Date: Mon, 20 Jul 1998
From: Frank Palmeri
I decided to run a compression test this weekend. After a thorough warm up ride I screwed in the compression tester, the kind that retains the highest reading. Left side read 150 after two kicks, and toped out at 170 after 6 or 7 kicks. Right side read 140 after 2 kicks, and topped out at 165. I'm not sure if this means my compression is 140/150 or 165/170, but it does indicate the right side is a little weaker that the left. Probably need new seats it the future.
Frank
Date: Mon, 20 Jul 1998 19:05:08 -0700
From: Eric William Lamberts
These are good numbers, and mean that valves are seating well, and the rings are not worn. The numbers should be within 10% of each other, and it's the final number that counts. Anything over 150 is very good.
Eric Lamberts
16.2 Running with, and fixing a striped Stud.
Date: Sat, 5 Sep 1998 22:53:16 -0400 (EDT)
From: Steven R. Schoner
Reply to message from Joe Schofield of Thu, 03 Sep
>>1. In most people's experience with this head, is this more
likely to be
>>the stud stripping or the nut?
>
>Mike. It's the threads in the head. Period.
>
>>2. If it is the stud stripping, how long can one ride it in
this
>>condition?
>
>Forever.
>
>>3. ... could I put an oversize nut or a few fat washers under
it to move the >>nut down to an unstripped area of the stud threads?
>
>See (1) above. There will be no 'unstripped area' !
>
>>... I'd like to put 1000 or so (gentle) miles on it first.
>
>I don't think you'll have a problem.
>
>Regards, Joe Schofield.
You'll have the problem of your engine puking oil all over your boots, the road, everywhere. And a lower compression besides, oils burning, all that and more.
Fix--
1) Remove the head.
2) Remove the stripped studs, (threads will be stripped in the head under the exhaust ports)
3) Drill holes so that you can tap for 1/2" x 13 TPI.
4) Tap holes in aluminium head with 1/2" x 13 TPI
(should be .625" deep, but no more than .680")
5) Get 1/2" x 13 TPI allthread. Steel will work, but if you can get silicon bronze that is better.
6) Cut two lengths of it .615" long.
7) Drill and tap for the same thread as your stud.
(I drilled and tapped for a 3/8" x 24 TPI capscrew and completely eliminated the longnuts and studs. It is harder to get together, but works even better than the original.)
8) screw the inserts into the head after coating the threads with high temp loctite.
(Use a bolt in the internal threads of the insert to do this) Make sure that the insert seats below the level of the head face.
9) Assemble the head to the engine, and if you can torque the stud nuts to 30' lbs.
(I made a special attachment to do this. But another way is to get a torque wrench 3/8" drive, get an attachment that fits to this that make is a 1/2" drive, and you will find that a box end wrench will fit to the stud nut, and the 1/2" drive into the open end. Before you use it as a torque wrench tough, you must measure the entire length, then divide this total length of both wrenches into the original length of the torque wrench. You will get a decimal >1, that is some factor that is something like .75 or thereabouts. Multiply this number by 30' lbs. and you will now have the setting for your extended torque wrench so as to deliver the proper 30' lbs. to the nut.
If all this seems too confusing, you can do what most do-- guess how much pressure to apply to the standard wrench after taking note of how much force the other nuts that were torqued had.
10) Enjoy a Norton engine that will never have stripped studs again. It is a permanent fix that last "forever"
I did this to mine, and have never regretted the trouble.
--
Steven R. Schoner (Meteorite Man and Seeker)
___________________________________________________________________________
Compared to the Infinite we know next to nothing. What good we
do with
the little we do know is the key to wisdom.
Date: Mon, 20 Jul 1998 08:48:31 -0400
From: KEN DUBEY
Somebody Wrote:
>I know that leaving my bike on the sidestand overnight guarantees
a
>smoking left pipe the next morning. I don't know why, but it's not
a problem
>if I always use the centre stand.
>Now I find that even leaving the bike to idle on the side stand also
starts
>the pipe smoking. Even if the bike has been run several miles and
is fully
>warmed up -
>place it on the centre stand = no smoke,
>place it on the side stand = smoke from left pipe.
>If I blip the throttle it even leaks out around the left header pipe.
>If I then drive the bike it clears up after a few blocks.
>
> ??
Valve guides!! When the bike is leaned over, all the oil in the head is flowing down past the top of the guides on the left side. If it's leaking around the header pipe, I'd say the exhaust guide on the left is history, which means the rest of them probably need replacement too.
Ken