Two head gaskets on a 250R

[slowride]

I picked up a 84 250R a couple of days ago and the guy I got it from did a rebuild on it 10 years ago. He said that he maybe put 5 hours on it and it has been sitting for the most part unridin ever since. The day I went to look at it he said he hadn't even started it in 6-8 month's. Because of this web site I asked if it had been bored, new ring's, pistons, head work done all that. So here we go. Stock piston with nos Honda rings the cylinder was good so he honed it. The cylinder head was re-cut and shaped the chamber and because of this he said he had to put 2 cylinder head gaskets to get the piston to cylinder head clearance. The thing starts up no problem will pull the wheel off the ground without even going WOT but the problem is the cylinder head gasket is leaking after it gets warmed up. I have never heard of 2 head gaskets being used and will I even be able to get it to seal. Idles fine and I haven't drained the old fuel he had in it which is mixed 20:1. If you watch where the gasket is you can see what look's like oil boiling out. Any suggestions would be very helpful and appreciated.

[prometheus]

The only reason he put two head gaskets on it is because the bike has been rebuilt more than once and the head has been decked 2 or 3 times and wont clear the piston or he had it decked and they screwed up and took too much off. Either way two gaskets is shitty work and not proper way to fix it. Needs a new head. There are head spacer kits but not sure if they work for a 250. I've seen them done on car engines.

[slowride]

ah crap that is not what someone wants to hear. So don't even try to reseal with two gaskets try to find a new head? If that's the case where do I even begin to look for a new head? Does that mean I'm going to have to redo the cylinder with a bore kit since I'm changing the head?

[elvetost]

Before you start looking for a new head, have a good long look at the head bolts, see if they are torqued down properly.
It may just be loose bolts on the head this..
I have used 2 head gaskets sandwiched before and they seal pretty good..
Another solution to this could be to use 2 gaskets at the bottom of the cylinder. This will raise the cylinder and hence you may get away with using a single gasket in the head...
Not familiar with your bike, never seen one, let alone work on one, BUT as I said I have done this before and it works.
Another solution would be to find (make?) a head gasket with the correct height to make it work.
Hope this all makes sense man. Good luck with it!
Cheers,
Chris

[slowride]

Before I did anything the first thing I did was check the torque setting on the bolts. Yes 2 were lose and it didn't solve anything. I was trying to avoid tearing it apart any further than I had to because it is not leaking anywhere else. I have already ordered 2 nos Honda copper head gaskets and will give them a good spray of permatax copper coat and see if I can get it to seal. I like the sound of making a one piece gasket but don't know about how to do it. Thanks for the help much appreciated. This web site is great!!!!!

[elvetost]

Hello again.

There is gasket material of all sorts in various thickness available in large rolls at any decent auto/parts store.
The materials available vary a lot and there is permanite, paper, copper etc so I am pretty sure that with the old gasket in hand you could get something to match.
A good set of gasket punches is necessary to be able to do this.
It aint hard, just select your material and thickness and scribe the old gasket on the new material and cut away! Might take you a try or two if you haven't done this before but it is definitely do-able...

If you did find that there were loose bolts on the head, then it may well be that was the reason it did not seal. Because of the improper clamping of the head on the block, over time, carbon buildup, dirt, grime or what have you could have got in between the 2 gaskets and if it did, no matter what you do they'll never seal.

If I was you and since you got the new gaskets on order, I would take the head off the bike and have a good long hard look at what is what. Check the deck height, the condition of the head etc. Then if all seems correct I would try the 2 new gaskets (if indeed they are both needed, you never know until you check it) and as you said use the permatex copper coat stuff (good stuff btw, I really like most permatex products..) and see if it works!

Good luck man!
Chris

[slowride]

Thanks I really appreciate the info and will pull the head and check everything out. The new gaskets should be here soon so I will just plan on putting them on after I have checked everything else out first.

[prometheus]

I used permetex copper sealant on a car head gasket once. It worked OK but is very messy. Use latex gloves. After a good inspection of the head and cleaning the mating surfaces you may not need two head gaskets. I've seen all kinds of crap people do that is not necessary. He may have thought since he decked the head he needed two gaskets which is not always the case. Let us know what you decide to do.

[slowride]

Will do. I pulled the head off and one of the gasket's look's like a Honda copper gasket that is .020 in thickness the other one is a homemade gasket out of aluminum that is .040 in thickness. So I was like wow .060 worth of gasket. My buddy at work told me to start by putting just the copper gasket on and setting the head back on and turn the motor over by hand and see if the piston hits the head. I am in the process of finding some copper in the thickness of .060 just so I know I will keep the compression the same because I know if I reduce that number to much it will increase and will have to change the type of fuel I'm running.