Cylinder Problem

[pullasach]

I have been having a problem with the studs for the head in my cylinder. The holes have been enlarged and helicoils have been placed in them to allow a good torque. However, I am having problems with 1 of them and it tightens to 23 ft-lb but after heating up the engine it will not and is just a pain because of repetitive head gasket blows.
Ok, so here is the thing, I have tried filling the hole with jb-weld once and repeating the helicoil steps and allowing the jbweld to fill in the spots where the aluminum was reamed out. I was hoping this would work, but It just blew again.

What should I do? My quad wants to run!

[gh500]

insert the hole and re tap it depending on how bad it is you just to need to be sure to and have good thread engagement on the insert since their is not a lot of meat around the stud bosses it's the last shot thats why i say insert it re tap it not another threadsert type of repair

[pullasach]

I was reading previous forums. Does anyone think trinity can fix it up for me? I'm on my last leg for this cylinder..and thats not good because this cylinder is worth alot of money!

[CR480R]

That really sucks... I have 3 heli-coiled studs on my lt... they have held up perfectly so far... I wonder if lt500 studs could be used to repair your cylinder? 8mm top..10mm bottom... just a thought...

[gh500]

i dont know if i would go that route since the boss is small and if helicoil is not holding the root of the thread of a helicoil is ~9.5mm for 8mm.125pitch helicoil that doesnt leave much for the 10mm stud to grab .5mm .020"

[CR480R]

weld it up... re-surface deck and re-tap...

[gh500]

if you weld it you will distort the cyl and it will need to be re-bored that is an option if inserting wont fix it and welding a deep small hole up in ALU is a real trick and I'm not a big fan of welding if their is another option

[CR480R]

I was only suggesting welding as a last resort... The stud boss would probably have to be cut out some in order to be welded properly, but a a bore-job and a slight cut on the deck is better than scrapping a cylinder...

[ONLY2STROKES]

bigger helicoil.

[pullasach]

I'll contact my buddy at the honda shop here in town, and I'll see what he can do. I had the idea of welding and reboring but the fact that I have a new wiseco piston and just had this cylinder rehoned and is already bored 1.5mm overbore, is a reason I have looked down on that, but it is an option I guess. I really don't think there is room for expanding the holes any larger than 10mm towards to bottom anyways without it tearing into the ports, unless anyone has done it and knows from experience.