I'm still doing the strip-down of the C11G frame but have hit another issue. The front saddle fixing bolt, listed in the spares list as 33-4089 and shown as part 24 on plate 7, is stuck and ain't goin' nowhere. The head of the bolt was already rounded off, so I cut it off, but the rest of the bolt doesn't want to move in either direction. The front support bracket for the dual seat does pivot freely but I can't remove it yet without potentially bending out the legs and I don't want to do that except as a last resort.
It's the same situation with the backstay frame bolt, part no 29-4103, listed as part 27 on plate 7. The bolt won't move and the battery carrier plate (I think) is trapped there. Thankfully the head of this bolt hasn't been destroyed yet, but I can't separate the frame and the rear subframe until I can get this bolt off.
I've tried using a hammer and drift to push out the saddle bolt but it hasn't moved. I've tried using a long spanner and attached a second spanner to the frame bolt but it hasn't moved either. I've tried applying heat with my blowtorch but I have to admit that I'm still finding my way with the thing and it's entirely possible that I'm applying heat to the wrong place. I've even tried using strong language, but while that made me feel better and less stressed, it didn't do anything for the bolts!
Can anyone suggest anything? Should I try to drill them out with a HSS bit?
If, as a last resort you attempt to drill the shaft out you might consider using a left handed drill bit, occasionally with the anti clockwise rotation of the drill bit it may encourage the remains of the bolt to begin unscrewing.
You could maybe try using a stud extractor as this will attempt to turn the bolt. I assume it has been well soaked in penetrating oil. Use plasticine to create a dam around the top of the cut off bolt so that you get a pool of penetrating oil and leave it for a couple of days.
Hi,
After the penetrating oil for few days try the heat again but it will need quite a bit as the heat will get drawn away by the rest of the frame. I think that it is a through bolt rather than threaded in the lug and some have a locating tube in there as well so I would try a lot of heat applied quickly and try to whack it with a good heavy hammer and drift whilst it is hot. Another thing to try if you have an electric welder is to strike an arc on the bolt for a few seconds. This has the effect of breaking the corrosion that is holding the bolt allowing it to be knocked out.
Dave.
Hi,
Before resorting to drilling try thermal shock, heat and quench loads of times. Plenty of release oil soaking as suggested. Turn clockwise and anti clockwise when it starts to move keep washing it with release oil.
Best wishes..
Excellent suggestions all, many thanks. I won't give up and will report back as soon as they're out.
After that, there are only two jobs left - remove the plungers and the left-hand bolt at the bottom of the front down-tube, all equally stuck. Oh the joys of motorcycling!
Hi how is your c11g's going , I have just purchased 2 for restoration, both 1955,s , I have stripped both
For soda blasting and powder coating , just trying to strip front forks but need a special seal holder tool .
If you do attempt to drill the bolts out it may pay you to use left handed drill bits...
Thermal shocking / Hot & Cold treatment is a good method to try.
I have had the same situation before my self with a stuck rounded off bolt, had to tig weld the largest cap head i could fit onto the top of the bolt.
Then thermal shocked it out.
Good luck hope you get it out ok.
garyp
When the bolt begins to move, apply penetrating oil then tap it back in again. This is better than trying to drift it only in one direction. As you drift it back and forth, apply penetrating oil to any newly revealed bit of bolt or hole. I did this successfully a couple of months ago, also getting it nice and hot with a blowtorch then drifting it right away, before everything cooled off.
Quote from: peely on 11 Nov, 2021, 15:50
Hi how is your c11g's going , I have just purchased 2 for restoration, both 1955,s , I have stripped both
For soda blasting and powder coating , just trying to strip front forks but need a special seal holder tool .
Thanks everyone for the further tips. I parked the project in the late spring as I made progress on my Bultaco. Then the opportunity came up to buy a complete and running 1954 C11G. The '55 frame is still in the shed and I may return to it at some stage.