Turbo YZ

The problem is that the needle seat is pressed into the carb, and is not serviceable.

I don't think that a wise move in any case, since once on boost and running hard, the concern will be whether the standard needle seat is large enough to handle the demand.

i was lookin at the seat. im wondering if you could take out the screws in that bottom part of the carb and get to the backside of the seat and tap it or press it out. but then again i have yet to find a smaller needle and seat. i have been searching the net for hours now. no Keihin parts to be found. im now thinking of looking around at our shop and finding a mukuni carb that would fit....

If you remove the bottom segment of the body, you won't be able to get a gasket for it, and again, the seat is not a serviceable part after the '02 model year.

Sudco is your parts source.

did some looking on sudco's sight. couldnt find anthing i needed really. i wish i knew how the YFZ trubo guys make theirs work. all the guys i have talked to say mine should work. so something must be differnt. tomorrow im gonna be on the hunt for a makuni carb. i could order all the parts i needright out off WPS. unless you can tell me how to make my carb work grey!?:doh:

I would 86 that slide carb and get a diaphragm carb off a jet ski (they have replaceable inlet seats also if you need more fuel)

and are butterfly and shaft design not effected by pressure as much as the normally aspirated slide carbs are...and are available in sizes all the way up to 44 mm....

I would 86 that slide carb and get a diaphragm carb off a jet sky (they have replaceable inlet seats also if you need more fuel)

and are butterfly and shaft design not effected by pressure as much as the normally aspirated slide carbs are...and are available in sizes all the way up to 44 mm....

or a trottle body as earlier suggested...

Too bad the AMA won't let you race it. :snore:

Looks like fun! :doh:

i think this bike would a bit scarry on a track. i dont think the power would be to an advantage! the sand dunes is where its all at!

is it running yet or are you still having trouble with it

There are some differences between the quads carbs and ours, right? Get the quad carb and try it out.

I know you said there is no room under there for a pull-through turbo/carb setup, but I would bet there is. You might wanna reconsider this. You can make it fit somehow. It might be a little hard to start, but drop the girl in first and push her down a hill, I guarantee it would start.

If all else fails, rip the EFI setup off an 09 CRF and call it a day :doh:

yes, still having problems.

There are some differences between the quads carbs and ours, right? Get the quad carb and try it out.

I know you said there is no room under there for a pull-through turbo/carb setup, but I would bet there is. You might wanna reconsider this. You can make it fit somehow. It might be a little hard to start, but drop the girl in first and push her down a hill, I guarantee it would start.

If all else fails, rip the EFI setup off an 09 CRF and call it a day :doh:

if i went pull through the carb would be hanging out where my filter is at. dont sound like an option to me (neither does your starting method). and i think i would get the EFI off a YFZ 450R before a differnt brand. and the only differnt between the YFZ carb and the YZ carb is the side the throttle cables come off. the YFZ carb has the cables coming off the other side of the carb. that is the only difference. trust me, i spent hours and hours looking at yamaha's PartSmart diagrams at our shop.

ya dont switch brands, im still going to try the efi from the 450r

are you sure the carb does not run an AirCutValve (ACV) ? i know the WR's do and yfz's are closer to WR's than they are YZ's

if it has the yzf carb on it then there is no air cut valve. yz480 any update?

none. still not working. tyson racing is building needle and seats for pressure. we're having a hard time dealing with them but im going to try to get my hands on a needle and seat.

im sending my carb to tyson racing. tyson is somehow machining a smaller needle and seat. hope this fixes my problem

any news?

nothing really. i called tyson thursday last week and he said he would ship it back that friday. so i should have it soon. i did have a good talk with him. he let me in on alot of speed tricks but i think he is a pure drag-racer. some of the set-ups he was talking about... i dont think would hold up pulling a hill in the dunes. but we'll see

wish I had found this thread earlier.....I could help a lot with your build if you'll lend me your ear. I've been through all of what you're going through right now. It can be very frustrating!

There is just too much stuff to address here. I'll PM you my phone number, give me a call some time if you like.

hey UncleBob, got a vid of your turbo yz by any chance?

and to yz480doinwork seems like you found the best project i can imagine. :worthy:

but y would you need more power :lol: jk

oh ya good luck!

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