could find that when you put it all back together they still leak

From memory, I think mine also has 30 pilots, but won't be home until the weekend to check...

[slawsonb]

The 130s work fine at 3000 ft at my house (and up to 9000ft on my runs up the mountains), but power is down as you go up. Should probably stop half way up and  rejet to 120s, but Naaaaaaaahhhh...I will have to take a look at the pilots to be able to weigh in on that one.
...bert

[husker]

I think I will get the 130s to have on hand. The needles were set in the second groove probably in an effort to lean it out a little. and I will check the bowls to see if they are warped or not. Thanks...Rod

[hardy]

I thought I had written it down, but I hadn't. I'm pretty sure that the new jets I bought from RC were 30's.

Ry

[husker]

Thanks Ry I have only put a couple miles on it so far (tanks and cover are at the painter now) and my initial impression is it is running a little on the rich side. I did get the 130 mains but the 140s are still in it. Going the have my brother put some miles on it and see what he thinks as he knows more than me about such things.......Rod

[RebusCom]

Stock main is a 130.  140 was for break-in and was supposed to be changed out after break-in but this was often overlooked.   The biggest improvement you can make is to change out the pilot jet as it is way too rich.  I run a 22.5 instead of the stock 30.  It's kind of an odd size so you may have to settle for the more common 25 instead.  Particularly if you run a 25 I would also lower the slide needle (raise the clip) one notch from center.  With this jetting you'll make a lot more power and it will run smoother.

Scott
http://www.bridgestonemotorcycle.com/

[steve]

Scott,
I'd be interested to know where you can buy 22.5 pilot jets please? I've contacted Sudco and they are available and likewise, I can also buy them here in the UK. However, Sudco have confirmed that the size they sell are 5mm x 0.8 pitch thread but I'm not sure if this thread will fit as the Mikuni carbs on Bridgestones used the pre ISO thread, so could be a 0.9 pitch.

Any idea what the correct pitch is? Thanks,

Steve

[husker]

I bought 25s from a Yamaha dealer and they screwed in OK.

[husker]

Please disregard my last post. They screwed in and maybe the 25s I got are .9 pitch but I just compared the jets I took out to a new 5mm  .8 and the threads don't match up...Rod

[hardy]

Hey Rod

Did you have any luck sourcing the correct thread smaller jets?

[husker]

I haven't done anything more with the carbs. I have wondered if since there the length of the threaded area isn't very long if I screwed in a .8 into a .9 thread. I plan on removing the carbs again to drop the float level a little more and will check it out then...Rod

[davis]

Try Sudco #004-005 #22.5 Pilot Jet. They fit my carbs. Also, Sudco #004086 for the #130 Main Jet. Sudco has an extensive series for both these jets.

Hope this helps - Bob