OZ ATV :: The Australian ATV Forum

[insaneyfz450]

we did some creek crossings over the weekend and my mate has a trx400 and crossed over without any problems , but my yfz450 05 model kept stalling in the middle of the creek, water was half way above the engine area but not over the exhaust, now when i twist on the throttle pretty quickly is has a major dead spot, im thinking maybe its the carby ? it was hard to start when we got it out the water, would only start with the choke on and took a bit before it would idle/run reasonably smoothly, could anyone give me some advice and if need be if i should pull the carby off and get it serviced and re jet or something ?
pipe is standard with the baffle cap removed.

Any help would be heaps appreciated.

[bigjon]

Sounds like a typical case of your carb breather hose being submerged. If you regularly do deep water crossings route it up higher.

Have you re-jetted it after removing baffle?
Early YFZ's are notorious for being lean from the factory.
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[insaneyfz450]

i havent as yet , im not sure what to re jet it to so still on the back burner... was thinking on just putting the baffle plug back into the exhaust

[bigjon]

insaneyfz450 wrote:

was thinking on just putting the baffle plug back into the exhaust

Don't do that.

A good place to start is Main 168 & Pilot 45.
Your stock is 158 Main & 42 Pilot which is too lean.
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Don't close your eyes during the crash, you'll miss the best part

[insaneyfz450]

hey jon i went to yamaha this arvo to get the jets and they are telling me the standard for the main is 100 not 158 ?

should i just buy a dynojet kit maybe ?

thanks for your help buddy

[bigjon]

insaneyfz450 wrote:

hey jon i went to yamaha this arvo to get the jets and they are telling me the standard for the main is 100 not 158 ?

Page 2 - 9 of the YFZ450 Service Manual states Main Jet #158.
Needless to say I wouldn't take my quad into your dealer for a service, they don't sound like they know the faintest about jetting.

insaneyfz450 wrote:

should i just buy a dynojet kit maybe ?

Yes, or even a GYTR or JD jetting kit.

insaneyfz450 wrote:

thanks for your help buddy

Your welcome.
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[PeteW]

stock is definatly 158, I would recommend a 165 main and 45 pilot for stock pipe with the baffle out. JD kits come with all the main jets you could ever need and the 45 pilot as well as 2 needles. Dynojet kits are fine for some models but the jet sizes are different (as in don't relate to the Keihin sizes)

As for your river crossing issue, route both the top breathers into the airbox and you should be OK also make sure the drain on the airbox is clear. I've done over the seat river crossings on my old YFZ with no airbox lid and the exhaust completely under water with no drama's.

PM me if your interested in a JD kit as I have a YFZ one here at the moment.
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[insaneyfz450]

awesome , how much are the jd kits ? where abouts are you based ? otherwise i can shoot down to luke beechey tomorrow morning and grab a set there.

thanks heaps for your help pete.

its great to get so much help from everyone compared to the dirtbike scene where every one wants to keep secrets haha.

[bigjon]

insaneyfz450 wrote:

its great to get so much help from everyone compared to the dirtbike scene where every one wants to keep secrets haha.

This is a secret. Don't tell anyone were giving away free info
Knowledge is Power!
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Don't close your eyes during the crash, you'll miss the best part

[PeteW]

insaneyfz450 wrote:

awesome , how much are the jd kits ? where abouts are you based ? otherwise i can shoot down to luke beechey tomorrow morning and grab a set there. thanks heaps for your help pete. its great to get so much help from everyone compared to the dirtbike scene where every one wants to keep secrets haha.

I'm based in Melb, the JD kits are $145 which is more exe than most jetting kits but are worth it IMHO.
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[yogie]

PeteW wrote:

I'm based in Melb, the JD kits are $145 which is more exe than most jetting kits but are worth it IMHO.

Pete I watched you run straight across the top of the dargo river once you were going that fast, then MB actually passed you also on top of the dargo river. Maybe you should just tell him to go faster... Hows the bub and mum going at home ?
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[PeteW]

yogie wrote:

PeteW wrote: I'm based in Melb, the JD kits are $145 which is more exe than most jetting kits but are worth it IMHO. Pete I watched you run straight across the top of the dargo river once you were going that fast, then MB actually passed you also on top of the dargo river. Maybe you should just tell him to go faster... Hows the bub and mum going at home ?

Mum and Bub are doing fine, just starting to get into a bit of a routine.

On top of the water is definitely better but you can' t always guarantee you'll stay up there. best to be prepared for getting wet.
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