ESE's works engine tuner

[41juergen]

Hey Wob, would that be an option for your project? Not yet solved is the design of the PV drum channel for the aux ex port..

[wobbly]

The 31K would need a PV drum exactly like the 3XV , maybe a step too far for the customer.
But he is over the moon about the results so far anyway.

[41juergen]

The 31K would need a PV drum exactly like the 3XV , maybe a step too far for the customer.
But he is over the moon about the results so far anyway.

Got it, the 3XV may not really suit as the stock 31K drums are not as wide in that area and have the bushes in the way...

[wobbly]

I see the red marker for widening the B port , what piston are you thinking of for this , the Meteor TZ350 was the only single ring pinned over the boost I know of.

[husaberg]

the Meteor TZ350 was the only single ring pinned over the boost I know of.

Challenge Accepted...

[41juergen]

I see the red marker for widening the B port , what piston are you thinking of for this , the Meteor TZ350 was the only single ring pinned over the boost I know of.

At that time it was still possible to get small customized lots (2 pieces) from Woessner (with a 66.0 mm diameter)... This drawing had the ring peg at 30° left or right of the C port, the final version had the one ring peg running over the C port.

[husaberg]

Not sure where it is pinned

https://www.tkrj.co.jp/goods/m-AY0980X-31K.php

[IMG][/IMG]

ODEL	RZ-350RR for RACE
OEM No.	31K
CODE No.	AY0980X
BORE(mm) ：Ａ	64
LENGTH(mm) ：Ｂ	72
PIN DIA (mm) ：C	16
COMPRESSION HIGHT① (mm)：D	40
COMPRESSION HIGHT② (mm)：E	36
PIN LENGTH (mm) ：Ｆ	54
PLATING	O
STROKE	2
PISTON　CODE No.	PY1280X

nz post classic allow up to 410cc or so dp Aussie rules allow over 350cc ?

[wobbly]

Thanks Husa, I have emailed them about the pin position.
I can get the Meteor wholesale , but these are even better , and can go up in size before the bore is plated.

[wobbly]

Idiots put the single ring pin in the stock position , between the B and boost port.
So sadly not a " race " piston at all.
Juergen - I had some Wossner specials made last year , 66mm for a 400 racebike , they now demand 10 off.

[SwePatrick]

Relocate the pin then.

[husaberg]

Idiots put the single ring pin in the stock position , between the B and boost port.
So sadly not a " race " piston at all.
Juergen - I had some Wossner specials made last year , 66mm for a 400 racebike , they now demand 10 off.

Buggar, Tell them what you want and the market there is for alternatives and I think you might find them quite accommodating.
I see they do RS125R Honda ones now. After all What is there to lose.
Personally I would not open with "you idiots"...
I had a look through a lot of pistons I was surprised how many MX were pinned like that
I even seen a two ring piston that had the pins in the same location with no overlap at all?

KTM200 pistons are the long enough? or available in single ring?
single ring yes not sure where pinned I have never seen one
but they do have good long rods for a Yamha twin.

[NickL89]

So here is the next interesting project , YPVS 350 classic racebike on pump gas - no deto.
This thing also has the old Yamaha drum PV , but no Aux ports - so way better than the original Banshee.
Its got a Nova close ratio set in it , so it was begging for me to go spastic on the tune.
It went thru the roof in the sim when I added the Wobbly duct and that damn weird concave rear cone - again.
I Apriliaized the porting again like the 3XV, but wont know what head to put on it until those are dynoed in the TZ250 test session.
Only domed TZ350 single ring race pistons are available from Meteor, so it will be ported , then the stock size iron bore plated to be able to keep on using that same piston size.

Hi Wobbly,

Could you share the pipe dimensions by any chance?

[wobbly]

Yea OK Husa I will very politely ask if they will do some with a 6 o'clock pin , but they havnt even bothered to reply to my pin position request after a week.

That whole ring pin scenario is a personal sore point , as when I pointed out to a reply on a forum , where some " idiot " replied that no way can you put a pin over the boost port , as the ends would immediately " catch "
I got blocked for saying he was a moron as its been done since the middle of last century by every manufacturer ( except TKRJ ) with no issues at all.

Re the pipe dimensions for the YPVS - not my intellectual property , so I have asked for the customers permission to publish.

[pete376403]

[QUOTE=wobbly;1131225537]Yea OK Husa I will very politely ask if they will do some with a 6 o'clock pin , but they havnt even bothered to reply to my pin position request after a week.[QUOTE]

Or ask if they can do pistons with NO pin and you will install it where you require

[F5 Dave]

Thing about a racebike is that you don't want to build it only once so replacement are ideally, have a set on the shelf and know that they can be replaced.

100cc bucket was a drama. YZ100 piston circa 1978 were kinda ok. . . Ish.
But only available NOS from random Ebay suppliers in 1 qty.

I grew sick of the increasing risk and went to Kart piston. Of course that means destroking the crank and a oversquare engine.
Convenience trumped design. It had to.