Engine Job- remove cylinder: How?

[duckling]

Having a cylinder block welded, and am asking, How does one break the chain? and;
How does one reinstall the pistons with rings properly?
I want to consider removing the cylinder and head in one piece to preserve the head gasket.
Thanks for your thoughts, all
Cameron

[ragedigital]

How does one reinstall the pistons with rings properly?

Piston Ring Compressor

[ragedigital]

How does one break the chain?

Chain breaker, though you might be able to use a small disc on a grinder.

Then reorder a chain link joint: http://fiche.ronayers.com/Index.cfm/Mod ... FT_-_CHAIN

[duckling]

How does one reinstall the pistons with rings properly?

Piston Ring Compressor

Can the cylinder be removed with pistons still installed by pulling their pins? I think the crank is two down and two up. Does that configuration allow this?

[ragedigital]

I don't think that's your biggest concern. I'm sure they'll come right out. You're going to have a heck of a time getting them reinstalled in such tight quarters though.

[reelrazor]

a) you are talking CAM chain, correct?

Doesn't need to be cut. SHOULDN'T be cut

b) saving the head gasket/removing the head along with the cylinder block is a pipe dream-DON'T try it.


and

c: you HAVE TO remove the cams to get to head/cylinder bolts anyway...the compression pressure on the head gasket will be removed, the cams will be out...WHY??? would you think of saving the $30 head gasket...just to have to do ALL THE WORK again when the used one fails??

[trump19]

yo if you need a Manuel i have one i can send via email let me know

[duckling]

a) you are talking CAM chain, correct?

Doesn't need to be cut. SHOULDN'T be cut

b) saving the head gasket/removing the head along with the cylinder block is a pipe dream-DON'T try it.

c: you HAVE TO remove the cams to get to head/cylinder bolts anyway...the compression pressure on the head gasket will be removed, the cams will be out...WHY??? would you think of saving the $30 head gasket..?

I planned on removing the cams, but then you're right, the compression would create a suction. The manual tells me I need to break a link to get the thing off. The head gasket retails for $85 and I'd be paying $66 from the discount place. Where can I get one for $30? That would be great!

[bweight]

As for re-installing the pistons into the cylinders you don't necessarily need a piston ring compressor.. I just rebuilt my 600 motor and it was a little bit of a struggle, but it can be done with 4 hands and a little patience....

When you're putting the motor back together. Rotate it so that pistons # 2 & 3 are at TDC... put those 2 pistons on the rods and secure them with he spring clips. Now, the tricky part. 1 person hold the pistons upright and the other slowly lower the cylinders down over top. There is quite a bit of flexibility in the rings so you can actually use your fingers to squeeze the rings into the jug as the cylinders come down. Make sure they are completely inside the channels on the piston or you will damage the rings and or the cylinders... Once those are into the cylinders, slowly lower the jugs down a little more. Now put pistons # 1 & 4 on the rods and secure them with the spring clips... Repeat the process as before. Make sure all the rings on the pistons are in the cylinders and slowly lower the cylinders down and proceed with the rest of the steps for assembling the motor..

IF you encounter ANY resistance while lowering the jugs down, stop and pull them off again and make sure everything is still seated properly and repeat it all over.. Also, before you start, make sure you apply some 4 stroke oil to the cylinders, rings and pistons..

When we did this the other night, I actually bent one of the bottom oil rings on cyl #4.. luckily I had another one here I could use and we got it right the next time.. With all 4 pistons installed properly the jugs should drop down. I had to LIGHTLY tap each side a couple of times with a rubber mallet to get it moving, but everything is fine and buttoned back up now..


As for the head gasket.... I just bought one here in Canada for $22 at the local Yamaha Dealership.. $85 seems overpriced unless it's a Cometic which seems to be their going rate...


Hope this helps..

[reelrazor]

YOu can do this as a hybrid type of install.

Do as bweight says on 2 and 3..TDC...hand squeeze the rings into place, slide cylinder down


BUT, you can pull the wrist pins on 1 and 4 and have 1 and 4 pistons started in the cylinder block before you do this. Leave the inner (#1 toward 2, and #4 toward 3) circlips in place. And leave the wrist pin bore just below the cylinder. Then slide the pins thru the piston and rod combo. Make sure a good install of the remaining circlips is done, then seat the assembly.

With a little experience and patience, this can be done by one person

[thatkid]

I thought about this and it looked tricky. I came up with this.

With 2 & 3 at TDC, slide up the block until access to 1 & 4 wrist pins is gained, cover the crankshaft with a cloth filling any holes (in-case you drop a circlip or anything else) remove the outer circlips and wrist pins. Slide 1 & 4 pistons fully into their cylinders. Slide the block up to access 2 & 3 wrist pins, remove them. Remove the block with pistons in situ. Replacement would be a simple reversal. Would that work?

If i ever need to do mine, i'd give it a shot could/would save a lot of time and hassle.

[duckling]

Surprisingly, I learned that a head can be removed with cams and lifter intact, without bringing them out of alignment. I never would have guessed that the cams have access holes in them. The chain must be broken, however, and a new, $4 link obtained from Yamaha and replaced with. The re-installation of my pistons looks to be a daunting tasks, best performed with two sets of hands. I wan to know, what should I think when rod big-end bearings show a little rocking looseness? Machine shop guy says "no up and down" motion should be observed, but... I can shift each rod side-to side, not sliding, but rocking...