Topic: Clymer says I'm gonna break my rings

[gregimotis]

CB750F1



Is there any danger of breaking or otherwise damaging the rings when sliding them back into the cylinders during reassembly?  Any suggestions for the task?

I thought if an extra set of hands working underneath while lowering the cylinder block wasn't going easily, then I'd try a compressing them with a hose clamp and sliding it down and off as we go.

I didn't find a thread, so maybe it isn't that difficult...

[Bodi]

I suppose Clymer might be right about something - by accident.
Anyway, the bottoms of the sleeves have a bevelled edge that makes slipping the rings in without any compressor relatively easy... kust takes a bit of dexterity and coordination. Block one piston (and thus two) up and get the rings for that pair in, then release the block and slip the other pair's rings in as the first pair goes down and the second pair come up. By being impatient or ham-handed you can probably break a ring but getting them in undamaged has never been particularly challenging for me. When dealing with an overbored engine the bevel gets shorter and tighter so it is harder, aftermarket sleeves may be different as well.

[MRieck]

I suppose Clymer might be right about something - by accident.
Anyway, the bottoms of the sleeves have a bevelled edge that makes slipping the rings in without any compressor relatively easy... kust takes a bit of dexterity and coordination. Block one piston (and thus two) up and get the rings for that pair in, then release the block and slip the other pair's rings in as the first pair goes down and the second pair come up. By being impatient or ham-handed you can probably break a ring but getting them in undamaged has never been particularly challenging for me. When dealing with an overbored engine the bevel gets shorter and tighter so it is harder, aftermarket sleeves may be different as well.

I think it was you that said in another thread that anything can be broken, installed wrong or generally screwed up. I wholeheartedly agree.

[City Boy]

I have re and re'd dozens of 750's,many with large over bores.Getting the rings started 2 pistons at a time was always nail biting time.However,on my last build,a dohc 900 F,tried something new.Installed piston/rod assembly individually into cylinder,then mounted cylinder/piston/rod assembly onto upper crankcase,then flip over and mount crank to rods.Much easier!

[KB02]

I broke a ring on my F1 when I put the engine back together. Time and patience (and maybe a spare set of rings) win the day. 

[schneider419]

my two cents?? worth. i just did this on my 350f. after much nail biting, searching the web, and asking other bike owners, i decided what the heck it's only a classic bike, lets go for it. i made a nylon stick out of a piece of nylon sheet about 3/8 of an inch thick, 1 inch or so wide, and about 3 inches long. i beveled one end, this is your ring pusher. then i turned the motor over until both inside pistons are at tdc. i staggered the ring end gaps 120 degrees or so apart. then i took the cylinder, oiled all the bores, and lowered it down and took my other hand and got the middle two pistons to start into the bore. they will stop when they hit the first rings. now take what ever you use for a ring pusher and start to work the top ring on one piston in. the weight of the cylinder will hold the ring in. the ring will pop in and the cylinder will drop a little on one side. don't force it any farther. go to the other piston and do the same thing. at first you will have to keep checking the piston because it will want to cock sideways till you get the first ring in. keep doing this until all 3 rings are in. now you can rest for a minute. now turn the crank and guide the outside two into place and do it all over again. once you get the hang of it, it goes pretty easy. it took me about 1/2 hour to do it. by the way don't forget the base gasket, i ALMOST DID!! hope this helps.     

[05c50]

Funny that you should mention the base gasket. When I assembled my 750, I got all the rings started,then realized that I forgot the gasket. After that, I kept telling myself that it was good practice and experience! Instead of the nylon stick,I used aluminum beer cans to make kinda funnel to compress rings. I cut off the top and bottom,slit the cans up the side,smoothed the edges,and wrapped them around the pistons. The cans are thin enough to fit into the cylinders and still leave room for the rings. I actually only needed 2 cans,but decided to empty 4. 

.....Paul

[City Boy]

Thats a great tip c50.I will try that next time.Rock On.

[gregimotis]

Turning the engine without the camchain/camshaft in place?  How does one get that lined up properly again when done?
 I had hoped not to move the engine at all.

[Gordon]

Turning the engine without the camchain/camshaft in place?  How does one get that lined up properly again when done?
 I had hoped not to move the engine at all.

You're going to have to turn the crankshaft to get both piston pairs into their cylinders, there's not much of a way around it.  Your manual should explain the procedure for lining everything up when installing the cam chain.  It's pretty straightforward.

[rbmgf7]

I have re and re'd dozens of 750's,many with large over bores.Getting the rings started 2 pistons at a time was always nail biting time.However,on my last build,a dohc 900 F,tried something new.Installed piston/rod assembly individually into cylinder,then mounted cylinder/piston/rod assembly onto upper crankcase,then flip over and mount crank to rods.Much easier!

from what i've seen, that's how they're assembled from the factory.

I haven't had the chance to assemble my 750 engine yet, however on my kz i was able to slide the pistons in the cylinder (but just enough clearence to slip the writs pins in) and then drop the cylinders on the block and slide the pins in.

[hymodyne]

I have used a large aviator (hose) clamps, the kind with a worm gear to compress the rings on two pistons at a time, then switch them to the other two. the clamps give me the ability to adjust the tightness of compression of the rings against the piston as I bump them down into the juggs.

hym

[754]

Good Lord, has e veryone forgotten Popsicle (tm) sticks

Ringpusher of choice for decades..................


Whip up a set of piston blocks, take a 1/2 hr or less.. makes it sooo much easier.. if you done it before..should be a 15 min job to pop barrel on or less.

cut 4 pcs of 1x1 or 1x2 wood & use 4 elastics if need be..

[Gordon]

I really can't remember ever having that much of a problem getting the jugs back on just using my fingernails to compress the rings.  I do the inner two cylinders first, then rotate the crankshaft and do the outer two. 

I did make the mistake, the first time, of forgetting the base gasket!