400 rebuild am i forgeting anything

[enduro400rider]

im ordering parts for my 400 rebuild and these are the things im getting- new rings, gasket kit, new wrist pin, and new crank bearings. is there anything else i should replace while im at it? oh yeah and im getting it honed

[fastkid400]

Are u tearing the bottom end apart for the crank bearings? You will have to look at the piston and the rest to know FOR SURE what you need.

[400exrider707]

new cam chain from a CRF450 for cheap insurance.

[enduro400rider]

Originally posted by 400exrider707
new cam chain from a CRF450 for cheap insurance.

put a brand new timing chain in 3 months ago so it should be good. but it just started smokin about 3 weeks ago so i want to get that taken care of

There is a rubber O ring at the base of your cylinder that does not come with most kits. I had to put my entire rebuild on hold for nearly a week waiting for that stupid thing. Make sure you have that.:D

[bigvforcer]

Get a valve job done. I would at least put new valve stem seals in the thing. I wouldn't waste my time and rebuild without doing that. The parts are cheap and it will save a headache later.

[YZ400EX]

Originally posted by golfman400ex
There is a rubber O ring at the base of your cylinder that does not come with most kits. I had to put my entire rebuild on hold for nearly a week waiting for that stupid thing. Make sure you have that.:D

You dont even need the O-ring at the base of the cylinder..There is no reason to use one..

[gojk]

From what I have seen, if you are splitting the cases, replace the seal in the case where the output shaft goes through. That seems to start leaking pretty early in the quads life.

You dont even need the O-ring at the base of the cylinder..There is no reason to use one..
The O-ring at the base of the cylinder is a protective measure to ensure a good seal between the mating surfaces of the head and the case. For $2.50 I think it would be prudent to go ahead and trust the engineers at Honda and put the o-ring that they designed in its proper place when you do your rebuild. :o

[BLEEDRED]

The O-ring at the base of the cylinder is a protective measure to ensure a good seal between the mating surfaces of the head and the case.

Hum, the head and the case? I think you might have messed that up. I was under the impression that the O-ring was to keep oil from getting between the cylinder and sleeve. If oil gets in there it will change the way the cylinder dissipates heat and can be damaging. However, I know that I used a new O-ring on my 440 rebuild last year and when I tore it apart this year the O-ring was cracked/melted and hanging in the case. Apparently the O-ring can't take the heat for the 440. Bottom line, I would use it on a stock machine but not on a larger bore. If you need this O-ring send me a PM with your address and I will send you brand new one still in the packaging for free.

[cals400ex]

mickey dunlap told me to leave it out when i resleeved so i don't have one in either