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Cylinder head bolts not tightening!!

6K views 15 replies 5 participants last post by  MirGz 
#1 ·
Please someone help me...took head off, upon reinstalling 3 bolts just spin and dont tighten....from internet research i came to tge conclusion that the holes in the block must have stripped threading....now I have a couple questions about my options.

1. Can i run a m10 "thread chaser" to "Clean threads" and try again? Anyone have experience chasing a stripped hole this way with success?

2. Could I add another washer to bolt and see if it torques down that way? (This was just a random thought I had but wasnt sure sinse the camshaft spins right over the head bolts)

3. Called machine shop and they want $75 a helicoil smh is this possible to do myself? Seen many people say yes but just asking. Ive been wrenching on cars for about 7 years and just started with bikes.

4. If I do helicoil will it be a "permanent fix" as in if I had to take head off again, would i run into problems once again ehen its time to reinstall?

5. And last, I see most ppl say either "Timesert" or "Helicoil" which is or permanent ......which would you recommend?


Pleasd anyone with experience Please Please help.... Im going crazy..

Ps. For anyone wondering how i got into this stuation...I let a friend learn to ride bike on 7/2/16....you guessed it, he crashes and brakth the brake bracket and little other pieces so while I waited for parts i figured let me clean carbs since the bike was barely startable and my license was going suspended from 7/17/16 -8/18/16 anyways so why not...upon carb reinstall, throttle bracket nut slips out my hand and couldnt find it for 3 weeks....tissue was out intake when this happened and valves were "open"...magnet wasnt able to go through the spark hole to fish out so i pulled the heads just to be safe rather than sorry...there was no ****ing nut in the cylinder! so i was happy and mad that i had to tear the bike down for no reason...now upon head reinstall, 3 bolts just spin...tighten then loosen and just spin...FML I just want to ride man....
 
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#2 ·
It sounds really odd that the threads would just be stripped without applying torque to a bolt first. Did you overtighten the bolt and cause this?

Regardless, helicoils are easy and are a permanent fix but you need the correct tap and installation tool to do them yourself. Their not crazy expensive but if you **** it up it wont be pretty.

A tip I have is to find a local machine shop in the area and give them a call. Forget the bike mechanic. If you can bring your head to a shop, I doubt they'd charge more than $100. Helicoils themselves are cheap and I am sure a shop has the tool and the tap they'd need. Although, metric threads are a different story. Worth a shot to call around and see if you can talk to someone. Plead your situation and they might throw you a bone. I have gotten plates machined with numerous helicoils for $150 total. A shop saying they want 225 for 3 friggen holes is out of their mind.
 
#3 ·
I'm not exactly following here. The head is held onto the crankcase by nuts on studs. Are the nuts stripped on the studs? Or are the studs stripped and turning in the crank case? If so how in the heck did you put enough torque on them to do THAT? If the thread on the studs where the nut goes are stripped, you can replace the studs. If you managed to pull the studs out of their threads, then you probably need to put down the tools and take it to someone qualified, before you do more damage.
 
#5 ·
I'm not exactly following here. The head is held onto the crankcase by nuts on studs. Are the nuts stripped on the studs? Or are the studs stripped and turning in the crank case? If so how in the heck did you put enough torque on them to do THAT? If the thread on the studs where the nut goes are stripped, you can replace the studs. If you managed to pull the studs out of their threads, then you probably need to put down the tools and take it to someone qualified, before you do more damage.
You must be a very strong guy to apply that much pressure tightening those. Wth >_< best of luck and let us know what you find.

Ummm na bro your wrong my dude idk if you worked on a 2001 before but the head is "not" held on by nuts on studs like you say.....theres bolts that fall thru the head and tighten onto block....the holes in the block are stripped and if you cant take a head off i dont think you should be working on anything imo because its really not that hard of a job if you understand the modern combustion engine......WHAT happened WAS the Autozone torque wrench I was using has a collar that "locks" the torque setting in place right above the handle...i locked it but mustve accidently unlocked it with my hand while i was tighting FML....Bolt called for 51NM or 37.5 ft/lbs in 2 stages ... This was the 2nd tightening stage and i turned the wrench and notice it was a lil snug but didnt hear the audible click yet so tightened a lil more hoping to hear it still didnt so moved on to next two bolts in the tightening sequence and same thing..... so when I looked at the torque, the wrench was now "unlocked" smh so it wasnt even Locked on a torque and trust I didnt have to exort that much force to strip soft aluminum... 37.5 ft/lbs is hardly high torque...barely went past snug.....I think im going to do a TimeSert......ANYBODY HAVE PERSONAL EXPERIENCE WITH THESE?
 
#6 ·
You never mentioned what year your bike was, so fine, it wouldn't take the amount of torque to strip as the stud arrangement that is used on all R6 engines from 2006 onward. I have not pulled a head from a first gen R6, so my mistake. I have Had heads off 3rd gen R6 engines and many FZR engines before that (which also had studs) so I wouldn't have thought Yamaha would have changed the arrangement on the 99-02. My apologies.

I have personal experience with both timesert and heli-coils. Both are permanent, but the timesert is a better option. A little more involved in the installation process, but since it is a solid sleeve, there is little to no issue with it when removing the bolt in the future.
 
#7 ·
Oooooo ok i see where your comming from now bro mybad shouldve said it was a 2001 mybad :) yea i like the ifea of the solid timesert instead of the spiraled helicoil too just cant find them in stores and the universal head kit with the guide is like $400 comepared to like $90 without the guide it seems like....and the places around me only use helicoils smh .....I just dont wanna have to replace a helicoil down the line if it ****s up and be mad i didnt do timesert the first time....you think if i let the shop helicoil it ill be alright? If i needed to tear down engine 1 more time? Not that i plan to but you never know...if not i think ill just sit her up and wait for the timeserts
 
#8 ·
Go to McMaster-Carr mcmastercarr.com and search for threaded inserts. You can narrow the search by material and thread size. There are other inserts that are as good (keensert, key locking, etc) You want a stainless material. The other 2 things to consider are 1. The length you need, and 2. Are the stripped holes ones that the dowels go in. If they have a dowel that goes around the bolt, the flange on the timesert may not be narrow enough. It might also make it difficult to use a key lock type because you have to drive the keys down, and you might not be able to do that in a recessed hole. There are some that you basically drill and tap the hole and screw the insert in. They will have thread lock on the outside that you let set and it prevents the insert from loosening. As I said, there are several opyions, and the particular case may determine which is the best.

McMaster-Carr
 
#14 ·
*Update* Helicoils worked perfectly for anyone that encounters the same problem (even though id rather the timeserts)....put bike back together and is running fine. Thanks everyone and thanks 8ball for giving me the courage to use the helicoils since you had experience. Ride safe yall, lata.
 
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