looking for .30 over pistons for a 1986 xj700 maxim x usa

I had some engine work done to my xj 700. What I found out is that number 3 cylinder is becoming egg shaped. What the technician told me was the I or the engine was 3thousanths out of round. He stated that he was unable to find any new pistons that where .30 over.
So I had him just hone and put new rings in.
My question to anybody is are pistons .30 over available?
Or what could be causing the one cylinder to be out of round when the other three are good?

 

Good luck ---- got lots of $$$$$?!???!???!

 

that's what I was thinking. Looks like I may need just a new motor.
Do you know if a 750 xj engine pistons may work?

 

It's easier to find low-mileage cylinders.

 

OK I not very mechanically inclined- what your saying is that the cylinder head detaches from the lower block. If this is correct I just need to replace the cylinder head than?
Somewhat like a car I guess except on a motorcycle the cylinder head is where the pistons run up and down?

 

No (but you'd be correct if this were a very-early motorcycle engine, which had integrated heads) The cylinder head is where the combustion chamber and valves reside. The cylinders are a seperate assembly from the crankcase and can be swapped with the engine in the frame.

You need a service manual; two really. The Haynes and the Yamaha.


The head (camshafts and valve cover removed):


The cylinders (non YICS)


The crankcase ( bare; viewed from the left-rear)

 

The K-moe manual is so much clearer than the Haynes manual

 

You do mean .003" right?
Although I have never done it; replacing a piston that is .30" over sized sounds like a David Blaine stunt.

 

Thank you for your time and yes I meant .03o over.
If I can fine a head than I should be good.
K-moe repair manual is available where?

 

I'm sure there are several aftermarket custom forged piston manufacturers who could easily make a set of pistons for an overbore. I bought custom pistons, built specifically for my Boss 429 Mustang engine many years ago, and we could specify dome height, valve cutouts, pin size, etc. You would probably need to send them an OEM piston to simplify the design process.....
It would need to be a custom piston maker that speaks metric, and, preferably, motorcycle - I'm sure someone does this.
Cruiser

 

nevermind.

 

There are. And a set will cost more than an entire used XJ. Simply not enough demand for it to be cost effective to make a full production run. There is also an inexpensive big-bore kit for the 750, but it leaves the liners a bit too thin for my blood.

 

Right here.....

 

For free (though I am willing to accept free-will beer or whisky donations).

 

Has anyone developed whiskey Beer? Think of the time Savings!

 

That would be called a boilermaker, and it makes time completely disappear.

 

Burp... where am I?