I just installed a 70cc airsal on my 77 newport.

I have it running nicely at idle. Low and steady.

Before I throttle, I spray for leaks.

It leaks at the head base and carb.

I replaced those gaskets twice so I'm assuming I'm doing something wrong.

Starting with installing the cylinder gasket.

I then install the cylindar

Head gasket and head. (Piston ring is in place)

I tighten with a sockit (not ratchit) with my fingers. "X"

Then install the pipe (snug on the cylinder and lose at the bracket)

I then proceed to torch the head gasket "X" to a fair snug.

Replace the carb, spark plug...

(Turn the petcock to "on")

It fires right up with slight throtle and maintains a steady rpm.

The head leaks a bit, the cylinder leaks a bit more abd the shivy leaks the most.

How do I install the gaskets and propperly secure potential air leaks?

Please pardon mis spellings, they are not significant.


Re: gaskets

I always oiled my gaskets before putting them on. I don't know if you have too, But my pops always did it. Don't know, just my $.02

Re: gaskets

Joshua Wood /

Ok. I can certainly oil my gaskets, I'm just not sure that will fix the problem. I'm definetely new to mopeds and learning as I go. Any suggestions are appreciated.

What else could I be doing that would prevent these gaskets from sealing properly?

Re: gaskets

Probably Fred /

Put the exhaust pipe on after you install the cylinder/kit

Did you case match? Do you use washers on studs? Did you remove all of the old gasket. Are the nuts stripped?

I can't why people have problems with this simple procedure .

If the nuts hit stripped stud threads or they tighten on the end or the thread add washers to get into good thread or get new threads.

Also install the pipe with no forcing. Put the pipe on the cylinder then make a rear mount if you have to.

Make sure you start over again with new gaskets.

Post pictures of surfaces, studs, used/bad gaskets or problem parts

So we know. I take the treats "the good one" 70cc gasket set( for example then I match the gasket to the cylinder with a razor knife then I match the gasket to the engine case with dremel ( another story)

Then I put the Piston on, then base gasket over the studs, then the cylinder (don't damage ring) then the head gasket then the head then washers then nuts then hand x tighten then torque 7-9 lb but mostly just by hand with a small 1/4 drive ratchet. I did this dozens of times so I could tell how tight.

On some builds I have someone turn over the engine when I torque in X fashion . Never in 30 some years did I have a leak when done. It's got to be something simple or dumb your doing wrong or a nub on the engine case hitting the cylinder cause it's very easy to install a top end with no leaks

Re: gaskets

I second oiling the gaskets.

If it leaks between the head and cylinder (usually there is a metal head gasket here), check that your head is perfectly flat. You can buy a piece of glass, put some oil on it, then put the head on it. If you look up at the glass, you can see bubbles if the head isn't meeting the glass perfectly. If that's the case, you can do this. (If it isn't leaking between the head and cylinder, ignore this part).

Also, get your head torqued down (the X pattern is good) completely before installing the pipe. It just seems like having the pipe weigh the cylinder down before it's completely tight would throw things out of whack.

As for the carb leak -- what kind of carb do you have and where is it leaking? Where it joins the intake? Where the top of the carb meets the carb body? Somewhere else?

Re: gaskets

Joshua Wood /

Thanks for your input, ken and linda.

I discovered a small leak in the head gasket. (Not concerned with that as much)

As for the carb, it a dellorto SHA15150.

(Ill attach a photo of it)

I'm thinking in need a new shivy. It leaks where the intake meets the carburetor.

My biggest concern is the base gasket. I can't get it to seal properly.

If the case is not proppery sealed, would that cause a base gasket to fail? Is it possible that the fluid is leaking into the cylinder and through the gasket?

I substitute 10w40 for transmission fluid.

Do I just dip the gaskets in oil?

Re: gaskets

Joshua Wood /

Forgot to attach this.

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