Jetting for new reeds and pipe

[Red&BlackAttack]

Hello, i'm new to this forum, and this is the first one i've ever joined before. i hope to learn alot and make a few friends along the way. i've got a red and black 03 yamaha blaster with a pro circuit platinum 2 pipe and a 304 silencer. its got stock jetting right now but in the next 2 or 3 months i plan to put a new v-force 3 reed valve in it and i belive i need/can re-jet. i have no idea where to really start with the jetting and am looking for advice, i have also never done any work on a fourwheeler before besides bolting up the new pipe so any help with exactly how to do the re-jetting will also be appreciated. Thank you in advance!

 

[Larry's Shee]

Welcome to BF !! First off don't ride until you jet it. There is a download manual on here. Real easy to do jets. Probably about 270 main

 

[blasty 95]

Rejet for sure mang or instead of vforces youll be needing a new top end

 

[Awk08]

you need to get at least a 270 main jet in that with that pipe on it, or you'll be asking "new top end needed" questions real soon

heres some homework for ya, pop quiz tomorrow, LOL !!!!
and welcome to the forum !!!!..............


the downloadable blaster bible (open, click "file" then "save as" to copy to your desktop or other folder you can easily find)
http://www.rydindirty.com/blastermanual.pdf

my own maintnence/troubleshooting tips.............
http://www.blasterforum.com/engine-1...tenance-30347/

jetting 101 ..................
http://www.blasterforum.com/do-yours...xplained-1625/

plug chops................
http://www.blasterforum.com/do-yours...ug-chop-38674/

leakdown test...............
http://www.blasterforum.com/do-yours...-tester-10663/
http://www.blasterforum.com/do-yours...wn-test-31464/

heres some pipe reveiws, you can see what others are running close to your elevation and pipe, to get you close on the jetting to start
http://www.blasterforum.com/engine-1...-review-23423/

how to compression test.......................
http://www.blasterforum.com/do-yours...on-test-44314/

 

[Braaaptor]

Welcome to the forum! Do a little reading around on here, and you'll see some good pics on how to take your carb apart for the re-jetting.

First off, I (as well as most of us on here) recommend removing and getting rid of your airbox lid. It will free up some HP and the engine will run better.

As for re-jetting, put in a # 290 main jet if you take the airbox lid off, or a # 260 if the lid stays on. Be sure to buy only genuine Mikuni jets to use.

I recommend installing a # 35 pilot jet as well, in place of the stock # 32.5. This mod is up to you. Not everyone does this. I feel the engine runs better with a 35 pilot with the airbox lid off and a pipe installed.

Be sure to re-jet before riding any more with your Pro Circuit pipe. If you don't re-jet, you run the risk of blowing up your engine's top end. This mod (jetting) is NOT optional.

Good luck! This is an easy mod once you gain a little knowledge of how to do it properly.

 

[Red&BlackAttack]

thanks for the welcome. so i should be looking at a 270 main jet and should i change my pilot or leave that?

 

[Awk08]

stock pilot i prefer

 

[Red&BlackAttack]

ok, so taking the air box lid off does make a big difference, and if i do so look at doing a 290 main, what difference exactly does that small bit of difference of the pilot jet do?

 

[Awk08]

in the "jetting 101" link i provided above is a good breakdown of all jetting, including the pilot, if it idles good and revs clean with the airscrew between .5 and 2 turns out, that pilot is tits,
if under .5 turns = smaller pilot, over 2 turns out = larger pilot
in my experience, at my elevation (1800-2500') the stock 32.5 pilot is good on all but the most modded, 240bbk blasters