Saving Old Seagulls

Been stripping my recently accquired 102 for a bit of a cosmetic overhaul,
in the process ive managed to snap 3 out of 4 bolts that retain the tank brackets to the head/barrel!
to compound problems i have also snapped a stud extracter in one of the broken bolt ends.
Any one know how thick the casting is around the tank mount lugs? there is enough room to redrill/tap some new mounting points i'm just worried about drilling into the water gallery(ie:in z rather then x/y)I know lots of you will say i should have just undone the tank straps but i never/i wish i had/help anyone got any good ideas?

Hmmm.

I would say that measuring the depth of the one you have successfully extracted would then allow you to drill and tap. Different batches were different thicknesses.

BUT if you do accidentally go through into the water jacket it's not the end of the world - good quality sealant in the threads would prevent coolant leaking out.

I have a 102 where the water jacket has been breached - most probably because the bolt was a bit too long. This apparently was fairly common, and British Seagull would simply pug it up with some sort of goopy stuff, and sent it on its way.

Heat is a good thing when removing these bolts; same with other studs.

Oh, and yes, the phrase you use as the title to your post is the most common pair of words uttered in my workshop.

This afternoon's 'Oh Bugger' was used when I managed to pry the Woodruff key from the crankshaft of my SNP; it flew off into the paraffin bowl which has a thick layer of filth at the bottom. The ensuing rummage for the offending key knocked the bowl over, soaking my shoe and foot.

The phrase was accompanied by others familiar in the litany of Seagull maintenance.

I did find the key, and what's more restrained myself from using the propane torch for the remainder of the session.

Tomorrow's use of the phrase will be when I fail to find (again) the clutch for that motor. I have a horrible feeling it may have been put onto a customer's 102 by accident. Oh Bugger.

Good luck...

Im afraid that the phrases i sometimes use in the workshop are a little heavier than bugger[at times]

I had the same problem recently with two of these which had sheared off flush with the top of the holes.With the block removed from the motor I managed to remove them by heating the block around the mounting holes and then cutting a slot in the ends of the sheared off bolts with a very small Dremel cut-off wheel (about 20mm diameter).
I found that after heating I was able to use a screwdriver in the slots to unscrew them.
Drilling out and re-tapping should be feasible provided the drill is centered accurately on the bolt ends.The broken off extractor could be a problem as it is probably as hard as the drill bit and may need annealing to soften it.
There are some useful ideas here: http://www.asashop.org/autoinc/may2003/techtotech.htm

Best of luck
Steve

Thanks for that chaps,i will re-drill tap new threads .
I couldn't beleave they snapped,i was using plenty of heat and they had had a overnight wd40 bath but there you go!Charles thanks for advice about the water jacket,would you beleave a stupid thing like that kept me awake last night!Maybe we should have a OH BUGGER section to this forum?

As a follow up to my broken bolts/stud extractor "oh bugger" moment,i have today re-drilled/tapped the tank bracket mounting lugs,found i could drill 15mm deep without breaking through the jacket,i had alreadymade some custom bolts to replace the rusted origanels(why did seagull use mild steel fasteners but use corrosion proof materials almost every else?)
m6 thread with 7/16 af hex heads(i'm lucky enough to work for a enginering company so strange 1 offs are no problem).
All was going well untill i had my next "oh bugger" i dropped my newly re-sprayed tank(actualy it was a "oh you stupid ****")!!!

Paul they are 1/4 BSF not M6 same pitch bigger diameter.

1/4 dia. 0.0385 pitch. 0.0246 depth. 55.0 degree. 26 T.P.I.

No charles, sorry you miss understood, i re-drilled and tapped new threads,m6 threads,

i also made new set screws with a m6 thread but with 7/16 af hex heads(11.11mm)rather than the standard 10mm hex to keep it all imperial,i would have used bsf but my company don't stock the correct screw cut inserts(were fully cnc i'm afraid!)we only ever produce metric or unc/unf threads(60 degree)so rather than face akward questions as to why i needed some rather obsolete inserts i used the nearest i had to hand.
I made them out of 316 stainless so they should last longer than the originals!

I'm supprised the old thread stayed in there, not much metal left.

I moved all them down a bit!thats why i asked about water jacket thickness etc, there was no chance of ever getting the carbide stud extracter out with out going down the spark eroding road(more awkard questions at work!).
Any way its all turned out ok the tank still fits ,its just sitting a little lower than normal(approx 15mm).tomorrows task is to fit the tank without either dropping it or scratching it