1mm oversized pistons, crank req.

[Stumac]

In case you want to get prices here are the part numbers

Pistons
standard 3TJ-11631-01
+ 0.5mm 3TJ-11636-01
+1mm 3TJ-11638-01

Rings
Standard 3TJ-11610-00
+0.5mm 3TJ-11610-20
+1mm 3TJ-11610-40

[buzzawak]

In case you want to get prices here are the part numbers

Pistons
standard 3TJ-11631-01
+ 0.5mm 3TJ-11636-01
+1mm 3TJ-11638-01

Rings
Standard 3TJ-11610-00
+0.5mm 3TJ-11610-20
+1mm 3TJ-11610-40

Hi Stumac, Thanks for the info, I think I have a 1WG engine, but I am not sure my bike is a mis-mash of parts from different models.

[buzzawak]

The 1mm overbore is the most expensive way to do this as you'll need new pistons from Yamaha.
I was thinking the 560 mod would work well ... of course I won't tell anybody you've done it as long as you don't. You'll need the 3HE 600 engine (Yours is a 1WG 3en1 isn't it?) and you build the top end barrels and pistons onto the 400's gearbox crank and conrods. You'll need gaskets, it would be best to give the bores a hone and have a look at the rings.

It's more likely the cam chain ... or the tensioner's got stuck.

I think you right Evil, the 560 is the way to go.
I will have a look at the cam tensioner tonight. I take it I can remove it without fear of some thing dropping into the case (unless some thing is broken).

[Evilchicken0]

It should just unbolt and come out. Be careful with the gasket.

[Thunderbike_steve]

Why not put the 600 crank in too and make it a 600?
The 3he crank bolts straight in, even uses the same crank seal. All you have to do is use the 600 clutch too as it has the primary drive to match the 600 crank.

[buzzawak]

Why not put the 600 crank in too and make it a 600?
The 3he crank bolts straight in, even uses the same crank seal. All you have to do is use the 600 clutch too as it has the primary drive to match the 600 crank.

So if you use the 600 crank I take it then you don't have to have the spacer for the heads ?

[Evilchicken0]

It takes you into splitting the crank cases ... makes a possiblr weekend job a bit more involved .... you'll be messing around with plastigagauging the crank shells and ordering more parts.
It's 40cc more - which is nice - but your 560 will be a short stroke so you'll get the higher revs.

[buzzawak]

Following up on the 560 conversion. I know I read a thread with instructions some where. I am after
the conversion that used a plate between the case and bores to maintain the same stroke length
as the 400. Anyone have a link?

Thanks in advance.

I knew I should of book marked it at the time !

[hunter]

That's the 660 conversion.

[Evilchicken0]

That's the 660 conversion.

????
560 coversion ?
You use the barrels* pistons head + cams* from a 600 and effectively create a short stroke 560cc engine. The 600 has a longer stroke so you'd have to change the crank to get the extra cc's ... which would be a longer job and you'd have to renew the crank shells making it not worthwhile, (you'd just a 600 motor instead).

* maybe - check out FZRFiles webpage for the how to guide