Inlet valve size

[corpy]

The 1100 engine in my trike is stamped KZT 10AE00**** which I think is from a 1981 A1 or A2 shaft drive.
I am having difficulty in getting new inlet valves for it. They are 38mm head diam., and about 90.5-90.7 overall length. Stem diam. is nominally 7mm.
The o.d. of the seats (inserts) is about 40mm and the bores of them are about 33.5mm.
Valves with 37mm heads can be got easily enough, but 38mm seems to be unusual.
The barrel doesn't have counterbores for o-rings, so does this point to the engine being a bit special, or very old?
I would appreciate advice, please.

[Al]

A2 engine numbers start at KZT10AE-006701 and run to KZT10AE-015801 lower numbers will be A1 and higher obviously A3.

https://www.z-power.co.uk/merchantmanag ... php?pId=34

From the pictures you posted recently and the descriptions given it appears to be a Unitrack top end grafted onto the shaft drive bottom end.
Youre head looks very much like a unitrack from the pictures of the combustion chamber etc.
It was also mentioned that the Unitrack barrels dont have the spot face for the 'O' rings. So probably neither old or special!!!!!

I think you may be looking for 1100 A1 (2) (3) valves when you should be looking for Unitrack ones perhaps.

Got my last Unitrack valves from Ray Debben but others should have them.

ZPower list the smaller valves for the J, 1100, A, ST etc but i cant see them for the Unitrack. However they do not list all their stuff on the site as i have found out recently.

https://www.z-power.co.uk/merchantmanag ... ts_id=2055

What is the reason for needing new valves?
Is it because you have gone below the minimum thickness for the shims?
If so you may find it cheaper to get the tops of the valve stems 'tipped'

I think you can get up to something like 0.3 mm taken off safely at an engineering shop before you go through the surface hardening or have contact between bucket (shim) and valve retainer caps.
Not a DIY job as it must be maintained square.

AL

[corpy]

Thanks yet again, Zorded.
From what you say about engine numbers the original bike was an A1.
When you advised me in Sept about torques etc you warned me that a valve could be bent through carelessness when fitting the camshafts to the head, on the bench. Well, silly old prat that I am, that is exactly what I did; it happened easily and I didn't know that I had done it until I finally checked all the valve sealings using paraffin.
I hadn't heard of the paraffin test for valve seat sealing until recently when I came across it on YouTube. I don't know how long you are supposed to give it before judging the seal to be ok., but I guess that because it is so 'thin' it will leak through given time.
I am just glad that I did the test then, before re-fitting the head.

[Al]

When you advised me in Sept about torques etc you warned me that a valve could be bent through carelessness when fitting the camshafts to the head, on the bench. Well, silly old prat that I am, that is exactly what I did; it happened easily and I didn't know that I had done it until I finally checked all the valve sealings using paraffin.

Dont beat yourself up, how did i know to warn you about it?????

The paraffin thing may just be a comparitive assessment. I remember doing it years ago on a cylinder head that had good valves and seats and it still came out pretty quick.
If you want to see if the valves are sealing all round get a permanent marker pen and colour in the mating face of the valve head. Lap it with the tool in the normal way with no paste and see what you get. Its the same as engineers blue but for DIY uses.

Measured some Unitrack valves last night and they are 38mm for the inlet valves.
Think this may be them but the number has been superseeded for Unitrack valves to this number 120041087

http://www.cmsnl.com/products/12004-108 ... 120041021/

Heres a link to the parts list for the 1100 A1 in case you need any other part numbers
http://www.cmsnl.com/kawasaki-1981-kz11 ... partslist/

AL