wont run for a period of time

[mftlln]

I just rebuilt the motor to my 400ex to a 416 I had to redo the bottom end also. The quad runs awesome but it gets hot and dies out then won't start but it still turns over. When it dies out it squeals then locks up I have no clue what is wrong can u have some help

[JOHNDOE83]

did you rejet it?

did you recheck the oil level?

what you described really isnt good:eek:

[300exBorg]

can you post a vid of it doing it by any chance?

[mftlln]

okay i just rebuilt the whole motor on my 400ex. the quad runs great but i can not ride it more than 10 min without the quad dying and not restarting when it died on me it made a squealing sound and the rear tires locked up. the gas tank was so hot that i could not touch it and the top end was smoking. this is the second time it happened to me i have done an oil change and checked the oil many times when i was ridding. i was told that the timing might be off checked it again and it was perfect. after it quit the first time i had to use starter fluid to start it and i was hard to get started but after i got it started it started right back up when i stopped to check the oil. it is not jetted.

i will try to get it restarted sometime soon and have some one take a video of me ridding or use the go pro


i hoped this helps

[Speed37]

Mabey your not usung the right oil? Cause it sounds like your top end is burning up? Or mabey the oil pump isnt working correctly? Pull the head and look at the cylinder and the piston. If ur oil levels are right, the oil isnt lubing the cylinder?

[mftlln]

i am running Honda oil 10w-40 and it has a new oil pump. how would i also be able to check the oil pump?

[hocman123]

DO NOT TURN IT BACK ON UNTILL U JET IT !!!!!!!!!!!!!!!!!!!!!!!

u are running it way crazy lean makeing it run super hot to the point that u locked up the piston. u allways need to rejet ur carb when u do about any proformance mods on the atv at all. the jets in it now is most likely 148 main when it should be around a 170.

i would be shocked if u didnt allready fry the rings and scored ur new bore and u end up haveing to rebuild the top end again

[dxcody]

Originally posted by hocman123
DO NOT TURN IT BACK ON UNTILL U JET IT !!!!!!!!!!!!!!!!!!!!!!!

u are running it way crazy lean makeing it run super hot to the point that u locked up the piston. u allways need to rejet ur carb when u do about any proformance mods on the atv at all. the jets in it now is most likely 148 main when it should be around a 170.

i would be shocked if u didnt allready fry the rings and scored ur new bore and u end up haveing to rebuild the top end again

x2

Been there done that!

Its lean as hell.

Hate to tell you but the damage is probably done.

I didnt wanna hear it either but you will def wanna take everything back apart, and check it all out. You probably have big scorches in your bore now.

This sounds like a very expensive learning experience.

[CJM]

Im betting you also need to adjust the valves, did you dot hat as well?

[mftlln]

Are the jets the 2 in the bottom of the carb

[CJM]

Originally posted by mftlln
Are the jets the 2 in the bottom of the carb

Yes. You need a 42 pilot and start with a 180 main jet. You will need main jets from 180-160 in increments of 2.

You can buy the jets at your local dealer or online at www.jetsrus.com For info on how to jet the quad I suggest you click the link in my signature which has links that will take you to quite a few jetting threads.

BUT its possible you may have already fried everything.

[mftlln]

Originally posted by CJM
Yes. You need a 42 pilot and start with a 180 main jet. You will need main jets from 180-160 in increments of 2.

You can buy the jets at your local dealer or online at www.jetsrus.com For info on how to jet the quad I suggest you click the link in my signature which has links that will take you to quite a few jetting threads.

BUT its possible you may have already fried everything.

thanks for the help i can get jets for3.50 a jet at honda so i will get them sometime this week and let you know how it goes

[dxcody]

Originally posted by mftlln
thanks for the help i can get jets for3.50 a jet at honda so i will get them sometime this week and let you know how it goes

Before you start jetting it, buy a top end gasket kit and take your top end back apart and check it out.

It does you no good to jet it if your top end is fried already.

[mftlln]

i took apart the carb and its got a 148 and 38 jet in it so what should i get. i was thinking 180 and 42

[CJM]

180 will be too much, but its a good idea to start there and keep going down till you get it right. Read the jetting faqs in my sticky to figure it out.

[mftlln]

i bought a 170 main and a 40 slow and the wont idle now and backfires or pops when being reved

[JOHNDOE83]

Its still to lean.

Try to turn your a/f screw out to 3.5 turns, If it still pops and backfires youll need the 42 pilot/slow jett.

You may need the 180 main jet also, possibly 190.

[mftlln]

Originally posted by JOHNDOE83
Its still to lean.

Try to turn your a/f screw out to 3.5 turns, If it still pops and backfires youll need the 42 pilot/slow jett.

You may need the 180 main jet also, possibly 190.

is that the screw on the out side of the carb

[mftlln]

Originally posted by JOHNDOE83
Its still to lean.

Try to turn your a/f screw out to 3.5 turns, If it still pops and backfires youll need the 42 pilot/slow jett.

You may need the 180 main jet also, possibly 190.

is that the screw on the out side of the carb

[CJM]

Originally posted by mftlln
is that the screw on the out side of the carb

Underside of the carb next to the bracket for the idle screw.

[2001400exrida]

no offense but how does somebody invest in a motor like this and completely forget the most important part.

You can do all the motor mods int he world but if you don't jet it properly you aren't taking advantage of all the motor mods.

[mftlln]

Originally posted by 2001400exrida
no offense but how does somebody invest in a motor like this and completely forget the most important part.

You can do all the motor mods int he world but if you don't jet it properly you aren't taking advantage of all the motor mods.

yea i just learned this it was my 1st rebuild and i am only 15 so it is a learning experience.

[dxcody]

Originally posted by mftlln
yea i just learned this it was my 1st rebuild and i am only 15 so it is a learning experience.

Just so you know, dont feel bad.

I was 15 and got my 400ex, 416 11:1 and a full exhaust. And i ran stock jetting and fried it.

Lol At least you now know.

[mftlln]

yea when i bought mine i got it in a basket back march and now i am just getting it going