A forum for owners of Yamaha TTR250 trail and enduro bikes!

zacht · Member

Oil Pressure Bleed Screw

TTRfan · Super Guru

Bad luck!

It would be worth considering buying a left hand drill bit so that as it bites into the remains of the bolt it would most likely unscrew it. The benefit of this is that it also wouldn't leave and swarf to fall into the oil line.

Can you get a drill in there to do it though? If not, maybe try a fine centre punch or similar to try and tap the remaining bolt anti clockwise to unscrew it - it might move!

Or you could just leave it and check the oil is pumping through by loosening the nearby banjo bolt in the oil pipe to the head.

Brian

zacht · Member

TTRfan wrote:
Bad luck!
It would be worth considering buying a left hand drill bit so that as it bites into the remains of the bolt it would most likely unscrew it. The benefit of this is that it also wouldn't leave and swarf to fall into the oil line.
Can you get a drill in there to do it though? If not, maybe try a fine centre punch or similar to try and tap the remaining bolt anti clockwise to unscrew it - it might move!
Or you could just leave it and check the oil is pumping through by loosening the nearby banjo bolt in the oil pipe to the head.
Brian

I think I'll have to remove the header pipe to access it regardless of which option I try. but yes, once that's removed I think I can get a drill in there. I'll give it a shot and see. The yamaha guys didn't recommend leaving the bolt "as is" because they thought the vibrations could slowly cause it to drop down further, eventually breaking free and disappearing into the oil line.

TTRfan · Super Guru

In which case you need something like this

zacht · Member

TTRfan wrote:
In which case you need something like this

Absolutely. Heading to the hardware store in about two hours to see what I can find.

zacht · Member

Well this job went sideways pretty fast. The bolt didn't break off cleanly, the part that remained in the threads was very jagged, and it was sunken down enough that I couldn't get a file to it to make it smooth for tapping for extraction. Reversing it out didn't work so it might just be screwed (no pun intended) now. Next step I can think of is just replacing the clutch case cover, which does include the oil filter unit and bleed screw. That seems to be a pretty straight forward work around here that would get me back up and running. Unless anyone has any other ideas or suggestions...?

pug · Guru

My next step on a sheared off bolt is always weld a nut on top it with the tig or mig welder this has near a 100% success rate as the heat cracks the thread lose as you are doing it

zacht · Member

pug wrote:
My next step on a sheared off bolt is always weld a nut on top it with the tig or mig welder this has near a 100% success rate as the heat cracks the thread lose as you are doing it

I'm lacking the skills and tools for that. Maybe I'll call a couple machine shops in the area and see if they can handle that for me. But I doubt I could get that done for cheaper than just replacing the clutch cover.

mossproof · Super Guru

The bleed screw goes into the top of the oil filter housing. I think if you remove the filter you will see the other end of the broken bolt. No danger of losing it in the depths of the engine. If you are really lucky, some of the bolt may protrude into the void so you can get a pair of grips on it and turn it. (But few of us are ever that lucky!!)

Worst case: take the clutch cover off to make it easier to work on, and drill the bolt out. You could try a small drill then hammer a torx bit into it and try turning that (inwards or out doesn't matter if the head has sheared off), or Brian's lefty drillbit might grab it.

Worst worst case: drill and tap a bigger thread. Any bolt with a copper washer will seal it.

Good luck!

iran ttr250 · Member

mossproof wrote:
The bleed screw goes into the top of the oil filter housing. I think if you remove the filter you will see the other end of the broken bolt. No danger of losing it in the depths of the engine. If you are really lucky, some of the bolt may protrude into the void so you can get a pair of grips on it and turn it. (But few of us are ever that lucky!!)

Worst case: take the clutch cover off to make it easier to work on, and drill the bolt out. You could try a small drill then hammer a torx bit into it and try turning that (inwards or out doesn't matter if the head has sheared off), or Brian's lefty drillbit might grab it.

Worst worst case: drill and tap a bigger thread. Any bolt with a copper washer will seal it.

Good luck!

iam agree this work. the best work

zacht · Member

mossproof wrote:
The bleed screw goes into the top of the oil filter housing. I think if you remove the filter you will see the other end of the broken bolt. No danger of losing it in the depths of the engine. If you are really lucky, some of the bolt may protrude into the void so you can get a pair of grips on it and turn it. (But few of us are ever that lucky!!)

Worst case: take the clutch cover off to make it easier to work on, and drill the bolt out. You could try a small drill then hammer a torx bit into it and try turning that (inwards or out doesn't matter if the head has sheared off), or Brian's lefty drillbit might grab it.

Worst worst case: drill and tap a bigger thread. Any bolt with a copper washer will seal it.

Good luck!

Thanks for the tips. I did check the filter housing and unfortunately there is none of the broken bolt coming through to try and grab. I tried using a bolt extractor but that didn't work worth a damn. I'm to the point of getting a new clutch cover for $170, so yeah might as well try just drilling it out and see how it goes. Thanks for the tip.