400ex started smoking

[rwc0920]

my 400ex started smoking a little the other day. rode it around today and it smokes more. checked oil level it was way low so i topped it off. still smokes. does this mean i need new rings, or is there something else i should check first. i figure a compression test should tell me if the rings are leaking bad. any other suggestions?

[rcer450r]

Well it def. has something with your oil destributing throughout your engine so I would have it looked at.

[rwc0920]

ive got a manual coming, but would a compression test tell me if i need rings or not? im assuming the only way for the bike to burn oil is if it leaks past the rings?

[rcer450r]

Also usually if the smoke is black, it is oil. Ya and the only way your burning oil is a leak in the pan or in the past the rings.

[honda300EXtreme]

yea odds are your rings are going or your valve seals are going bad..

a compression or leakdown test should answer your question

[JOEX]

Originally posted by rcer450r
Also usually if the smoke is black, it is oil. Ya and the only way your burning oil is a leak in the pan or in the past the rings.
It's my understanding black smoke means too rich. Blue smoke means oil burning...

[xc_racer1]

Originally posted by JOEX
It's my understanding black smoke means too rich. Blue smoke means oil burning...


if its smoking blue and its not running chitty its more than likely either the valves or u need new rings. my bet is rings b/c mine was doing the same thing and thats what i needed

[JOEX]

Originally posted by xc_racer1
if its smoking blue and its not running chitty its more than likely either the valves or u need new rings. my bet is rings b/c mine was doing the same thing and thats what i needed
That could be...

I was just pointing out a difference of understanding from what rcer450r posted;)

[xc_racer1]

is it running ok or is it spitting and popping. if so its just jetting. easy fix. if its not that then my moneys still on valves or rings

[AtvMxRider]

Originally posted by JOEX
It's my understanding black smoke means too rich. Blue smoke means oil burning...



you're right

[rwc0920]

well smoke is blue, so definatly oil being burnt.


it runs fine, just pops a little when you let off from WOT probably due to jet size, but that will be addressed after i fix this oil burning problem.

so its either rings or valve seals? what is involved with a ring job or a valve seal job? i got the manual coming and plan on doing all the work at home. rings i have an idea, disassemble, replace rings, button up, good to go. never done anything with valve seals though.

[gcart2]

lol its the rings and seals. i blew mine up cuz of that. i ran it too long and sure enough the oil burnt out and there it went. change em befor u ride that thing again

[rwc0920]

so i have to change both the rings and seals? sorry for being an idiot, ive never messed with quads before. how much am i looking at in terms of parts costs. will there be any need for secondary machining or anything of that sort? any recommendations for brands or vendors? thanks for the help.

[nickk]

Valve Seals are only 5 bucks, I just got a quote on them yesterday from colby

[1965 honda]

you proubley need new seals and rings provided your piston and cylinder are in good shape:macho

[rwc0920]

alright so it doesnt sound like it will be too expensive of a job. piston and cylinder will be good if there are no visible scratches in either the cylinder wall or the piston correct?

who should i get the rings and seals from? what should the stock bore measure to? i will need to know this to determine whether or not the motor was bored by past owners right? any other things i need to look at before i order anything?


and whos colby?

[vett_09]

Well if it is the rings, you're probably going to need a little more work than just buying a ring kit and putting it on. Since your 400 is 5-6 years old, if it hasn't had a new top end at some point in time, you'll probably have to have work done to the sleeve. You don't necessarily need to have it bored, but at least honed. I'm sure if it's never been re-built in the past the sleeve is scored.
You're going to have to take the head off to get to the piston anyway, you might as well put in new valve seals while you have everything apart.

And if I remember correctly the stock piston size is 85mm. Can someone else confirm that?

[rwc0920]

alright that makes sense. not sure if the last owner ever rebuilt it or not. so i guess if its the stock bore then it should be machined. how much does this usually cost and do i have to find a machinest or can i bring it to the dealer?

if machining has to be done, would be just be better to put in a 416 kit if we were possibly planning to get it later? would rather not have to do things twice. eh the money pit opens

i guess ill just pull the piston out and measure everything and give it a good look over. and go from there.

[Metzroth]

As stated earlier, if your quad has never been rebuilt before you will most likely need to have your cylinder bored out and honed. If you were already planning to build a 416 later, I would probably just go ahead and do it now as the machine shop will not charge more to bore it an extra mm over. (87mm:416cc::86mm:406cc) I am in the process of building a 416 myself. My J.E. 416 10.8:1 Piston with rings and circlips from C&D was $120. A full gasket set will run you $40. You might want to consider replacing your cam chain if it has not been done before which i think for an HD cam chain was about $30-$40. Valve seals are $5. You will need exhaust gaskets which will run about $5. You should probably have your head cleaned up and a simple 3 angle valve job done. My machine shop charged $40 to bore my cylinder and $80 for the head work. I would consider getting a cam as well if i were you. When I bought my quad it already had a hotcam installed so I don't know how much they run. Probably a little more than $100. Hope this helps some.

[rwc0920]

thanks metz, that definatly helps alot. the prices were helpful, doenst seem that bad for parts. i was thinking about buying a cam too if i were going to do the 416. did you order a full kit or did you piece it together yourself?

[Metzroth]

I ordered all my parts separate and did alot of extra stuff. I ordered Kibblewhite Valves($30 ea.), Kibblewhite Titanium Valvesprings and Retainers($90), valve seals($5), the piston ($120), HD Cam Chain ($40), Cam Chain Tensioner ($60) which was the reason i started the rebuild, a gasket set ($40). So as you can see, I ended spending alot. You should also probably replace your pivot bearings and if your pivot bolt is bent, i would replace it too. If nothing else, just make sure you lubricate everything good. Basically, I would just call Colby @ C&D and tell him what you're doing and tell him you need everything to do it. It will take awhile to get all your parts, but his prices are pretty fair.

[rwc0920]

thanks, does colby have a website?

[Metzroth]

http://cdracingonline.com/
Or just request a quote in the forums on here. Post your thread here (http://www.exriders.com/vbb/forumdisplay.php?s=&forumid=36) .

[rwc0920]

thanks ill give him a shout.

ps. metz your mail box is full i tried to send you a pm

[Metzroth]

it's all cleaned out. Try again :)