head gasket

[mopivo]

I have a 95 bullet 500cc.  I recently did a valve job.  I torqued the head to the specs, and can not get a good seal, it's leaking oil around the seal.  Anyone have any ideas?

[deejay]

If you don't get it just right, headgasket leaks are common from the oil return passages on these bikes. Mine has weeped oil since new from the exhaust side passage. While I am living with it for the riding season, I will be fixing it during the winter months by replacing with a new gasket and applying a SUPER THIN layer of gasket maker sealant. I haven't decided if I am going to try a copper gasket or a stock one... hell I may even try to lap the head and not use a gasket at all.

Good luck.

[mopivo]

Thanks, I tried that earlier today and it seems to have worked, or helped.  I'm going to have to do it again, I need to order a new gasket, but the copper gasket spray really made a difference!

[t120rbullet]

I have a 95 bullet 500cc.  I recently did a valve job.  I torqued the head to the specs, and can not get a good seal, it's leaking oil around the seal.  Anyone have any ideas?

The older ones that I have seen have a small depression in between the pushrod tunnels on the head.
I cured both my 95 and my 99 by lapping the head down on a piece of glass until it was flat all the way across. I used a medium grade valve lapping compound and it took it down pretty fast.
Then I reassembled the head with the stock gasket with a layer of spray-a-gasket on it.
CJ

[deejay]

anyone have a step by step guide to lapping?

[dewjantim]

anyone have a step by step guide to lapping?

First- get a bowl of water, Second- stick out tongue, Third- start lapping......Dew.

[RagMan]

anyone have a step by step guide to lapping?

First- get a bowl of water, Second- stick out tongue, Third- start lapping......Dew.

  My dog makes a mess doing that. She needs to refine the technique.

[deejay]

anyone have a step by step guide to lapping?

First- get a bowl of water, Second- stick out tongue, Third- start lapping......Dew.

you should try harder at being funny.

[sewerman]

Lapping the head is a good idea.  Remove all the intake and exhaust so that the head spins around on the protruding cylinder.  Take small pieces of rags or paper towels and tie into a small bowtie with a small piece of string leaving an inch hanging off and put one in each head bolt hole and in the oil/push rod holes.  This will keep the lapping compound from going down in the holes.  Put compound on the head/cylinder surface AND the top of the protruding cylinder where it goes up in the head.  Cover/protect the top of the piston and the upper cylinder wall.  Now get a comfortable chair, your best beer and some good music and SPIN,SPIN,SPIN!.  It takes a few hours to get good results but its worth it and it is relatively free.  Every so often clean off the compound and add new.  When done spray each little bowtie with WD40 and pull the string to remove.  Take some long Qtips with WD40 and go down in each whole to get any leftover compound.  This is also a good time to decarbon the head, port and polish it(I did this and the old Bullet came alive) mill the head(I didd 35 over) and "adjust" ant leaks at the head/exhaust junction.  My advice to all Bullet owners is to can the stock exhaust and air filter at a minimum.  It is amazing how "choked" a stock system is.  To all the purists who poo-poo this, bug off.

[Peter]

This finally got me registered.

I lapped the head to the cylinder.

I took the jug off, removed valves and decompressor valve from the head and then lapped patiently.

After that, I spent the better part of an hour to clean the head and jug. Full sumbersion, pressure wash, kerosene, triple check.

Lapping compound is about the worst thing to get into your engine. One grain is enough to damage your rings. If some gets into the pushrod passages it will end up in your big end bearing, eventually.

That's just me, YMMV.


Peter

2003 Bullet, 535cc/8.5:1

[deejay]

why doesn't anyone mention gluing sandpaper to a sheet of glass and lapping that way? I'm confused

[t120rbullet]

why doesn't anyone mention gluing sandpaper to a sheet of glass and lapping that way? I'm confused

You can do it that way. It just adds another step to the process.  Not any faster or slower.
Clean up is still the same.
CJ

[Thumper]

I have a 95 bullet 500cc.  I recently did a valve job.  I torqued the head to the specs, and can not get a good seal, it's leaking oil around the seal.  Anyone have any ideas?

There are a lot of people who advocate annealing the head gasket. Both the Yahoo RE forum and Hitchcock's message board have had threads on this. There doesn't seem to be much controversy about whether or not do do it; just discussion on how to do it.

Here's a snippet from one thread:

Annealing head gaskets  
Posted By GeorgeE On 2007-06-05 At 15:58:56
    
Have just surfaced the head for my Super Meteor and am ready to replace . I seem to recall two variations on annealing the copper gaskets One to heat it up then plunge into water . The other to heat up and let cool down naturally . I have no experience with copper gaskets but it seems that a quick plunge in cold water would distort the gasket and with only 22 pounds torque( or thereabouts ) recommended it would seem the flatter the better . But then again what do I know ? Thanks in advance for any help .
George
 
Follows Ups
Posted By John E On 2007-06-05 At 16:18:54
Both work but if you let it cool naturally it forms an oxidised layer on the surface where plunging into water takes the layer off leaving a clean surface, copper "work hardens" --the more you work it (bend-hammer etc)--the harder it gets--- oooh-err mister!! )
 
Posted By DaveT On 2007-06-05 At 20:11:53
I always thought that you had to quench the gasket in water to get the proper effect. A quick search and and I found this from the Proceedings of The Royal Society Volume 80 No. 535 December 9th 1907

"It is common knowledge that hard copper becomes perfectly annealed by heating to 500 C; that the heating need not be for any lengthened period, and the rate of cooling afterwards is unimportant."
 

Posted By John R On 2007-06-06 At 13:05:14
    Image Link http://

So, we should be going for 700-800 degrees to anneal copper. How does this compare to a gas flame on the cooker or a blowtorch?
 
Follows Ups
Posted By mikey On 2007-06-06 At 15:21:23
I always work around my solid copper gaskets by heating one portion on gas ring to cherry red then plunge into water
I then move to next part of gasket. It works for me.
I do not have facility to heat whole of gasket in one go.
Cheers
Mikey
 
Posted By Les H On 2007-06-06 At 16:32:21
Bright yellow 1093°C
Dark yellow 1038°C
Orange yellow 982°C
Orange 927°C
Orange red 871°C
Bright red 816°C*
Red 760°C*
Medium red 704°C*
Dull red 649°C
Slight red 593°C

* Looks like any RED colour will do then!

----------------------------------

Here's some more discussion:
http://www.xvo73.dial.pipex.com/ht/cuanneal.htm
http://www.britbike.com/ubb/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=11;t=002278;p=1

Matt

[Peter]

why doesn't anyone mention gluing sandpaper to a sheet of glass and lapping that way? I'm confused

My cylinder head wasn't flat at all and because I lap with small back and forth movements I need to start with a flat surface. The spigot also wasn't quite perfect so I flattened it as well.
In a pinch, I would lap by spinning it until everything is flat and then finish up with back and forth.
The problem with spinning all the way is that your may get scores all the way round, including the oil passages. So I just take my time and contain the imperfections to small spots.

You'll see what I mean when you start lapping.

Peter

[FiferWD]

[

Here's a snippet from one thread:

Annealing head gaskets  
Posted By GeorgeE On 2007-06-05 At 15:58:56
    
 
Posted By DaveT On 2007-06-05 At 20:11:53
I always thought that you had to quench the gasket in water to get the proper effect. A quick search and and I found this from the Proceedings of The Royal Society Volume 80 No. 535 December 9th 1907

"It is common knowledge that hard copper becomes perfectly annealed by heating to 500 C; that the heating need not be for any lengthened period, and the rate of cooling afterwards is unimportant."

Speaking with little authority, and less experience, I do a bit of flintlock rifle and pistol construction and cast some of my own brass furniture.  Now brass may be different from pure copper, but I have been taught that it is hardened by heating and air cooling and annealed by heating and quenching -- the opposite of ferrous metals.

[dewjantim]

anyone have a step by step guide to lapping?

First- get a bowl of water, Second- stick out tongue, Third- start lapping......Dew.

you should try harder at being funny.

That is about as funny as I can get without getting my post deleted........Dew.