Cylinders are off . . .

[mack]

Studs

I put black shrink wrap on mine. Got them from napa. Clean the studs first.

[TopCatGr58]

Hey Ian,

Good find, same seller but with the 0.5mm overbore, leaves plenty of room for later bores. If your engine was running, then I seriously doubt that you would need more than a 0.5mm overbore to get it back to clean/round cylinders.

Yes, the machine shop will want the pistons to match bore the cylinders to the pistons, and they will mark them 1-4 to match the cylinders, but it would be nice to let them know they are usually numbered 1-4 from left to right, just to help reduce confusion.

That's a great price of $97.00 to bore all 4 cylinders! The machine shop I used was a bike racing shop, and they also put a nice TAPER below the bottom of the piston travel range of the cylinders to make it easier to put the jugs/cylinders onto the pistons without as much compression of the rings, was actually able to do it by hand without a ring compressor. I would ask them to do the same, I can't remember if they are that way OEM? But a nice trick is to use a set of screw pipe clamps to compress the rings that you can then take off once you get the pistons into the cylinders, helps reduce the chance of breaking rings.

T.C.

[IanDMacDonald]

Morning !

I presume I'll receive the cylinders back from the machine shop this week. My question(s) pertain to the type of oil to use prior to start-up, and actual break-in procedure.

Do I need to use a break-in oil? Recommendations?

What is the break-in procedure for new rings?

Keep in-mind, I'm doing all of this prior to storing it for the Winter, so once I complete the rebuild, I'll run it and put it in storage.

[DiverRay]

If you are going to run it then store it, I would just store it! Unless you plan on about 600 miles, don't bother beyond assembly lube on all bearings, and non detergent oil mixed with a little synthetic oil for everything else. The tiny bit of synthetic should keep an oil film on everything for the winter, as well as the fogging oil I hope you use.
Once you ARE going to run it at least 500 miles, break in the rings by having the bike ready to ride BEFORE starting for more than about 2 minutes. Once fired, find a strait road and in second gear go from about 2K to 7K RPMs as quickly as possible, then chop the throttle and let the engine slow the bike down to about 2K and do it 2 more times. AFTER that, ride the bike easy, under about 3.5K RPMs , but vary the speed a little. after 100 miles, 5K is your limit, 200 miles, 6K, etc. The main thing is after the five minute ring break in, take it easy but VARY THE SPEED as you cruise. 45mph for 2 minutes to 60mph for 2 minutes, and back to 55mph, etc.

[dansmith65]

I haven't tried this and I'm not sure where I found the link anymore, but I saved this in case I ever need to break in new rings: http://mototuneusa.com/break_in_secrets.htm

[MaximPhil]

I haven't tried this and I'm not sure where I found the link anymore, but I saved this in case I ever need to break in new rings: http://mototuneusa.com/break_in_secrets.htm

Hi Dan,
Different animal.That article is new cars (engines) coming from the factory in recent years. driving off the lot.
Ian is dealing with a 40 year old REBUILT motor.
If it were my hard work and harder earned cash I would follow DiveRay's suggestions.

Phil

[dansmith65]

Hi Dan,
Different animal.That article is new cars (engines) coming from the factory in recent years. driving off the lot.
Ian is dealing with a 40 year old REBUILT motor.
If it were my hard work and harder earned cash I would follow DiveRay's suggestions.

Phil

Thanks for mentioning that; it's been a while since I read that article. I was just re-reading it and noticed it mentioning newer manufacturing processes. I think I'll add a warning to the clipped article for the next time I read it!

[IanDMacDonald]

For those curious: $52/cylinder for bore/hone, plus $6/piston for setting the end gap on the rings. Worth it in my opinion to have a good-running engine.

Front-end is all done. I'll put the new tires on in the Spring. Cylinders and head goes on this weekend. I made those piston holders out of scrap UHMW I had laying around at work.

[IanDMacDonald]

Started with getting the rings on the pistons today. The oil rings went on easy, then the compression rings gave me trouble. Too stiff to pry apart, and not worth breaking. The right tool for the job was necessary: piston ring expander. Called every auto parts store . . . "Ehh . . . Did you say compressor?" . . . "No, I did not. I said expander tool" . . . "Looks like an online too"

Called a buddy who's brother was a Master mechanic. He recommended an old hole in the wall automotive store in Flint. It did not even have computers!!! Tools in every aisle from the 70's, 80's, and 90's, that's never been sold!!! They had the piston ring expanders by "Lisle". $6.99!!! I was in there for 2 hours looking around!!! My dad would have loved it! So many neat tools.

So, rings went on easy with the tool. Pistons on the conrods easy enough. Service manual jigs in on the middle two cylinders, squeeze the rings one layer at a time, dead blow to bring the cylinders down, middle two done, outside cylinders done, hammer it down one corner at a time, and the cylinder block is done.

Tomorrow morning, I'm going to lift it back up a notch, and run a small bead of black rtv silicone along the outside perimeter of the base gasket. I don't want to chance any leaks.

[MPittma100]

Ultra Grey

The Ultra Grey Silicone is a much better product for your cylinder seal. Grey will yield much better results than the black.

[motoman]

The Ultra Grey Silicone is a much better product for your cylinder seal. Grey will yield much better results than the black.

Totally agree!

[Schming]

Good thread but PICS would make it great

[IanDMacDonald]

The Ultra Grey Silicone is a much better product for your cylinder seal. Grey will yield much better results than the black.

Thanks Mike!

And, Schming- I always say I will, but never do. I wanted to do it for the steering head bearings, but I suppose these projects separate the long-term XS owners, from the Craigslist sellers. I'm a noob compared to some like Todd, Greg, Moto, Mike(s), TC, Phil, etc.

What I can tell you is that every year, I learn more & more about these bikes!

[IanDMacDonald]

Got the engine buttoned-up this evening. I'll admit, it wasn't without a moment of panic . . .

So, got the cylinder head on, cams in, caps on, chains taut, first set of sprocket bolts on, following the manual to the "T". Turn crank to "C" mark, ACCT in, turn crank a few revolutions . . . EEEEEEEEE!!! As the manual says . . . If you feel it binding, STOP!!! Deja vu' set in, as this was where I was in the beginning when I bent all of my intake valves. Except, this time I did not force the crank, nor anything else stupid. I stopped, and thought very hard. What did I do wrong? What happened? I backed-up, reversed a step, I immediately removed the sprocket bolts, pulled the sprockets off the cam shoulders, rotated the crank to the "T" mark, and started over. What did I do different? Instead of rotating the crank to get to the "C" mark, I stuck a wood dowel in the CCT port to keep pressure on the cam chain guides, rotated the crank to get the sprockets to a point where I could get the other bolts in, THEN inserted the ACCT. At this point, everything turned smooth, with no binding.

However, the drama was not over. Figured I'd check the valve lash, and be done with it for awhile. A few of the intake valves were tight, but what REALLY made me nervous wad the clearance on exhaust valve #3 was .30 mm. Never seen my clearances that out of spec. I'm thinking bent valve . . . compression check across all four cylinders was 120 psi (you'd think new rings would have gave me a higher compression number?) So, at-least I have compression. My plugs are old, Advance Auto closes at 8p, it's 7:50p. $20 for 4 plugs??? They used to be like $2???

Anywho . . . Gotta put the exhaust system back on, carbs, and debate on firing it up to check things over, or just put it away in storage, and fire it up in the Spring? The compression numbers on across the cylinders bother me a little. Thoughts? Bore job was for 72mm
Said the pistons were almost perfect. He was surprised
Ring gaps were set by him. I don't think I bent any rings installing them. I guess I would have known, right?

[MPittma100]

Hind sight is 20-20

If you take a cylinder head to a machine shop, also take the cams so they can set the valve lash. Saves you that task.

Given the info that you posted, it is time to start it, tune it, and ride it.