Topic: Am I installing cylinder barrels correctly?

[cakey]

So double checked all my manuals and the parts fiche on CSMNL.

1. Put the pistons and circlips on rods. Arrow on piston top facing exhaust side.
2. Put 2 orings in the middle top
3. Put 2 dowels in bottom each side
4. Gasket on. A bit of interference with the side of the cam chain tensioner so I trimmed a bit off.
5. Light oil on the sides of the pistons
6. Barrels over the top
7. Put the two outside pistons in the up position and inserted the barrel over the top.
8. Then lifted the two middle pistons in the up position and got the over.
9. Almost got the barrels all the way down but did not want to go right down on the exhaust side.
10. Lifted the barrels back up and trims some gasket from around the cam guide pin which I thought might be stopping it going all the way down.
11. Put the barrels back down and the middle ring broke on number 2 piston
12. Totally jacked off and need to buy another set.

My questions are

1. Am I putting the barrels on correctly? Got it the first time and stuffed it the next
2. I bought the .50 oversize pistons from David Silvers so do I need to buy another ring set from them or can I buy any .050 oversize set?
3. On the parts schematic for the barrels it says that part number (3) rubber insert is a vital rubber seal between the cylinder barrel and cylinder head. I cannot work out which one it is or see where it goes. Can anyone offer advice

Yep kicking myself again!

[Don R]

If the gasket needed trimmed, it wanted to be flipped over. The hole is slightly offset. Probably won't hurt anything.

[cakey]

 Yep I'm a self confessed idiot Don. Thanks mate, I just went out and flipped it over and it fits perfect.

Problem one out the way.

[cakey]

3. On the parts schematic for the barrels it says that part number (3) rubber insert is a vital rubber seal between the cylinder barrel and cylinder head. I cannot work out which one it is or see where it goes. Can anyone offer advice

Yep kicking myself again!

Think I figured the rubber seal out. I think it's the rubber inserts that go between the fins. It's just that the description makes it sound like a seal between the barrel and head.

2 problems down

[martin99]

Sounds good to me Cakey. Shame about the broken ring but don't be too hard on yourself I expect most on here have done it. Guess you're squeezing 'em in with your fingers? Usually ok but if you have the proper clamps it makes life easier.

Just one thing I would add which you've probably done anyway but haven't mentioned it. Space your ring gaps approx 120 degrees apart. Some argue they move in use, some don't, but I always like to be reassured that there is a good seal there when I rebuild a motor.

[cakey]

Thanks Oldschoolnuts.

Yeah my second engine rebuild and my second broken ring, I'm gutted.

Yes I have spaced the ring 120 degrees apart.

Cheapest set I have found here in OZ so far is $100 so it's been an expensive mistake.

What are the ring clamps you mention. My standard ones a way to tall to fit under the barrels?

[martin99]

I know this link won't be a lot of good to you, but this is the sort of thing I'm thinking of...

http://www.ebay.co.uk/itm/Piston-Ring-Clamps-Pair-for-Bore-Size-65-70mm-/181262597301?pt=UK_Motorcycle_Parts_13&hash=item2a3417bcb5

[Medyo Bastos]

i'd still run with fingertips, instead of clamps...

[cakey]

Thanks for the link. I see what you are talking about now.

It does not look like I can get them around here so it looks like its back to the fingertips.

[70CB750]

I used hose clamps to install rings.  You gotta polish edges to make sure rings slip off easily, but  that's all there is to it.

[cakey]

I went to the Honda shop and ordered a set of original Honda rings and a Honda barrel gasket as well to replace the one I trim up. Didn't order a Head gasket ($185) thought I would just continue with the Vesrah one I have.

When I was at the shop the spare parts guy asked me if I wanted the orings for the barrels? Can anyone confirm if there are orings that go over each barrel? If so then I missed them when I stripped the engine down.

Everything happens for a reason.maybe I broke the ring so stop putting the barrels on without the orings on the barrels.

Thanks in advance.

[mick7504]

Put some blocks under the 2 pistons that you're working with to keep 'em squared up as well mate.
Patience and no force is a priority.

[cakey]

Good advice Mick. I will give it a go. I think it was force that did me in.

Answered my own question. Had a look at the barrels and found the orings and replaced with new ones out the kit. The old ones broke apart pretty easy so maybe it was all worth it in the long run.

Learning as I go

[mick7504]

Good onya mate.
Take your time and you'll get it right.
That 750 will be breathin' fire before you know it.