Temporary head gasket repair?

[freedomlives]

I blew the head gasket on the Rotax 2-stroke motor of my Goldoni mower yesterday. It may have over-heated due to debris under the cover from the previous owner (which I should have done a thorough check after buying), or maybe just the nuts holding the head on were loose after 30 years. A new gasket isn't that expensive, just 8€, but in Austria, 600km away, and the store doesn't have shipping to Slovakia-- I've got a friend who will go buy it and mail it to me, but that may take a week. But I'd really like to finish mowing the hay with this mower, because it gets it done at a decent pace of 1 acre per hour. The mower it is replacing, which fortunately I haven't sold yet, given the present disaster, only does 1/2 acre per hour.

Given that the gasket only has a small place where the gases blew past and eroded the metal, I'm wondering if there is anything that could have a hope of temporarily filling that gap, that might have a hope of holding up for another 3-4 hours of use-- like that sort of goop used to repair mufflers and exhaust pipes? I've got JB weld as well, though obviously I don't want that it sticks the head together, but I suppose if the surfaces anyway have a film of oil on them, the JB weld isn't going to adhere to them.


(Funny orange color is melted plastic of a tool box that got hit by the hot air from the hole-- the engine kept going at full throttle, I only noticed because I stopped to inspect whether something was lose on the cutter bar, and then it wouldn't start again.)

 

[TemporaryKubotaOwnerMark]

I'd be tempted to give JB Weld a try. I know, I know, that can't possibly hold up to engine compression.

But if you can make an entire head out of it, maybe it can.

Clean the affected area with brake cleaner, let dry, then fill with JB Weld. Once it's cured, file it flat, and reassemble things as usual, making use of your favorite head gasket spray.

 

[freedomlives]

Hmm... I don't have a favorite head gasket spray. I didn't know there was such a thing. I'll clean the damaged area of the gasket and apply a thin layer of JB weld there then, and rub a bit of oil on the head and cylinder, very thin to keep it from sticking to those places and put it back together. Since its Sunday tomorrow, it can have the full 24 hours plus some time to cure.

 

[jcraftenworth]

I recommend jb weld over bailer twine, anyday!

 

[TemporaryKubotaOwnerMark]

Hmm... I don't have a favorite head gasket spray.

Right here.

I'll clean the damaged area of the gasket and apply a thin layer of JB weld there then, and rub a bit of oil on the head and cylinder, very thin to keep it from sticking to those places and put it back together. Since its Sunday tomorrow, it can have the full 24 hours plus some time to cure.

You need to apply it, let it sure, file it flat, and THEN reassemble.

 

[freedomlives]

I just slopped it on and tightened the head back down. I ran it for about 15 minutes today without a problem, but a screw on the bottom of the mower mechanism keeps coming loose and falling off, which probably means some internal piece is absent. so gotta take that apart...

 

[freedomlives]

I just slopped it on and tightened the head back down. I ran it for about 15 minutes today without a problem
View attachment 512227

Didn't last long-- not even long enough to drive it to the field that needed cutting.
It occurred to me, looking at the headgasket, that it looks a lot like the gaskets used on car exhaust systems-- and what do you know-- I picked one up the right diameter for 2€ from the autoparts store! Hopefully will last a bit longer-- 2 more acres left to cut.

 

[mrmikey]

Get a piece of thin copper, cut the piston hole with a hole saw, bolt holes with a regular drill and anneal it. If you find it hard to cut without it going all egg shaped, clamp it between two pieces of plywood and drill the bolt holes first and use those hole to clamp it together............Mike

 

[freedomlives]

Get a piece of thin copper, cut the piston hole with a hole saw, bolt holes with a regular drill and anneal it. If you find it hard to cut without it going all egg shaped, clamp it between two pieces of plywood and drill the bolt holes first and use those hole to clamp it together............Mike

Thanks. I'll try that if these exhaust gaskets don't work.

 

[freedomlives]

(Original material seems like 3 pieces of aluminum sheet metal stacked actually)