Author Topic: yz400e Jetting  (Read 2841 times)

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Offline jake57

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yz400e Jetting
« on: June 23, 2013, 12:29:52 pm »
now i can start the f&^%$#@g thing i have a problem with the jetting.
it has standard jetting
38mm Mikuni
main 370
Needle jet Q-0
pilot 60
needle 6f-16
standard pipe
DG silencer
i had this problem before i changed electrics
once started it will idle , it will not rev , turn the fuel off when it starts to run out it revs ok
thanks jake

Offline motomaniac

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Re: yz400e Jetting
« Reply #1 on: June 23, 2013, 12:54:28 pm »
check the float level.

Offline oldyzman

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Re: yz400e Jetting
« Reply #2 on: June 23, 2013, 01:23:04 pm »
Yep like moto said, Check your float level, or check the needle for excessive wear...
I have a soft spot japanese mxers with aluminium tanks. Two stroke classic Dirt Track...

Offline ARN

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Re: yz400e Jetting
« Reply #3 on: June 23, 2013, 02:59:59 pm »
if float level is ok as it isn't running out of over flows ,they are miles to rich standard ,try 50 pilot I am running 45 and 3 plus slide (you can file yours) try that

Offline TT5 Matt

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Re: yz400e Jetting
« Reply #4 on: June 23, 2013, 03:33:08 pm »
also check/replace the needle jet coz they DO wear out

Offline jake57

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Re: yz400e Jetting
« Reply #5 on: June 23, 2013, 03:40:55 pm »
thanks
new carbi , jets &needle
float level ok
3 slide
tried 45 pilot still the same

Offline firko

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Re: yz400e Jetting
« Reply #6 on: June 23, 2013, 03:56:53 pm »
Don't tell me it's still giving you shit Jake? Has Phippsy had a look at it?
'68 Yamaha DT1 enduro, '69 Yamaha 'DT1 from Hell' '69 DT1'Dunger from Hell, '69 Cheney Yamaha 360, 70 Maico 350 (2 off), '68 Hindall Ducati 250, Hindall RT2MX, Hindall YZ250a , Cycle Factory RT2MX flat tracker, Yamaha 1T250J, Maico 250 trials, '71, Boyd and Stellings TM400, Shell OW72,750 Yamaha

Offline TT5 Matt

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Re: yz400e Jetting
« Reply #7 on: June 23, 2013, 04:44:11 pm »
ok the jetting you have stated is it std yz400e jetting or what came with a 38mm off the shelf carb?
know anyone with a good running 400d/e?maybe borrow their carb to see if it cleans up your carb problems then copy it if it works ;)

Offline jake57

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Re: yz400e Jetting
« Reply #8 on: June 23, 2013, 05:07:42 pm »
matt it is standard yz jetting
firko yes it is still playing up,no phippsy has not looked at it
 

Offline ARN

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Re: yz400e Jetting
« Reply #9 on: June 23, 2013, 06:17:59 pm »
local bike shop had a yz250d which wouldn't rev out they rebuilt it and still had problem ,he lent a set of electrics of mine still no good ended up being a blocked exhaust or muffler.

Offline John Orchard

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Re: yz400e Jetting
« Reply #10 on: June 23, 2013, 07:56:14 pm »
How old is the needle jet?  Had the same problem with my KX, it was a worn needle jet.
Johnny O - Tahition_Red factory rider.

Offline motomaniac

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Re: yz400e Jetting
« Reply #11 on: June 23, 2013, 08:07:50 pm »
if you have the old carb try that.the new carbs are different and you will need to play around with the jetting ie original jetting spec wont necessarily work in a new mikuni.

Offline jake57

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Re: yz400e Jetting
« Reply #12 on: June 23, 2013, 09:17:12 pm »
ARN  i will check pipe & muffler
John  needle jet is new
moto had same problem with old carby
thanks for your nelp so far.  have work commitments this week will try again on the weekend