Now YOU made me snort!
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On the road again at 40.............the bike that is
Haha, sumtimes ya get lucky, eh?
Some bonehead (me) over-tightened the tach cable to the adapter, probably to stop a leak without first looking at a parts diagram to see where it might be leaking from. When I removed the tach cable the adapter spun right out with it, and it was locked on there real good. Been spraying with PB Blaster for a week, nuthin, without wrecking the threads.
Was by a specialty hardware shop today and picked up a couple M16x1.5 jam nuts. Didn't have a lot of thread to work with. As it turned out the recess in these nuts was a large enough diameter to fit over the tach drive cable knurled connector.
Badaboom badabing, spun right out.
Some bonehead (me) over-tightened the tach cable to the adapter, probably to stop a leak without first looking at a parts diagram to see where it might be leaking from. When I removed the tach cable the adapter spun right out with it, and it was locked on there real good. Been spraying with PB Blaster for a week, nuthin, without wrecking the threads.
Was by a specialty hardware shop today and picked up a couple M16x1.5 jam nuts. Didn't have a lot of thread to work with. As it turned out the recess in these nuts was a large enough diameter to fit over the tach drive cable knurled connector.
Badaboom badabing, spun right out.
Gotta love it when a potentially nasty problem is solved in a quick, inexpensive and non-destructive fashion.
Pete
Pete
That was a great little solution Robin! Nice save.
Haha, thanks guys, ya nice little $2 fix. Probly the cheapest fix on this project!
Interesting. M16-1.5 nuts? Some of us were under the thinking that the threads were 5/8"-16, which is remarkedly close to M16-1.5...
Hmmm, well I never even considered trying an imperial size 2M so when I checked the thread pitch I got 1.5, and a quick measure said M16.
Here’s what it looks like. (metric and imperial)
EDIT: Add 18TPI pitch gauge photo
Here’s what it looks like. (metric and imperial)
EDIT: Add 18TPI pitch gauge photo
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Have exact same problem, I swear it wasn't me that did it!
Want me to send these to you gggGary? 
taped to a sheet of paper probably make it as a first class intnl letter.
The one I got was still on the cable, the cable nut disintegrated.
The one I got was still on the cable, the cable nut disintegrated.
It's between 16 and 18 tpi. 1inch is 25.4mm. Divided by 1.5 is 16.93 tpi.
....dang it - now where the heck did I put my 16.93 TPI guage??
That thing is always missing from my set.
That thing is always missing from my set.
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Thought I’d do a quick update and post up a couple of pics while putting things back together, some in particular for 2M. Didn’t want to hijack Chris k’s thread.
Jim your rebuild thread is amazing. I'm following along on the shop computer. What an awesome resource. Thanks buddy!
Boy they sure look purdy. (Note: ring gaps were properly oriented when installed).
Notice the U.S. Department of Homeland Security sticker on the piston boxes…..lol.
I know I'm repeating myself but you may remember the story from Jan 6, 2018……. from this post:
http://www.xs650.com/threads/on-the-road-again-at-40-the-bike-that-is.49360/page-33#post-535099
Cruizinimage wouldn’t ship these pistons to Canada. Danielblack added them to his order, Maxpete picked them up from Daniel while on a post Christmas family holiday to Phoenix, brought them to Canada in his carry on bag, and his daughter brought them to me in London.
I wondered if Pete might have any problems ‘smuggling’; those pistons into Canada. Well, IIRC as Pete recounted the story to me, the Security check officer questioned Pete as to the content of those boxes as he was boarding the plane.
Officer, “What’s in these boxes sir?”
Pete, “Those are pistons for a 1977 Yamaha XS650 motorcycle”.
Officer, “Ya, that’s what I was going to say. I guess you can’t hurt anyone with a piston, have a nice flight”.
Pete can correct me if I’m foggy in my recollections.
Ah, A Tale of Two Pistons.
Here are the pics I wanted to post for 2M.
Not quite sure how you guys would measure these, or how a machinist would, but my machinist did deck/skim the head so 3.7645 is probably more accurate. Hope these help 2M.
Jim your rebuild thread is amazing. I'm following along on the shop computer. What an awesome resource. Thanks buddy!
Boy they sure look purdy. (Note: ring gaps were properly oriented when installed).
Notice the U.S. Department of Homeland Security sticker on the piston boxes…..lol.
I know I'm repeating myself but you may remember the story from Jan 6, 2018……. from this post:
http://www.xs650.com/threads/on-the-road-again-at-40-the-bike-that-is.49360/page-33#post-535099
Cruizinimage wouldn’t ship these pistons to Canada. Danielblack added them to his order, Maxpete picked them up from Daniel while on a post Christmas family holiday to Phoenix, brought them to Canada in his carry on bag, and his daughter brought them to me in London.
I wondered if Pete might have any problems ‘smuggling’; those pistons into Canada. Well, IIRC as Pete recounted the story to me, the Security check officer questioned Pete as to the content of those boxes as he was boarding the plane.
Officer, “What’s in these boxes sir?”
Pete, “Those are pistons for a 1977 Yamaha XS650 motorcycle”.
Officer, “Ya, that’s what I was going to say. I guess you can’t hurt anyone with a piston, have a nice flight”.
Pete can correct me if I’m foggy in my recollections.
Ah, A Tale of Two Pistons.
Here are the pics I wanted to post for 2M.
Not quite sure how you guys would measure these, or how a machinist would, but my machinist did deck/skim the head so 3.7645 is probably more accurate. Hope these help 2M.
Thanx, Rob. Confirms this dimension.
An odd dimension, 3.765" = 95.63mm.
Edit: be sure to orient the valve pockets...
An odd dimension, 3.765" = 95.63mm.
Edit: be sure to orient the valve pockets...
Ok, good, no problem.
Yup, will do thanks. They are marked in case one forgot intake valves are larger than exhaust I guess.
Yup, will do thanks. They are marked in case one forgot intake valves are larger than exhaust I guess.
I noticed that the pistons are engraved 75.50. This was the same for my 2nd oversize pistons and when I had the rebore done the engineer said they did measure out to this. They must be using pretty accurate machines to manufacture these pistons. After installing the pistons I was forced to remove the head after 23 miles due to non-rotating valve. I noted that the bores had some scoring. I just wonder if the rings had some rough spots?? I had removed the rough edges/corners from setting the ring gaps and just wonder if the entire rings should have been sanded very lightly on their upper and lower perimeter edges??
IIRC Paul, back in January, my machinist said that as these are cast pistons one was a couple of thou different, something like that, hence he marked the left for me.
Where were you a couple of hours ago Paul? LOL
Where were you a couple of hours ago Paul? LOL
