Head Removal

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Jul 26, 2008
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Mighty Norton Knowledgeable,

Trying to dismantle the head on my 850. I am stuck on bolt #2. The bolt on the inside near the carbs. I cant get a wrench around it with the limited space. I also cant use sockets because of the small space.

Any suggestions on getting that bolt loosened up?
You will probably have to grind down a wrench to get it to fit on that nut!

I'm sure most of us Commando owners have our own "special tool" ground-down for that very purpose.

If you don't want to ruin an expensive (1/4" Whitworth) wrench, then I suggest you grind up a cheap 1/2 A/F or 13mm open ended wrench?
The jaws of the 1/2 A/F or 13mm wrench would also need to be ground out a little, in order to fit the 1/4" Whitworth (0.525"/13.34mm) nut hexagon.
Man that always was a misery. If I recall I also heated and bent a wrench to get a better angle. It is easier to start with a Whitworth.
Same here. Used an offset Whitworth on my 750 heads. Just got enough bite to crack it then a whole bunch of super mini turns.
I have always been able to remove the head with a ground down spanner of some sort. My main concern has always been replacing the head and getting the correct tension on the head bolts. How do you supposed to retorque accurately.
I've always guessed it by feel but never been confident until a few hundred miles is put on the engine.
What are the techniques for torqueing up the head bolts?
My technique is to use the wrench on a properly torqued fastener to get a "feel" for the amount of force needed on the wrench. Then go to the nut that's only accessible with the wrench. Keep in mind over torquing is worse than under torquing.

As someone else here mentioned, Helicoil those studs. The studs do not have to be Whitworth. A 3/8" stud of the proper length threaded 3/8-16 on one end, 3/8-24 on the other. I use a grade 8 bolt cut down to length. Use a grade 8 nut 3/8-24 and you are in business. All that stuff is available at your local hardware store. No need for specialty Helicoil and studs.
I take it then that people have had those studs pull out? When I worked on Nortons it was always the first rebuild and the bikes were not very old.
I never had a problem with those studs but that was many years ago. I have a lot to catch up on.
I've always gone by something I heard a long time ago and that is that a normal length spanner wrench pulled good and hard is 55 lbs. of torque. So, less hard, less torque, etc.
special tool for that nut

Hi Joe,

Ebay is a great thing. I found the special tool several years ago and bought it for $10. It's a double ended short well socket with a curved handle. The sockets are short enough to fit in there. Not sure about the tool number, but mine is stamped E.C. 21. Also fits the front long nuts going upward from the front of the cylinder (750 Commando).

Turns out there is a King Dick Whitworth wrench that fits perfectly to get that nut out.

The designated size for the nut in question is 1/4" BSW. It needs to be a thin wall box end wrench.

I ordered one from the great Phil at fairsparesamerica.com

Sometimes, cheap is okay.

The cheap Whitworth combo wrench set I have uses thin-walled box ends with 12 points, so you can just get that sucker in there and it works a treat.
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