ripped out head bolt threads on bottom half on daily rider!

J

Joey

New Member
I ripped the head threads off somehow.. (vibrated loose..) and i tried to re thread it with a M8-1.25 bit... but now, i cant find a bolt for it..

any ideas of what to do anyone?
just as i was about to put a jackshaft kit on it :(
 
Last edited by a moderator:
Call an industrial screw company, or check Tractor supply co or Home Depot for metric all thread rod.

Or you may find autotomotive or motorcycle specific studs that can be used.

Industrial screw companies(or Graingers or Reid tool supply) sell thread inserts(called EZserts) that are screwed into a larger tapped hole, and you screw the original size screw in to it.

Helicoils are an option too if you take the motor to a shop. The instalation tools for helicoils are sorta expensive.
 
what brand motor? size? i have studs i could send you but do you need a helicoil? what is the orig thread?
 
thanks to everyone that replied.

Yes i do need helicoils.. but in australia its way too expensive!
$110 for a kit!
i just cant slap new bolts on there and off i go..
what i was thinking is inserting pins through the bolt and crankcase? to hold the bolt in place.. would that work?

as i really dont want to give up my bottom end.. it was running so good, and i just got the transfer ports matched..

any suggestions about my idea of inserting pins?

Also my motor is just a PK80 i suppose.
just a normal engine, all parts are interchangeable with the gt5
 
Pinning a stud in place seems a bit sketchy to me........ But what the hay, try it out. It may work just fine. Do you feel qualified enough to be a guinea pig?

As for suggestions on how to do it: Drill the hole in the case as far away from the cylinder deck surface as possible, and be sure that there is enough parent metal around it so as to fight off cracking the case due to fatigue.
 
Long bolt and washers to adjust fnial length, allowing all the threads in the hole to be used???and lock tite??
 
If you have good threads in the case, the pin may help with strength .
The pin method, alone, will not take the tension needed to torque the head down.
You can use thread inserts instead of helicoils. Only special tool needed is the tap for the inserts.

Google "Reid Tool Supply" look for "thread inserts" They are cheap,come in all sizes and the taps prolly about $15

http://www.reidsupply.com/GrpResults.aspx?pid=10021784&aitm=303-6&apid=10021784
 
Last edited:
do you have jb stick in oz? if so pack the hole tight and redrill and tap to a bolt you can find somewhere 100mm is the leghnth you need a pk uses a m8 1.25 where a gt5 uses 8 x 1.0
 
I had seen those a few years back,maybe even befor my beginning computer days,thanks for a refresher link
 
from past experiance I have ripped those inserts out. I like ss helicoils they dont come out and they arent just expensive in oz they cost the same here for a kit just 1 size too. a few years back i baught a master kit from hf and it was 60 bucks and i still have it never broke any of the tools it came with either.
 
Or you can take the whole motor apart get some one to weld the stripped hole shut. Then drill and retap it. This is why and the only place me personally I like to use red lock tight. I will only use it at the engine block side of the head studs tho and this is the only place that I use it just for the head studs.. As red lock tight is a permanent thread locker.
 
Everyone, i just drilled a pin in it and put loctite in it along with a 8.25mm threaded rod, goes perfect, engine has higher compression from the new head i made,
but the thing that is keeping me down is that i also installed a HD jackshaft but the thing is.. the sprocket on the right that goes to the crank keeps coming off.. and making the chain drop making a nice cut in my leg :) ive tryed making it tighter, no luck..
anyone care to help me?
 
if it is the little gear on the J-shaft,I remember the pic's/instructions ,to locate the operating position of the set screw for the gears on the shaft ,and file a flat on the shaft for the set screw,,,,,also how tight is the chain before the gear leaves,,,,
 
corgi1 said:
if it is the little gear on the J-shaft,I remember the pic's/instructions ,to locate the operating position of the set screw for the gears on the shaft ,and file a flat on the shaft for the set screw,,,,,also how tight is the chain before the gear leaves,,,,
Click to expand...

yes its the little gear, its all locked in perfectly and everything, yet its still coming out..
also what are the shims for in the package?

the tension on the chain is just perfect,not too tight not too loose..
but from the engine.. its extremely tight... cant get 5mm of flex from it..
 
I have the SBP HD shift kit.. not the cheap one :) its the newest one.
and yes, i have filed the space in..
 
My buddy put 3/8 studs in his cause he kept stripping them and they worked but thats the absolute biggest you can go and thats pushing it. dont go any bigger than you have too!
 
You must log in or register to reply here.
Back
Top