GL1000 1976 - Head gasket

[nicdes]

So nicdes, let me ask you on your cars head gasket,,,,,, was it a “Saab” story ? Sorry couldn't help myself !

it finally has been a happy ending story but it went thru lot of trials and sometimes close to brain gasket failure !

[redglbx]

Nicdes,

[nicdes]

Hi,

Some image of the radiator :

Back before :



Front Before :



Detail :



Back after :



Front After :



The tool :



It has been cleaned inside. Im waiting for a new cap and new black hoses from samco.

[nicdes]

Hi,
It was a nice spring sunday afternoon here. I shall have been invited to a neighbor's birthday party. Due do my covid recovering time I stayed home. I like being alone
Here we go !

After having removed the crash bars, radiator and exhaust collectors :




Timing belts cover off :



Removing the fuel pump :



Head cover is gone :



The pulley turns clockwise after removing the belts :



Camshaft out :




Pulley cover plate :



The head turn :




The 6 bolts :



Right Cylinder side :



Piston 3 :



Piston 1 :



Head and its dear gasket - looks burnt at its center :





Lets start the left side :





The camshaft - My mistake :




Head and gasket - looks better than the right side ?





The left cylinders :



Number 4 (I am not a number) :


I think I've mistaken something with the camshafts. I shall have remove the pulley before to take it all off. Would you have suggestions to remove it now ?

Thomas

[Lucien Harpress]

Easiest way I would get the pulleys off at this point would be to use a strap wrench (or rubber strap of some sort) to hold the pulley while you use a wrench to pull the small bolt off the end. While they are torqued, they usually aren't cranked down super-tight.

That said, you may not need to strip is down any more- if it came off in one piece, no reason it can't go back on in one piece as well. You'd have to strip it down if you wanted to replace the three cam end seals (left side has 2, right only has 1. That way oil can get to the fuel pump arm/tachometer drive), which isn't the worst idea, but not really needed if they didn't leak before.

[Fred Camper]

Agree with Lucien on this one.

[Track T 2411]

I used an old timing belt wrapped around the pulley and clamped into a vice to remove mine. Personally, I would replace the seals. They are available at any auto parts store. Number is in the crossover parts list...

[robin1731]

Take a close look at the cam lobe on that LH cam. The first one from the points end. Could be the pic but looks like some weird wear on that lobe.

[nicdes]

I'm clearly thinking about replacing those lip seals.
I shall wrap the cam and put it on a vice then ?
Another pic of that cam :

20220502_111610.jpg

[redglbx]

Personally, I’d Wrap & clamp on the cam gear in the vise, not a good idea to put the cam in a vice As you can unintentionally damage the cam, clamp on the pulley.

Has this bike been sitting for a while ? I agree with Robin that the discoloration on the cam lobes is a bit weird looking. From your photo’s I say the head gasket was blown on cyl #3 between the patterns on the gasket itself and the extremely clean exhaust valve. I would also retorque the head and cam carrier after a couple of heat cycles, the bolts will move ! Make sure you use the bolt torque sequence that’s in the service manual.

Nice job on the radiator by the way ! Lots of patience there !

You should have a nice running GL once you’re all done here, Let us know how you do.

[gltriker]

I used an old timing belt wrapped around the pulley and clamped into a vice to remove mine. Personally, I would replace the seals. They are available at any auto parts store. Number is in the crossover parts list...

I like Track T 2411's method. No physical contact of the vise jaws with either the camshaft, itself, or the camshaft drive pulley

According to the official Honda GL1000 Shop Manual , the torque spec. for the camshaft pulley cap screw is 250- 290 kg.-cm , 18-21 lb. -ft.
A quick burp with an air or electric impact wrench will easily loosen the cap screw.
If one isn't available, a socket wrench or a plain old wrench will break the cap screw loose.

[gltriker]

Are you knowledgeable whether this engine has had one or both original cylinder head gaskets replaced sometime in the past?

The reason I inquire?

The photo of only 6 cylinder head retaining fasteners in the plastic container made me question, where is the 7th fastener?
The cylinder heads' gasket sealing surface and their complementing cylinder block gasket sealing surfaces do not appear to require scraping off the always very stubborn to remove fibrous head gasket material the original head gaskets are manufactured with.

[nicdes]

The L & R 7th fasteners were in place, but you are right I didn't show them in the fastener box

BYI4EuC.jpg

I don't know for a previous HG replacement, but It's possible.
The thing I know is that this bike had an engine replacement bcause bike is 76 (GL1E - 200...) and the engine is 77 (GL1E - 3.....). And also It stayed years stocked in a garage. Maybe that's the reason for the bad head gasket.

[robin1731]

The L & R 7th fasteners were in place, but you are right I didn't show them in the fastener box
BYI4EuC.jpg
I don't know for a previous HG replacement, but It's possible.
The thing I know is that this bike had an engine replacement bcause bike is 76 (GL1E - 200...) and the engine is 77 (GL1E - 3.....). And also It stayed years stocked in a garage. Maybe that's the reason for the bad head gasket.

It's possible the heads have been removed before. That 6mm bolt is not the original type bolt that was in there.

[redglbx]

Robin, yep, those look like the bolts used on the intake manifolds, they are normally just plain hex heads. Shouldn’t be a problem as long as they are the correct length.