Topic: Do I need to pull the cylinders? (pics)

[altf4]

Allright, I pulled the head as you can see (to replace the head gasket), and as I begin to shed some light on the rest of the motor I can see that the base gasket is in fact leaking also. (I guess this is common???).

This would definitely be the first time I've removed cylinders, so how do I go about this? Do I rotate the crank until the cylinders come out of the bore and then remove the wrist pins? or does the jugg pull up and away from the cylinders and crankcase without removing the pistons?

Also, do I need a ring compressor set to disassemble the pistons? (I know I'll need one to assemble).

Thanks,

donny

[BlindJoe]

Do you have a service manual for the bike? If not you should get one, I think it would answer most of your questions.

[CBJoe]

What bike??? 350???

You can probably download the manual here...

http://forums.sohc4.net/index.php?topic=17788.0

read, read, read....  and have fun 

Cheers...Joe

[altf4]

Yea it's a 350F, and I have the manual - it is nonspecific about the actual procedure to disassemble the cylinder - it actually just shows the jugg there in one pic and gone in the next, with the piston still connected to the rod, which i guess means the jugg just lifts away from the pistons???

I am sure I sound like an idiot, bear with me....   

[CBJoe]

I'm not familiar with the 350 (or anything other than a 650 for that matter ), but with the head off, you should be able to "lift" the cylinder straight up and off the pistons.  You might need to "lightly" tap around the base of the block with a rubber mallet to separate it from the base gasket.  DON'T hit too hard or you'll break a fin.  There are probably two guide dowels on the left and right side that place it into position.  It might take some shimmying but it should come off.

Joe

[mattcb350f]

You beat me to it Joe 

Here's what I was gonna say.... same thing really

I would use a rubber mallet to jar it loose, than gently begin pulling it up. There are two dowels at the base of the cylinder so it might be a little tight. Resist the urge to jam a screwdriver in there to pry it loose. This damages the mating surface between the case and the cylinder and the cooling fins break easy on these so you have to be gently all around. Once you get it loose, the jug just slides away from the pistons.

you won't need a ring compessor to disassemble the pistons, but make sure that you don't loose any piston clips down into the bottom end. As a bit of insurance, place some clean rags around the conecting rods to cover the hole.

 Matt.

[Cvillechopper]

They've got you covered on getting the jugs off.  Go ahead and order new rings now cause you'll want to replace them while you're at this point.  You should be able to get a top-end gasket kit that'll give you everything from the base gasket up.  When you go to change the rings out you'll want to pick up a set of ring pliers (spreaders really) so you don't bugger the rings putting them on.  To get the pistons and rings back into the cylinder takes some patience.  the manual should have a decent description but here's how I do it.

Get 2 & 3 cylinders at the top of their stroke.  Slide the cylinders down onto the pistons until the rings stop against the sleeve.  Make sure you have the rings spaced at 120 degrees and use your fingernails to gently push the rings inward and upward.  As you get one ring in, move to the other piston and do the same ring on that one.  Once you have 2 & 3 in, slowly push the cylinders downward until you get 1 & 4 seated.  It gets tricky but it's basically that same just working on keeping 2 & 3 from coming out while you work that additional ring in.  There's a bevel at the base of each sleeve so that helps quite a bit.

Good luck.  Just go slow and you'll be fine.

[carl]

My cb500 has specific routed notches around the base of the cylinder that are pry points. Regarding ring compressors - for my reassembly last year, I used large hose clamps from the hardware store.

[754]

Bang the cylinder with heel of your hand first..

cuz any mallet if you slip can damage a fin..

dont use a pry point if you dont have to...

[altf4]

You guys are awesome - thanks alot.

[altf4]

One step closer.

[lordmoonpie]

No need for ring compressors any which way - just patience, lots of oil on the bores and some good strong fingernails (red ones optional ).

The bores have plenty of lead in so it's easy to squeeze the rings gently in even after a modest overbore. The key is always patience. I've taken up to an hour on my 750 to do this and ironically, up to 4 on the CB450 twin...

Oh - a small scissor jack is useful for bigger barrels which you can use for additional support assuming you're doign this on your own. You can fit it between a set of bores and wind it down gently so there's no sudden barrel drops onto nice piston crown type accidents.

[754]

use blocks under the cylinder when re installing, should be way quicker.. under an hour..