Cylinder Stud Bolts

[quadman21]

Got a question guys. I've had my 440 back for about two weeks. I raced one Harescramble and then the next day my Head gasket blew. It was a metal cometic gasket. I din't panic but I got another. When I went to install it I noticed that the nuts for the head were loose. I mean one was hand loose and not torqued. So I figure there's my problem. But when reinstalled the new gasket I could not get those same bolts to torque out. I put as much toque as I could and obviously the gasket blew again because I couldn't get the 33ft lbs that I needed. This time i have inspected and found that two of my cylinder studs were stripped. I am going to have them helicoiled and order a paper (or whatever you call that material) headgasket and hope that it holds the 33ft lbs I need. Do you guys have any other advice before I get this done? Oh, and buy the way, I had a local shop do the engine so this lowsy macahnic had to know when he put it together that something wasn't right when he put it together!

[PsychoDave]

i retorqued my head gasket about a week after my 416 kit was put in...the bolts were at like 15 ft lbs...so i set them at 33....it is fine now.

dID SOMEWHAT THE SAME THING, BUT MINE JUST SNAPPED. I instead of a stud just put a stainless bolt on there. No problems since, and thats been over a year!!!!.

[400exJOE]

i did the same thing. I am almost sure that they are not supposed to be torqued down that much. The clymer manuals have an error in them ad thats what i have. Kinda pissed me off!

[RAPTORAZ]

From what I hear it is a somewhat common occurence on 440EX's. Curtis Sparks fix for it is drilling the head stud holes deeper and putting in longer studs. My buddy is going through the same problem as you right now. He is sending his jug to Sparks next week. Sparks only charges $25.00 and says this will cure the problem. My buddy has lost two gaskets as well.

[Blackguywithouta400]

I spoke to Tom Miller at TMM before i did my motor and he sujested that i go with the 425 now since he will be building a stroker motor this winter for me, he originaly told me about the problem your having with your 440 back then, his cure for people who have to have the 440 was a better designed stud made of stronger material. He uses a Case Hardend steal stud thats less prone to pulling he says. The main problem lies in the removal of the sleave, the studs have to be removed and there just not put back as honda had them, but as always there is a way around the problem.

[quadman21]

Thanks guys. I don't feel as bad now. I was real wooried that I might have to buy a whole new cylinder. Sometimes I think I should have stuck with my 416. This 440 has been a real headache for me. I'm taking my cylindar to Legacy ATV out of High Point, NC tomorrow and have them helicoil it for me. If something happens down the road at least it is repairable. Raptoraz, TC will drill, Tap, and replace with longer studs for only 25 bucks? That actaully sounds worth waiting for but I am anxious to get this beast going. I have only had a chance to race and then ride it once.

Head bolts busting eh? YIKES!

True enough though about the Cometic gasket, my buddy's on his second one now and we modified it.

If you look at the gasket, the front left corner (with respect to the motor) has far more surface area than anywhere else on the gasket. When I took the old gasket off, I checked it with a micrometer, and there was no squish on it. The gasket comes from cometic at 0.045" thickness and everywhere on the old gasket EXCEPT for the front left corner was 0.041", the front left was still 0.045". There seems to be a problem there with compressing the gasket, and I'm convinced that it is because there is too much gasket to compress. So what I did was trimmed the gasket on that corner around all the head bolts and the C-BORED hole in the cylinder head in the hopes that it would gain more PSI on the remaining part of the gasket. So far so good!

As for torquing the head bolts, Terry Marcum told my buddy to torque them at 33 ft/lbs, then fire up the machine, let it warm up (no buzzing the throttle), then shut it off, and re-torque to 35 ft/lbs.