Kawasaki KL600 waterpump impeller shaft problem

[J.B. Welding]

Ok, so I've had one of those calls-a good customer with a wee problem outwith my field, was wondering if anyone had any ideas. The seal on the above shaft has been replaced but is still losing water to the oil, and I think oil to the water too. The guy tells me there is a tiny groove worn in the shaft where the seal sits, and this is the problem. My only thought to cure this is to tig-fill the groove and lathe it back to round again, pretty labour intensive and fiddly, as the shaft will be quite small, there will probably be be a bit of distortion and it could be a pig to get in my big lathe. He can only find a second hand shaft in America. Any ideas or suggestions welcome and appreciated!

 

[711jrp]

Could you put a washer in before the seal that way the lip will run on a virgin portion of the shaft?

 

[J.B. Welding]

I'll suggest that, good thinkin!

 

[Rig Pig]

You may be able to fit a shaft repair sleeve, they just slip on quick and easy!

 

[bs2236]

Speedy Sleeve would be the easiest way

http://simplybearings.co.uk/shop/index.php?cPath=4713_4847

Used them loads of times with generally good results

 

[J.B. Welding]

Do you just bond them onto the shaft with some loctite?
Think I used one of these as an apprentice on a tractor somewhere...a big one!

 

[brightspark]

Do you just bond them onto the shaft with some loctite?
Think I used one of these as an apprentice on a tractor somewhere...a big one!

what happens about needing the increased size oilseal and do u have to get a new oversize bearing to suit??

 

[500e]

Timkin & Parker also do sleeves but I think 11.8mm 0r thereabout is smallest, with some sleeves you can use standard seal it is so thin.
Only ever used Imperial 7 over 1inch.

 

[AndyStobbs]

Think the idea is simply to move the seal axially with the washer behind it. Space permitting.

 

[BrokenBiker]

is it not possible to machine a new shaft?

 

[Rig Pig]

The sleeve is so thin you can use a standard seal, a drop of locktite and your ready to put it back together. It saves hours of machine work!

 

[brightspark]

The sleeve is so thin you can use a standard seal, a drop of locktite and your ready to put it back together. It saves hours of machine work!

but what about the bearing aeria ??as that would be worn also

 

[Rig Pig]

The sleeves are only there for the seal to run on, if the bearing face is knackerd then it's going to be even more fun, hard chrome or metal spray and a spin on a cylindrical grinder.

 

[Rig Pig]

Out of interest what size is the shaft?

 

[J.B. Welding]

I've not seen the shaft but I recon it will be around the half inch mark, bearing is apparently good and my mates mate, who is a bike mechanic, was flummoxed by the recurring seal problem, hence the call to me. If there is room I recon the washer system is the one, failing that one of those speedi seals will fix it,although they do seem a bit pricey for what they are- a helicoil in the shaft repair world!

 

[wyn]

From what i remember of days spent messing around with japanese mx engines...they had two seals .

One kept the water in the other kept the oil in...there was a gap between that had a drilling through the case to the outside. Any water leak would come out of this hole.

Are they certain this is where the oil/water is getting mixed?

 

[Hudmut]

Iv done this sort of repair many times but mainly on wet diamond core drills bat have done this a few bike pumps. I turn the shaft down press a stainless sleeve on made from 303 and then with a tool post grinder bring the shaft back to size and its no fancy tool post grinder just a Dremel G clamped to the tool post of the lathe

 

[J.B. Welding]

Well thanks all for the input, really good stuff. I had another chat with me mate and he mentioned he had already tried a nylon washer in the back of the seal to move it across but still same problem occuring. This is all after they have had the head off and inspected it, including feeling around in the barrel for cracks, new gaskets etc. Wyn yes you are right the no mans land inbetween the seals should really stop any fluid transfer, but he tells me the new oil seal is a wee bit slack on the shaft and wants to try a speedy sleeve () to eliminate that part of the system. Seems to be a lot of water he's talking about a litre of water in oil after 5 miles riding, I fear that he may be clutching at straws with small seals problems after our talk. Hope he doesn't call me up asking if I can weld up low half hairline cracks in piston barrels.....if the head is good what else could it be? Bloomin old bikes-got to get my Cagiva back on the field before I start actually looking at other folks' ones!

 

[Rig Pig]

Is the head back on? If not get it vacuum tested an an engine reconditioning workshop, it may have an internal crack. Have the head and block been checked to see how flat they are? And is it a wet liner engine - May be a liner seal has failed, or corrosion around the bottom of the liner if the coolant has been neglected.

You could try pressurising the water jacket with a compressor, and listening in the ports and orifices of the engine for hissing, it may help, don't go crazy on the pressure 20 - 30 PSI or whatever the radiator cap is rated to as a max.