Taffy It's your fault !! :)

Not really, but while reading your jetting Q's

(for about the 4th time now) I decided to grind the throttle stop down.

While I had the carb out I saw easy access to the MJ. You know where I'm going next. I checked the plug. It was just sooty black like my chimney.

So I'm thinking mmmhhmmmm time to go lean.

And it was nice of Yamaha to send a 160 MJ with the purchase of the new bike :D

After installing the 160MJ (down from 165)

It was so much stronger over the entire power band. I say from about 1/4 up was just awesome

and off idle to 1/4 was a little better than stock.

However the Idle is high then it will go low(sometimes) Idle screw doesn't really help because

turning it down causes the pulsing to get worse and then will die.

Also Cold Start was EZ before - Choke and 2 squirts of APJ and maybe 2 -3 kicks would lite her up. Hot starts were terrible though.

Now the Choke doesn't seem to effect it at all.

To start now - leave throttle alone except to prime with APJ. It was always fire up very briefly the first kick, but if you twist throttle past idle it dies instantly. About 6 or 7 instances like this and it will idle but don't touch the throttle for about 20 seconds or it'll

die instantly. After idling 20 seconds drive around for about 5 min she'll sputter around a little (a lot like a cold 2 stroker) and then be ok.

Also hot starts are 1st kick now.

Should I raise the needle a little? I haven't checked the plug today but will tomorrow as i'm tired from the track tonite :D

The rest of the carb is stock like my signature shows.

I do think it could stand some inmprovement on the low end too.

Taffy? Mark?, JD?, Hick?

Anyone else feel like chiming in?

Thanks guys.


i think you've done something to your carb besides the change to MJ. have you put the little bit of plastic back in the floatbowl? what about seals or leaks? is the clip on nicely and square etc?

the 160MJ shouldn't have done all that to your bike.

just the opposite with the needle. lift it up one place. this will give you more fuel to move off with. the midrange will go back to how it was with a gradual improvement toward higher revs.

it tells you how far out your jetting is when you end up squirting raw fuel in etc. i can't help it if you get stuck halfway between all the different settings.

the DRR isn't a good needle for starting procedure.


Taffy - Thanks for your reply.

have you put the little bit of plastic back in the floatbowl? what about seals or leaks? is the clip on nicely and square etc?

I never had the carb apart just took the drain out of the float bowl and with a nut driver replaced the MJ. So I don't know about plastic in the bowl or the clip fitting.

Also made sure to fit the carb back into the boots properly, as I know that can be an issue at times. I will take some starting fluid and spray around the boots while it's running tonite see if there is indeed a leak. I will be surprised if there is one.

I figured the DRR wasn't a good clip but that's what came as stock.

I am trying to gather up "ALL" the part #'s for the EMM, DMM needles, the PAJ(Screw), the MAJ, PJ,

Starter Jet(??)

If I get all the #'s at once I'll hit SUDCO with all of them so I won't be making 20 phone calls :)

So far I have these #'s If anyone wants to add #'s to the list please do.

Do these fit the 2002 carb?

EKN is part #5jg-14916-en

ELN is part #5nl-14916-en

SUDCO the EMM is an off the shelf needle. N427OCEMM (017-261)

Searching gives me nothing on the jet part #/s themselves. Do I just tell SUDCO I need a 35 PJ for an 2002 FCR Khein(sp?) and they'll know what I need?



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