Heli coil in head keeps pulling out

[paintslinga2010]

The motor I bought came with a heli coil in one of the holes on the exhaust port. I'm using bolts instead of studs and the bolt with the heli coil pulled the helicoil out. I went and bought another insert and put it in. It lasted about 3 rides and pulled out looking like a spring. What's my next option? Should I put some loc tite or JB weld on the next insert before i put it in? I do not want to pull the head or the motor.

 

[elwood]

I'd locktite the helicoil to the head with the strongest locktite you can find

 

[Pete7072]

You can try loctite. I used a heli coil in a mustang head bolt and its held up for the last 4 years. Haven't hear of them popping out. Maybe the coil or bolt isn't the right size.

 

[duneracerweston]

Drill and tap it to a 8mX1.25 and oversize the hole in your headpipe

 

[1998yamahawarrior]

Your supposed to use red Locktite on Heli-coils

 

[bikewarrior350]

either do what duner said or try these. its like a helicoil but its a solid peice of metal so it cant pull out nearly as easily. ive used them before and they work really well if theres enough space to fit them since they are m10 on the outside. plus then you are putting a bolt into steel threads not aluminum

http://www.mcmaster.com/#threaded-inserts/=eu44a0

 

[bikewarrior350]

sorry link doesnt work but heres the part number 90245A171. just put it in the search box. they are called key-clocking inserts

 

[1998yamahawarrior]

Trust me guys, they are supposed to be locktited in. Besides being common sense, I just went over this a couple weeks back.

 

[beastlywarrior228]

you might have rotten aluminum, the cylinders eventually reach a point where they dont hold studs anymore

 

[MotoArts]

There's a reason why they come OE with studs instead of bolts... I'd ditch the bolt idea for sure.

 

['00 WO-YA!]

Anytime you use a heli-coil it needs to have Loc-tite. Kits usually come with a drill bit, tap & coils. I fear that the hole is too large for the coils you're trying to use. You may have to do as already suggested, enlarge the hole in the headpipe & use a larger heli-coil & STUD, no bolts. Loc-tite, Loc-tite, Loc-tite, RED, we clear? Cool!

 

[paintslinga2010]

anyone have the size on the head studs? I looked when I went to o'reilly. I'll try the lowe's down the street next.

 

[MidwayUSA]

anyone have the size on the head studs? I looked when I went to o'reilly. I'll try the lowe's down the street next.

6mm x 1.0

Red loctite will not hold near the heat of the exhaust. We use heat to loosen it to get bolts and studs out. There is a purple high heat stuff that we got one time that will work. If the hole is drilled to the right size and tapping fluid is used on the tap, you can bottom the stud out and not need loctite.

 

[paintslinga2010]

I'm going nutty trying to find studs. Have any of you had to buy these lately? Where did you find them?

 

[duneracerweston]

I just got 8mx1.25x50 bolts cut the heads off cleaned the threads and locktited them in works great

 

[elwood]

Here you go http://www.motorsportmonster.com/fiche_section_detail.asp

they are #6 in the parts finche

 

[paintslinga2010]

So I am going to have to drill out the hole and put in a larger heli-coil. Any more things i should try before I do this? Also has anyone done this repair with the engine still in the frame?

 

[duneracerweston]

Cant do both with it in the frame I would drill ant tap and change the bolt size and restud it and forget heli coil

 

[paintslinga2010]

I'll look into it. I am afraid the stud will be too large and a nut will not fit between the header pipe and the stud.

 

[duneracerweston]

It will work I have oversized studs in mine