YOSHIMURA 820CC PISTON KIT - YAMAHA XJ750

http://cgi.ebay.co.uk/YOSHIMURA-820CC-P ... 5199aabca8

Found this what I believe to be rare 820cc big bore piston kit for an XJ750. I have seen new old stock gaskets for these kits and rings but never the full kit. The seller has two of theses kits in the UK, I was wondering if these kits come up often in the USA and other countries? All so if this kit was installed just how much extra power you would get with the right setup, I was thinking XJ900 carbs, head and many more modifications you would have to make to get maximum performance from the kit.


Is XJ900 carbs and head possible? What and where would you have to go for the bigger bores/resleve? I think the kit would go well on a streetfighter/racer XJ750, so was just posting to see what you all think and if any of you have used this kit or know any thing about it. I would be tempted to buy a kit but have to find £170 for parts on my Yamaha TZR50.

Thanks AL

 

Oh, golly.

That is a rare find. I can think of a couple of XJ750 owners that may mess themselves when they see that.

You would take the new pistons and your cylinders to a machine shop with the clearance specs and let them work their magic.

 

Thats great, I just wish I had the cash to buy a set.

 

It’s all so amazing he has two of them.

 

Damn, I wish I had a 750. Cool find.

 

love it.
i may have to bid on this. cant find std size rings anywhere but chacals. ..

have to ask how much € for boring my cylinders

 

Great to hear you may be bidding, if you do i would like to seen you do a build thred on what you do with it.

 

someone made an offer for it, who was it?!

problem with the kit is theres no head gasket included..

defo if someday i have sh!t that cool, you will see pics !

 

There are two kits, one with a head gasket and one with out. The one with the gasket is £100 and with out is £80.

 

Is there any possibility/workaround for these to fit and work in XJ650?

 

man that is awesome.

 

Shame we will never get to see it on a bike.

 

You will now.

 

No way?

 

you didnt? ?

 

Shipped yesterday. I have a Wiseco 820 big bore head gasket waiting for it.

Pumba's new engine will be 820cc + EFI with a 900 middle gear set...


So it now seems I have a new set of 2nd oversize factory pistons, rings, pins and clips for spares. And the Wiseco 820 kit that is short some bloody expensive rings.

 

Score !

Loose piston rings are available from a number of suppliers, I used to buy them for our dirt racers from a guy here in Brisbane. You will have to specify everything, ring profile, material, size, gap, end details, etc. We used to just take an old one in and they would match them up.

I have also sourced online custom made rings for old aircraft engines we have rebuilt, sorry I can't remember the name of the company. Try the google for "custom piston rings". You will be surprised how reasonably priced they are and how many suppliers are around.

 

I only need the 4 oil scraper rings that are missing (2 pistons worth), and the only way Wiseco sell then are as a per piston set. Wiseco USA won't sell to Australia. The Australian distributor is Serco, and they wont even do credit card over the phone.

The Wisecos are going into the cupboard for a while, as they are needed for the next engine which will be phase 3 of the Pumba project, that will probably be over 18 months away at my current rate.

 

Can you get one of the dudes on here who lives in the US to source them for you and post them out?

 

Contact Grant Ring Company in SoCal...They can and will make you custom Moly rings for any bore size/type of piston... I had them make me rings for my Porsche 924 Mahle pistons when I couldn't find ANY rings anywhere for my application.

They can whip em right out.
Good Luck
Jay