YZ400E

[yzhilly]

Well i'm back ,  The front wheel needed to move to the brake side to line up in the middle of the forks I moved the front rim across on the spokes to line it up a bit better, still not dead center but will do for a test this weekend. the forum looks great .

[yzhilly]

Well here it is again . I changed the jetting from a 310 main to 390 and the pilot to a 50 dont know what size it was but it was a lot smaller than the 50 and it,s seems to run a lot better .Any tips on running it in ?.

[Hoony]

the 400 is looking good for the Viper debut Hilly.

[Lozza]

Hilly this is the only way to run pistons in.

I won't tell you my  'top secret' short cut, but the best way is 3 lots of 5-10min runs with about 20mins in between each run.As the operating temp gets up the piston swells to a point where it grows no more.You want to to this gradually.
Start bike and tootle around with a high gear and a lot of throttle but not a lot of revs. Stop let bike cool down until you can keep you bare hand on the head for some time.
Next
Start bike ride through gears accellerating up to 2/3 throttle and go back down through gears.NO CONSTANT THROTTLE.Stop bike let cool down.
Next.
Last one is go for the doctor and rev it hard through each gear and back down again.Stop let cool down

Job done.
HTH

[yzhilly]

Thanks lozza i will run her in on saturday ,yeh hoony i put my  numbers on tonight  she looks shit hot so that one is in the rack i just got to fix some kids bikes before saturday, Has anyone had a problem with YZ80K kickstarter not engaging, it gets to a point where you have to move it by hand to get one full kick and the next one wont engage again. I 've had it apart a couple of times and it looks ok and doesnt slip when its opened up.??. any ideas my son is gonna have trouble pushstarting it when the track is a foot deep in mud !.

[yzhilly]

Help !!! I took the YZ and the kids out today the track was a foot deep and difficult ,So i spent all morning picking up kids lining them up with the track again and getting out of the way of the roost it was good laugh ,no injuries but some awesome stacks and saves there was 71 future vmx ers out there today. But the YZ has got me worried i ran it at 25 to 1 with my normal castrol 2T, i ran it up as best i could ,airscrew 1 1/2 out ,needle clip ,started in the middle, moved to bottom clip, still lean grey plug ran shithouse, moved needle to 2 from bottom, airscrew 1 1/4 out, run better midrange plug still grey, no smoke . ? i would have thought goin from a 310 main to a 390 any needle clip moves would richen a lot .i want to blow some smoke out  the back and go from there but i cant get any what am i missing ?.

[Lozza]

Grey equals death.
Start at the high jet and work your way down.A 38mm carb will run about 350-360main and a 36 about a 300-320 main on a 400cc bike.

[yzhilly]

Can anyone give the float hieght specs for YZ400E and Timing specs and test procedure to Set timing any help would appreciated thanks

[Quicksilver]

Hilly. Just got txt mesage from YZ250H ( Tony ) his not registered on new forum yet. He said Float height is 18.1mm.

Hope that helps.

[yzhilly]

Thanks Quicky, tell YZ250H to pull his finger out . I,m going to strip the carby and start again ,I might even lift the head and check the bore just to ease my mind as will only have saturday to get it right before our viper debut.

[Quicksilver]

Not a worry mate. Happy to pass it on.
I think YZ250H can read forums but not post.. He'll see ya message..

So Tony. Get ya act together and register..

[YZ250H]

OK - I'm back in !!!     You blokes have got a bit of a head start on me though, so I'll have to get busy.

I think I have to head over to general discussion and check out a YZ80 and 125.  Hope you get the 400 sorted in time hilly.  I imagine there will be a few nervous moments before the big debut.
Cheers 

[yzhilly]

Good to see ya back on board YZ250H, Well i had a major setback last night i checked out the 400 and the piston had nipped up again so i cleaned up the bore with a light flapper wheel and gave the piston alight rub and it cleaned up ok so a bit dissappointing but no major damage and it,s back together but i think i have found my cause,this time i pulled the carby while the aircleaner was still in and twinair inner had been sucked out of place and was restricting the outlet and also not sealing from the outside world. So i have yamaha's last airfilter assembly in captivity speeding it's way to me and i will start over again, i checked the carby again ,float height specs and air passages all clear so i will see how it runs without the inner filter tonight if it doesn't run better i might have to ride the IT465 this weekend it's not finished either but i dont wont to blow up the YZ

[yzhilly]

Ye Ha i got the YZ400E running and it's running that rich it is blowing a thick plume of smoke when you crack the throttle mmm lovely.The vent tube in the bowl had a plastic tube pushed over it not sure why and it's not in the parts list but i think it was sealing the vent against the body of the carby anyway it's running good i will run her up tomorrow and see how it goes. i was feeling pretty good about getting the carby sorted and now the race meeting has been postponed due to weather conditions .I was goin to put one of them funny face things in here but there is not one to match.!!!

[YZ250H]

Sooo... What happened dude ??  Is she roosting up a storm or what ? 

I reckon that vent tube was probably put there by Mr Yamaha for a reason.  Did you take it off ??

Is it back to a reasonable fuel mix now and adjust the needle?  At least the meeting being postponed means the 400 will be there with bells on !!