YAMAHA Ultramatic - Infinitely rotating bolt

[adr94]

Hey,

I have an old Bruin from 2006 and I am trying to revive it.

I am now trying to remove the last bolt on the ultramatic cover but it is turning infinitely. I don't want to force and risk breaking the cover.

Do you know what I could do ? Do you have any tips or even was in this situation once ?

 

Thanks,  

[Gwbarm]

Sounds like bolt is stripped if you take some vice grip pliers  put on the bolt pull out at the same time you are turning it may catch and come on out

[adr94]

I tried but maybe not hard enough. It is rusty but the head of the bolt is ok. It is turning, I can feel it from the other side of the transmission cover. 

[Gwbarm]

If you have enough room to get a screwdriver head under the bolt you can pry out at the same time you are turning the bolt and see iff that will do it, sometimes if it has a raised area on the case where the threads reside it can break loose from the case then the only way to get it off is to cut the head off the bolt, i hope that hasnt happened, i have only seen it happen a couple of times, usually from metal fatigue.  

[Mech]

Since it's the last bolt, try levering the cover out a little somewhere else further away from the bolt, then slip some thin metal plate in and slide it along as near as you can get to that bolt, then push the cover back in so as to lever the cover over the metal plate. That will try and pull the bolt out, then slowly turn and lever and the bolt might get a grip and come out, or, it will just grind it's way out. if it comes a bit put a thicker bit of metal in and do it again. Use a wide bit of metal, not a screwdriver, so it doesn't damage the cases.

[Gwbarm]

Good idea! Sounds like that may work 

[Mech]

"trained professional", as we say when wielding the big hammer.

[adr94]

19 hours ago, Mech said:

Since it's the last bolt, try levering the cover out a little somewhere else further away from the bolt, then slip some thin metal plate in and slide it along as near as you can get to that bolt, then push the cover back in so as to lever the cover over the metal plate. That will try and pull the bolt out, then slowly turn and lever and the bolt might get a grip and come out, or, it will just grind it's way out. if it comes a bit put a thicker bit of metal in and do it again. Use a wide bit of metal, not a screwdriver, so it doesn't damage the cases.

Very good idea ! It gave me some leverage, the bolt was harder to turn but I was not able to get a grip and get it out. It is really annoying. I'll try again tomorrow, I hope it will work.

Thank you all for the ideas.

[Mech]

Use something thin to start with, a 24 thou feeler might do, , and get it right close to the bolt if you can. That gets the most leverage and will generally be the most effective. Then use two feelers or panel steel or such, then two bits of panel.. Getting the metal close to the bolt is the trick to getting a lot of leverage and a lot of drawing power. It might seem better to use a thicker bit of metal, which will give more travel of the bolt, but to start off you need the leverage of a thin bit close in.

It will probably take the threads right out of the case so then you drill it and use an insert like these..  They self tap and you put them in using a bolt and nut, with something under the nut that's smaller diameter than the insert so you can wind it down just barely below the surface of the case. They come in different threads on the inside and the outside. Using course outer threads is slightly stronger, but the fine outer threads are smaller diameter and will probably be better for that job.

[adr94]

Hey,

I was able to remove the bolt !

I used metal levers on the cover and added inox wires around the tiny space between the bolt and the cover. It created enough space to use a little screwdriver as lever on the bolt and it finally came out.

I was even able to save the thread as it was possible to screw a bolt from the other side of the cover hole.

Thank you for your help,

[Gwbarm]

Good glad nothing was broken

[Mech]

Good one. That bolt looks just about ready to break !

 

[Gwbarm]

It must have been loose for years or either cross threaded. Are the threads in the case damaged. Almost looks like the wrong thread pitch bolt was used. 

[Mech]

The thread pitch looks right to me, and those heads aren't common on common old bolts. I think the pitch is right.. That wasting though.. It wouldn't surprise me if that bolt had been wound in and/or out with a power wrench.. Winding bolts too fast causes galling and damaged threads.

 

[Gwbarm]

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