TOPIC:

Ahhh, the topic that never ends....yet???

A number of years back, I bought a spare cylinder block and cylinder head. EBay had a few deals on so I capitalized on them. Last month for shits and giggles ('cause that's what we do here in Canada Eh??) I also bought a set of stock KZ750H pistons which are 66mm bore diameter. I've heard that it's possible to machine the cylinder block and install oversize wet sleeves, so I'm investigating the possibility. this bike is all about the possibility of being something of my creation and it's a long term project to see what I can do with my abilities.

I need to pull the cylinder sleeves to measure up the block and see just what is available in material for boring the crank case for larger sleeves and what material is in the block to machine out the block for the sleeves.
Wet sleeves are typically fitted with .003" interference fit and if I heat up the cylinder to around 300-350 deg. F, the cylinders should just tap out. Before I heat up the cylinder, I needed to remove the water pump drive shafts, the nylon sprocket and the mechanical seal. What a PITA removing that impeller.  Penetrating oil soak for a day, then a couple of pairs of needle nose pliers on the impeller bladess and wiggle. More penetrating oil. Wiggle. Black effluent was coming out from around the shaft and impeller. wipe it off. Soak with penetrating oil. Wiggle, wiggle wiggle. leave it soak for another day, Then the impeller starts to wobble a bit. Hmmmm. Finally, it comes off.
What a friggin mess underneath. See pics.

 
Bottom side of the mechanical seal housing

 
Cylinder head cavity where the seal housing mounts. Note the excess silicone sealant around the edges. Somebody (butcher) did a seal previously. So much crud, you can't see the lip seal under the crud.

 
Back side the the stationary mechanical seal in the impeller. Note the crud buried in the impeller behind the ceramic seal.

 
Water pump drive shaft. Pretty fuggly

 
Before cleaning 

 
After cleaning up the shaft and paying attention to the area that the lip seal rides on with 1500 wet/dry paper and penetrating oil, this is what's left. Measuring the surface at the area I think the lip seal rides on, it measures .003" less than there area that the shaft journal measures. Not good, but maybe f I can find a shallow fitting lip seal, I may be able to get the lip of the seal to ride on a fresh area of the journal and not have to replace the shaft. We'll see.
The other repair option would be to brush plate the damaged area with copper, then machine grind to diameter and then brush plate with chrome. We used to repair shafts in the nuclear plant with this process. Pretty neat and you're left with a chromium surface for the lip seal to ride on.

Youtube, repairing a shaft with brush plating 45 seconds
Caswell brush plating copper video 2:45 minutes
 

You would think finding a mechanical seal would be straight forward. I've used High-Tech seals in Newmarket Ontario many times before. Went to their warehouse today with parts in hand and as of 2019 when Covid hit, they closed up the doors and no longer offer counter assistance. You want help, send in the info and "we'll get back to you". Even when I called them from the parking lot and told them I was there, their only response was " You'll have to go to the manufacturer and get the stock part."
"It's a 43 year old motorcycle and parts are no longer available" I replied
"Try the internet" they said

I went to 5 different outlets including a pool supplier, an electrical motor rebuilder, a hydraulics repair shop, and an auto parts supplier. No luck yet.

I copied a drawing from the CMSNL site and added dimensions for the seal parts.



 

KB, I ordered and received a seal from Germany.. In my little hood could not find a 'spa replacement'.

FWIW, the seal fit into place.

Just today put coolant into system.. but no fire up yet. 

Hopefully all is good.

Good luck.

D

At the time I went to a small family workshop that is dedicated to repairing all types of water pumps, in fact, they are the ones that repair the water pumps of all the agricultural machinery that I own.

When they saw the old seal they immediately identified it by taking measurements with the caliper.

He then brought a large box full of spare parts and loose parts and searching around found what I needed.

They don't have it in stock but they knew there were some lost in the warehouse.

That was my lucky day with this bike.

I can tell you its NOT this.

Measurements of Z1300.de seal and others here. Maybe of some help ?