PDA

View Full Version : 400ex Head/Cylinder Bolts Help!



skatrdude20
11-01-2007, 07:39 PM
Alright guys, heres the deal. I got a 400ex cylinder and head here and I got a problem. I get my whole engine built, timed, sittin pretty (Mind you this is my first 4-stroke engine build by myself)
and I go to put my headcover on. Well heres where I have the problem.

When I went to tighten the 12 bolts on the head cover, I realized 7 of the 12 bolt holes were stripped out. There are two long bolts that go down to the cylinder as well. What are you guys suggestions to fix this. I know I can helicoil it and everything, but I`m not very familiar with them and dont know too much about them. Also I REALLY don`t want to buy a new cylinder and head. I just got the 440 kit and HD studs in it, and valves and everything done. Please help me out.

KH426
11-01-2007, 08:08 PM
use a good helicoil kit lock tight and swedge them in good and you will not have any problems.

skatrdude20
11-01-2007, 08:20 PM
Hey what exactly would I use to swedge them in there? Also how would I get the helicoil into the 2 long bolt holes, the ones that go into the cylinder?

REPOMAN
11-01-2007, 09:56 PM
i had this same problem awhile back and i just took the bike to a local quad mechanic and he welded aluminum in the holes and then tapped them so it was like brand new. heli coils are a pain and this cost me under 100 bux to have done

dariusld
11-02-2007, 09:58 AM
Its like the engine isnt ment to be taken apart:mad:

400exrider707
11-02-2007, 11:45 AM
Originally posted by dariusld
Its like the engine isnt ment to be taken apart:mad:

No its like the bolts are supposed to be put back to torque specs, they are very very easily over-tightened, I've done it myself too, I'm not knocking anyone, but thats the truth of it.:ermm:

dariusld
11-02-2007, 01:12 PM
Originally posted by 400exrider707
No its like the bolts are supposed to be put back to torque specs, they are very very easily over-tightened, I've done it myself too, I'm not knocking anyone, but thats the truth of it.:ermm:

I've never used a torque wrench on these bolts, but I have only SNUGGED them down in sequence and have had trouble with all of them. Thats what makes me mad, I could understand if I was cranking on them. And I only use a 1/4 in. drive .The only thing I can think of is that I have taken the cover off about 6 times. And everytime I make sure the threads are clean on the bolts.

skatrdude20
11-02-2007, 05:17 PM
Well see I bought this head and cylinder off another kid, then did everything, and finally got my engine together and went to put it on, thats when I realized they are COMPLETELY stripped

400exrider707
11-02-2007, 05:55 PM
Originally posted by dariusld
I've never used a torque wrench on these bolts, but


famous last words?:p

zrpilot
11-02-2007, 06:12 PM
Originally posted by dariusld
I've never used a torque wrench on these bolts, but
--------------------------------------------------------------------------------
Originally posted by 400exrider707
famous last words?:p

I use a torque wrench and torque them to 48 In-lbs and have had NO problems!!!