Yoshimura Jetting Suggestions?

[Bennyboy400ex]

I'm purchasing a Yoshimura Comp full exhaust system and would like to know exactly what jetting changes I will need to make before hand. My carb has all of the stock settings and I want to know any changes in everything from main jets to pilot jets. I also don't want to remove the airbox lid, just modify the snorkel if nessecary. I dont have any intake, exhaust, or engine mods at all at this time (if it helps any). Any imput is much appreciated.

Thanks,
Ben

[cals400ex]

i would probably run a 152 to 158 keihin mainjet. this will depend on the temp you ride in along with the elevation. no one can tell you exactly what you need. jetting is trial and error. i would probally run a 40 pilot jet also.

prolly 2- 3 turns out on the air fuel mixture and maybe move the clip on ur neddle on pos. down.

[Bennyboy400ex]

Originally posted by Jingle
prolly 2- 3 turns out on the air fuel mixture and maybe move the clip on ur neddle on pos. down.

Are you sure thats all i need? No change in main jet or pilot jet?

Oh yeah i live in Florida, and for those who don't know, the highest point in FL is a whopping 80ft!:rolleyes:
So, my elevation is between 0-80ft.

[sandspanker]

:o look at the second post he said a 152-158 main jet a 40 or 42 pilot jet 2 too 3 turns out on the air screw.:huh

[James Parent]

try (below 3000 feet)
146dj
3rd clip on needle
2 1/4 turns on the air/fuel
make sure you have the adapter if you use dynojet, even though it fits anyway

I'm rejetting mine, just got a yoshimura slip on, FMF power bomb, K&N, droped a tooth on the front sproket, ITP Holeshot XC all around

i will post in a few days with exactly what jets i used and what did/didn't work

P.s. I live in NJ

james

u need to do what i mentioned in conjunction with a richer main jet.

[Bennyboy400ex]

Ok gotcha:cool:

[seven]

I am at 2500 ft and with just the baffle taken out of the stock exhaust and a K&N air filter with no lid I am running a 158 main and a 40 pilot with the stock setting for the air screw and it runs great.

[Bennyboy400ex]

Cool thanks!
I was just on the dynojet website and they have a huge assortment of jets. The have a lot of the same sizes but with different prefixes of DJ, SJ, YJ, and BJ. What do all of these mean and which should I choose?:confused:

[seven]

In my opinion its a waste of money to get the dyno jets. Just go down to your local honda shop and they will have what you need for 4$

[James Parent]

oh, get the BJ's you'll be happy you did

just go buy normal jets so u dont confuse urself and have to buy the adapter when u get up in richer mainjets.

[sandspanker]

:D I'm always happy to get a BJ:rolleyes: :D ;) :blah: :macho

[Bennyboy400ex]

Anyone have a website where I can order these "normal" jets you speak of?

go to ur dealer prolly be about 2 bux a main.

[Bennyboy400ex]

Ok everyone thanks for all the help. I think I'm going with a 155 main jet, 40 pilot jet, and mess with the needle and air/fuel mixture screw a bit. No one mentioned any airbox mods so I'm still a little in the dark as far as that. Any ideas?

[bigredfan]

hey jingle where is this magical dealer with the prices so cheap?I just picked up a pilot jet today and it set me back $15.00.I was rather shocked that they were so expensive when all I paid for mains was $5.00 a piece from HMF.One more thing I went with the #42 pilot jet from the dealer and it is about 3/16 longer than the factory installed #38 pilot and I wanted to know was this normal or did my dealer screw up again and give me the wrong part?
Thanks

[James Parent]

I was riding and a bolt fell out of my side fender at the track.. before something bad came of this i just took a break and went to my dealer for a replacement. It was really helpful to see the quad on the computer and able to zoom in on certain parts with everything numbered.. the guy was such a help and then said they had the part in stock.. Great.....

$4.95 plus tax.

Wow.. and I bought my quad there about 2 months earlier...

Some dealers are just like that i guess

[phebus]

Different size pilots are different lengths also. Perfectly normal.

[Bennyboy400ex]

So I shouldn't have to worry about the new pilot needle being longer, right?

Well i guess since i buy alot of things at my dealer and i know alot of them i walked in and they gave em a few and asked for a few more and he just said ill give u those for 2 bux a piece. U gotta build up a friendship gotta shoot the she it with em some times.

[cals400ex]

Originally posted by Bennyboy400ex
So I shouldn't have to worry about the new pilot needle being longer, right?


the longer pilot is normal.

[Bennyboy400ex]

Ok good, thanks.
Still no airbox mods mentioned, so I'm guessing I shouldn't do anything, unless anyone has suggestions.

[cals400ex]

airbox mods can make a little difference but it requires jetting. if you ride in dusty or wet conditions, i probably wouldn't do it.