Topic: head gasket

[comcrx]

where is a good place to buy one?

I am starting to get a little oil around my headgasket. I don't want to do a rebuild, or really even 'freshen up' the motor until the winter, but it would be nice to have a new gasket just in case my bike doesn't make it til then

thanks,
andy

[Jerry Rxman Griffin aka MuthaF'er]

Andy,

Perhaps one of the guys that has a big bore will have a leftover stock size from a rebuild that you can get reasonably.

[apormarkos]

if you're taking off the head you'd better replace the little o-rings between the head and the cylinders.  they're the usual culprit for those oil leaks. 
oh, forgot to mention... i got an athena brand gasket kit fro my 550.  pricey, but good i guess.  it was missing one of the o-rings i speak of.  honda still stocks them.  i would guess they still have them for the 750 as well.
apor

[scondon]

 I agree with Apor. If you're pulling the motor(CB750) to change a head gasket you will want to replace other seals as well. A complete top end gasket set will run between $60-$70, I think, and are readily available in the aftermarket. If you'd like to have an extra head gasket on hand I've got several left over (Good call Rxman )

[Jonesy]

The genuine Honda head gasket for the CB750 is about $75. If you remove the head, you'll want to do the base gasket too, along with the o-rings that seal off the oil galleries. Any O-ring you pull out of that motor will have flat sides after being squished and heated over 30+ years!

[comcrx]

well, I figure I've got another good two months of riding season left, so I'm guessing the smart thing to do would be to go ahead and fix it.

scondon I'vce sent you a PM

I'm assuming these o-rings are just the generic kind I can get at the hardware store, right?

I just don't want to pump a bunch of money into something I'm going to turn right around and take apart in a few months. I would go ahead and do it now, but it would cut into riding time, and money isn't quite there to do it the way I want

[Gordon]

I'm assuming this is your 750?  Have you considered the fact that you're going to have to pull the engine to do any kind of top end work?  If it's not a major leak, you might be better off waiting until you have the funds for the whole top end kit and take care of it during the off season. 

[scondon]

 Heres what's needed for a 76 750K.

 4 oil galley seals, 8 knock pin seals, 4 oil pressure jet seals, 6 rubber pucks(under the cam towers), cam breather seal, Cam chain tensioner gasket, base gasket, valve cover gasket, am I missing anything?   All this stuff will need to be replaced if you break your engine down to change out the head gasket. Otherwise you'll end up with even more leaks when you reassemble, IMHO.

  If you're only experiencing light "weeping" around the head gasket area I would leave it be as this is common. If it's leaking a lot and blowing back on your pants legs and the rest of the bike then I can see you wanting to do something about it. Due to years of heat cycles and wear it is not gauranteed that your motor won't leak even after new seals and gaskets are put in. Rebuilding a "leak free" motor takes a lot of work and possibly a bit of machining. Possibly new cylinder studs as well.

[comcrx]

yep, I realize that the engine has to be pulled. like I said before, I am already planning on tearing the top end apart over the winter, so I will take advice and leave it be for now.
 its not even close to spraying back on my pants leg or anything, just alittle weepage on one of the fins around #4. I've also noticed a little smoke coming from the breather tube, but I'm not sure if thats from a failing gasket or just worn out rings.
 i think the engine has around 25K on it, so its about time to do this stuff anyway. I just would like to be able to afford to do an 836 kit and some head/cam work while I'm in there

thanks for the help guys,
andy

[Yas001]

My 78 CB750F is under the process of head gasket replacement. I got the parts from http://www.siriusconinc.com/default.asp
reasonable price...

[Stevearino]

Head gaskets are expensive.  Here is a great place in Indy.  Tons of recycled parts, good selection of new parts, and good advice.  Rob knows his #$%*.  Worth a visit if you are through these parts.  Remember, even diamond mines are dirty places.

[carlbeaver]

Try Siriusconinc.com in Canada.  They have ots of CB parts at reasonable prices.  A complete gasket kit for a 78 CB750 cost me $69 plus shipping.

Carl

[jdpas29]

my bike is weeping over on the left side near the exhaust manifold.  i'm guessing that's the head gasket area.  it is enough so that it comes back on my leg and ruins my pants and stuff.   the bike runs like a dream though and i hate to take it apart just for this.

my question is...  could i check the torques on the bolts that hold the head down on that gasket without pulling the motor?  i was just thinking that maybe in the 30 years this bike has been running that these bolts may have loosened a bit.   

[OldSchool_IsCool]

Doubtful that a re torque will fix the leak. 

To confirm leak location (could be the tach cable if it's on the right)
- clean the engine
- when dry, spray foot powder on the suspect area
- run the engine
- the white powder will turn black at the leak site
- rewash engine

To control the leak (assuming it's between fins)
- cram a rolled up paper towel between the fins over the leak
- short length of cotton clothes line works great too
- replace when saturated
- wear rain pants, chaps or nylon wind breaker pants if you really need to protect your clothes

[amemoryoncelost]

 WOW! Very refreshing to read these past few posts. I thought mine was leaking bad, has a bit of oil on the left side leaking out, but it doesn't get on my pants or anything. I thought I was gonna have a blown engine on my hands. I will be doing a rebuild this winter though, hopefully I can spend enough time on it to get it as leak free as possible...

[rhinoracer]

I used the Honda OEM so I have a leftover Athena head gasket from the gasket kit. PM me if interested.