Topic: Tools needed to replace head gaskets/ top end gaskets, and advice please

[manjisann]

I have read a few posts on the subject and the one in the FAQ about the great head gasket caper. My bike is leaking oil, probably because of one of the little o-rings that is leaking. I am currently gathering the tools and parts so I can redo the top end seals and such. The posts answered a lot of my questions, but left a few, so here they are.

Do I need 4 piston ring clamps, or can I do it with just on. I assume I am not removing the piston head from the shaft, just pulling the cylinders off, I am wondering if anyone can shed some light on how I get the pistons back in the cylinders as won't they all be at different heights?  I read on a different forum of some people using plastic zip ties to keep the rings in place, and once piston and rings are in the cylinder, you carefully cut the zip tie. Has anyone here tried this?

Also, while I am in there, it recommended replacing the cam chain, is this hard to do? I assume I use a chain break to remove the old one and rivet the new one in with a chain riveter.

And since I have it all apart I want to replace all the o-rings and stuff that usually wears out and causes oil leaks. So, should I replace the valve guides, or just the valve guide seals?

Is there anything else I am forgetting? Any advice?

Thanks

Brandon

[nippon]

Hello,
in order to get the pistons back into the sleeves I did not take any ring clamps.
I just have used two ends of a ruler in order to press the compress the rings from both sides, as you can see.
Take your time for the job!
Make sure, that the ends of the rings are in the right position before you are going to put them back in the cylinder sleeves.
BTW, a ruller works greeat to lower the heigth of the cylinder step by step. (see pic).

If you have to replace the valve guides depends on the milage of the bike. You could measure them.

To replace the cam chain is not a biggie. But a manual would help for adjustments.

Hope it helps a little bit. If you need more detailed informations, please let me know.

Oh, I just have forgotten to write,.... I would oil the sleeves a little bit.

nippon

[andy750]

Beautiful photo Thomas (as usual  )!

cheers
Andy

[turboguzzi]

Gee... sounds like the typical case of doing much more work than you realy need just to cure those leaks am afraid.


is it a 500-550-650? These are prone to leak between head and cyl block, but you just need to remove the head and can leave the pistons in peace.

Dont know the 750 that well but I think the same logic applies.

Give the motor a good cleaning and then try identifiying were the oil is coming from before going so deep. You'd only need to pull the cyl block out if the leak is between the cyl block and crankcases.

I wouldnt say that "To replace the cam chain is not a biggie".
you dont need a breaker, you can grind off one link with a dremel, but to rivet the master link with the engine in place you have to know what you are doing. I've done that but it's not exactly begginers stuff.

my 0.02
TG

[manjisann]

Sorry, shoulda mentioned. My bike is a 73 CB500 K2 with about 22k miles on it. I realize I don't necessarily have to do this, I am doing it as much to learn more about how the bike goes together as anything else.

Nippon, thanks for the pics and the explanation. Took me a few minutes to figure out what you were showing me, but that is a brilliant way to bring it down bit by bit. A few more questions about some of the finer points.

I just have used two ends of a ruler in order to press the compress the rings from both sides, as you can see.

Do you mean you place a ruler on two sides of the rings and then pull it together to compress the rings, and once compressed lower the cylinder until the ring slides in? Sorry if this seems like a silly question, just want to be sure I understand what you mean.

Take your time for the job!

  That is why I am trying to plan it all out now, rather then just before I am going to do it.

Oh, I just have forgotten to write,.... I would oil the sleeves a little bit.

Again, sorry, kinda a noob question, but the sleeves are what the pistons are actually sliding into right? Can I just use a very light coating of new motor oil?

Make sure, that the ends of the rings are in the right position before you are going to put them back in the cylinder sleeves.

I assume the ends should meet up square and pinch shut, is this correct? Or are you referring to their position up and down the piston?

Gee... sounds like the typical case of doing much more work than you really need just to cure those leaks am afraid

  That's me. I don't believe any of the gaskets themselves are leaking, I am pretty sure it's just some of the oil passage o-rings as its mainly on the front left side when sitting on the bike. I realize I could probably get away with riding the bike several thousand more miles with no ill effects other than a top up on oil here and there.

I am doing this as I want to learn more about fixing this bike, and I am going to fix it up and paint it some so I wanted to fix this pesky leak. Besides, it has few very very minor leaks in some other spots so I figured I'd just replace all the gaskets and o-rings while I was in there. I figure if I am slow and methodical and take lots of pics and put things in labeled baggies, I should be able to do it. I don't want to say it sounds easy, cause it doesn't, but I think it's within my ability (famous last words.)

You'd only need to pull the cyl block out if the leak is between the cyl block and crankcases.

I have read this a few places, but I have also read that you can jiggle the gasket loose between the cylinder block and crankcase, and if I am going down to the valves, this doesn't seem like much more work. Especially not when compared with doing it all without changing that gasket only to put it together and find out I jiggled the stupid thing loose.

Besides, I want to take detailed photos and post them here for others to use. It's my way of giving back to the forum for all the awesome help I have been given. 

As far as the cam chain goes. Can I remove the old rivet, wire the new chain to an end of the old one, pull it through the crank case and out the other side and rivet the new one together?  How does one get the new cam chain looped through the crank case without opening it?

[turboguzzi]

Hei Man

If it's a 500 then 99% those are just the stupid o-rings between head and cyl block.

With 22K I cant believe that your bike really NEEDS new guides, cam chain or even valve seals.

Know the saying "if it aint broken"? So if you just want to learn some mechanics without doing too much harm to your bike (which sounds like it's fine other than the leak) I would just get any old motor (or a CB500's if you must...) and play with it.

And yes, that's how you fit a new cam chain, by linking it to the old one. But if the master link drops inside the motor while riveting it, or you break a ring while getting the pistons in (easy) dont say we didnt warn you :-)



TG

[manjisann]

Are there only 2 of these o-rings, I am trying to be sure I know which ones I am looking at. I have a complete gasket kit, just want to be sure I know which are the problem ones.

With 22K I cant believe that your bike really NEEDS new guides, cam chain or even valve seals.

So, Turboguzzi, going with your "If it aint broken" wisdom, can I just remove the cylinder head without removing the valves and such and as long as I am real careful to not upset the cylinder block I should be fine, is that correct?  That would greatly simplify things. And I suppose I should reign in my academic desires, and remember the one important reason I bought this bike, to ride it  . I will also scrap the cam chain change, unless when I get in there it looks hashed. I will just have to keep my eyes out for a fixer upper bike in the papers.

Do have a preferred method for getting the cylinder head apart without disturbing the gasket that is between the crankshaft and the cylinders?

Thanks again all for your wisdom and time!

Brandon

[fastbroshi]

   If you're going after those o-rings, the barrels do not have to come off.  The cylinder head and rocker cover/rocker assembly will come off while in the bike, unlike the 750 where the engine has to come out.  Just make sure when putting the rocker cover back on you back off the rockers' adjusters and fix them in the up position with some rubber bands to prevent bending a valve.
   The cam chain tensioner does not have to be disturbed. 
   As for tools for scraping the gaskets, you'll have to get creative around the studs and pistons.  Gasket remover is a big help here.  Be careful not to nick the gasket surface up.  Get yourself a bunch of razorblades and a good gasket scraper with the screwdriver type handle and go to town.

[bryanj]

The barrells do not have to come off but if you dont the o rings in the base will start leaking later.
Your original question about tools needed
(1) A MANUAL---PREFERABLY HONDA
(2) An impact screwdriver
(3) a 3/8 drive socket set---preferably six sided
(4) A quality, accurate, torque wrench covering the appropriate range
(5) Sealable plastic bags
(6) Gasket scraper
(7) Metric combination spanners
( Assorted Screwdrivers

And most important GOBS OF PATIENCE and CARE

[turboguzzi]

Yes, you can do it without disturbing the cyl block.

posted before the wrong solution, aplicable only to bikes that have bottom cyl studs too.... ooops/sorry/forget it.

never had that many problems wrigling the head out in my sohc's, a good place to blow some mild hammer blows with is the lip above the exhaust ports.

Bryanj, the bottom oliways go through little tubes and being further from the hotest area doesnt dry out the o-rings. dont remember seeing leakage cases on the bottom ones, but I might be wrong.

TG

[manjisann]

posted before the wrong solution, applicable only to bikes that have bottom cyl studs too.... ooops/sorry/forget it.

If I understand you, and have read the blow up diagrams right, the bolts are threaded into the crank case and the cylinder and cylinder head slide on and then are bolted down, is this correct?

And most important GOBS OF PATIENCE and CARE

I plan on taking my time. I realize the first time I do something it will take me 2-3 times as long as it otherwise would.

So it sounds like I should be OK if I remove the cylinder block and replace all the o-rings and gaskets in that area, so long as when I put it back on I am super careful to orient the ring openings properly (got this from the clymer manual, anyone have any additional wisdom with regard to this) and I don't force the rings.  Nippon's idea should make it easy to reinsert the rings and piston through the cylinder in small intervals.

Since I am going to have the top end off, I have been thinking I might want to repaint it silver as some of the parts are worn and my ultimate goal is to make it look as nice as possible without a complete and total stripdown. So with this in mind, I have another question. Can I repaint the Cylinder Head (sorry if I am using the wrong terms, its the part with the valves in it) with the valves still in it, as long as I am very careful to mask and paper off the parts with the valves, or am I really better off removing the valves and cleaning it all really good. If that is the case, I will bag each valve assembly separately and label which cylinder it goes to and whether it is intake or exhaust, and as long as I have a valve spring remover tool I should be OK right?

Will 500 degree engine paint be OK, or will it burn off? Also, will that cause the engine to not properly cool?

Thanks all,

Brandon

[bryanj]

when you pull the block an remove the dowels that have the oil restrictor jets in them BE CAREFULL that NO crap goes down the holes or you will block the jets and sieze the cam

[manjisann]

when you pull the block an remove the dowels that have the oil restrictor jets in them BE CAREFULL that NO crap goes down the holes or you will block the jets and sieze the cam

  and surgeons think they have it bad. Thanks for the warning.

Brandon