Author Topic: Icefire's 79 CB650 Project (Read 5855 times)

rb550four · « **Reply #25 on:** February 25, 2015, 08:47:49 AM »

Ouch on the pistons.
I have run across PO issues with wrong plugs before...the last time involved a perfectly good head , unfortunately I didn't check the spark plug threading before reassembly. Man was I pissed when 2 of the 4 plugs wouldn't bottom out. Don't forget to check yours , so this doesn't happen to you.
There are all kinds of ways to get an engine unstuck, which way are you going with first?

Icefire · « **Reply #26 on:** February 25, 2015, 08:54:20 AM »

So far I have cleaned all the debris off the Pistons and sprayed some WD around the Pistons last night . Going to do a second spray today then see if I get any movement tomorrow.
Any suggestion to loosen them up would be greatly appreciated.

rb550four · « **Reply #27 on:** February 25, 2015, 02:23:54 PM »

Some guys soak'em till they break loose. done that, can take a while
I've soaked the cylinders and hung the jug from the rafters a couple inches off the work bench on the front ,and the rear up on a 2x4 . Letting the engine weight do the work.Better
Have hung the jugs with the engine still in the cradle letting the entire bike 's weight do the work. better yet.
I have done both of the last two and used a 1" face smoothing hammer (napa part 6-5140) in an air hammer over a large socket , over a piece of leather or wood, hitting just a little bit on each piston, while hanging to break the seal on the unknown offending sealed piston. I like that best, no waiting around. Just have to not beat the piss out of it,a few short blasts and they are usually broke free. I sick a washclothe size rag on the piston top leaving excess around the cylinder walls so they don't get beat up I like this the best.
Some guys set the jugs on fire an swear that's the way to go.
Lots of ways to do it.

Icefire · « **Reply #28 on:** February 27, 2015, 06:39:37 PM »

After soaking the Pistons with WD for a few days I used a hammer handle and centred it in the middle of the Pistons and used another med size hammer and hit it a few times. I did this to all 4 Pistons and then tried to remove the cylinder. The cylinder began to move and # 2 and # 3 came free, # 1 was loose but # 4 only moved to the lower section of the cylinder. It is jammed in the cylinder and at this point will not move any further. I used a propane torch and heated the cylinder and piston at two separate intervals allowing it to cool down then gave it a couple more hits with the hammer handle but there was no movement. I sprayed more WD and will let it sit for a few more days.
I am now going to proceed to put time into the build, clean up the head, pull the valves, lap them and install new seals.

rb550four · « **Reply #29 on:** February 27, 2015, 10:35:54 PM »

I tie off the head on something higher so the crankcase weight will allow the jugs to stay up as the pistons and the crank are pulled through them when the pistons are free.

this is in the cradle but it works the same way when the engine is out ,back mounts on a 2x4 and the front mounts off the table a couple inches.

side view
a couple taps on the sticking #4 and it should look like

I hope yours look a bit better

Icefire · « **Reply #30 on:** February 28, 2015, 04:37:56 PM »

set up the cylinder today on the parts bike to get #4 piston loose. Strapped it over a 4x4 and cinched it up so the weight of the bike was pulling on it. I used a purswader to hit a second hammer to drive the piston down. After multiple hits it finally let go. Unfortunately the cycling er is so rust and pitted that it cannot be used for the project bike.

Icefire · « **Reply #31 on:** February 28, 2015, 04:52:20 PM »

I then began to take the cylinder off the project bike which came off easily with a few taps with a rubber hammer. Spent a few hrs cleaning the old gaskets off and wire wheeled the surface to have it ready for when I am ready to install it.
Once it was cleaned up I was wiping the cylinder walls and came across some cracks / lines in cylinder #3. This was very disappointing to come across especially after the cylinder on the other bike was not usable.
Can the jugs be replaced in these cylinders or would it be more visible to pick up another cylinder?

Retro Rocket · « **Reply #32 on:** February 28, 2015, 05:36:06 PM »

Just put some new sleeves in, not hard to do....

Icefire · « **Reply #33 on:** March 01, 2015, 08:47:16 AM »

I checked out some prices on a new Set of sleeves, averaging close to $175 - $200 ca. Purchasing a used cylinder looks like the way to go,

rb550four · « **Reply #34 on:** March 01, 2015, 11:58:02 AM »

I don't know anything about these, haven't the need for them yet.
http://www.ebay.com/itm/79-82-HONDA-CB650-1-00mm-OVERSIZE-PISTONS-SET-4-PISTONS-INCLUDE-CI-CB650APS-2-/161569761113?pt=Motorcycles_Parts_Accessories&hash=item259e4ee759&vxp=mtr

Has anyone used these here?
Any good?

Or found a better product?

Trad · « **Reply #35 on:** March 01, 2015, 03:42:56 PM »

Swap in a fresh cast iron sleeve. No big deal. Just a heads up that with the wire wheel you used to remove the gasket material, you likely made an uneven surface on that cylinder's gasket surface. You should have that milled flat.

rtbmrgl · « **Reply #36 on:** March 01, 2015, 09:42:28 PM »

Quote from: Icefire on February 28, 2015, 04:52:20 PM

I then began to take the cylinder off the project bike which came off easily with a few taps with a rubber hammer. Spent a few hrs cleaning the old gaskets off and wire wheeled the surface to have it ready for when I am ready to install it.
Once it was cleaned up I was wiping the cylinder walls and came across some cracks / lines in cylinder #3. This was very disappointing to come across especially after the cylinder on the other bike was not usable.
Can the jugs be replaced in these cylinders or would it be more visible to pick up another cylinder?

Hey Icefire, Its hard to tell by pics, are you they are cracks in the cylinder. With all the rust it may just be eaten a grove, if so you could bore it out and oversize pistons.
Just a thought

JimJamerino · « **Reply #37 on:** March 03, 2015, 10:22:28 AM »

The cylinder block is aluminum. The individual cylinders are cast iron sleeves- these sleeves are what you see protruding from the bottom of the block. The sleeves can be removed by heating the block in an oven, then tapping out a hammer. If you have 4 good sleeves between the two engines, you should be able to assemble them into one whole, useable cylinder block.

And I'm with Trad... using a wire wheel to remove the gasket material probably gouged the gasket surface. It seems inconsequential, but even the slightest grooves are enough to cause oil leaks and loss of compression. If you put new sleeves in, it wouldn't be a bad idea to have it milled anyways.

Icefire · « **Reply #38 on:** March 03, 2015, 10:40:28 AM »

I have been actually thinking if doing just that. Remove a good sleeve from the parts bike and replace the bad one. Read about putting the cylinder in the BBQ and heating it up to 350 for 15 pr do mins and the sleeves should just drop out.
As for the wire wheel it is a brass wire, very soft which I have used on numerous projects in the past with no issues . I use a flat blade to remove the old gasket and then the brass wire wheel to buff any debri off which leaves a smooth surface.
Will try the sleeve swap this weekend.

Icefire · « **Reply #39 on:** March 03, 2015, 04:53:00 PM »

I stopped in at princess auto today and noticed they had honing tools on sale so I decided to pick one up. When I got home I went straight for the garage to test it out. After honing the cylinders it seems that there were no cracks or grooves along the cylinders walls. I checked the ID of each cylinder which they all came in under the service limit ( 2.345 - 2. 348 ).
Pulled the Pistons and checked the end to end gaps , the service limit is .028 , the top rings were .024 and the second rings were .021 so I may just go with what I have or should I look into ordering a new set of rings since the cylinders have been honed?

rb550four · « **Reply #40 on:** March 03, 2015, 06:35:43 PM »

While you are already there and the bore is clean, within standards, why wouldn't you go for rings? I know I would, if just for piece of mind at least for sure, and wouldn't it be nice not to have to do it again anytime soon.

Icefire · « **Reply #41 on:** March 04, 2015, 07:06:04 AM »

I have taken your advise " piece of mind " and have ordered a set of rings. No sense waiting until the project is done and then realizing that I should have !!

JimJamerino · « **Reply #42 on:** March 04, 2015, 11:31:22 AM »

And so it begins... "As long as I'm in it this far, I might as well..." It can get expensive very quickly, but it'll be much easier on the mind when you're riding when you know exactly what has been done, when, and how.

SOHC4 Cafe Racer Fan · « **Reply #43 on:** March 04, 2015, 12:15:38 PM »

Plus, new rings are not that much.

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Author Topic: Icefire's 79 CB650 Project (Read 5855 times)