Z1OwnersClub GB

Have 2 bikes with issues ( KZ900 and Z1A ) both bought and serviced just prior to my purchase from Cornish Tony suffering from Clutch slippage . I think this is too much of a coincidence and the wrong ( synthetic ) oil has been used.

Neither of the bikes suffered this when first ridden but it has gradualy got worse after a few miles. It started on hard acceleration and within a few miles slips now all the time !

My question is , assuming I am correct, do i just replace oil and filters or would this have caused permanent damage . I don't want to waste my time changing the oils if it won't cure the problem.

Also , assuming worst case of 2 new clutches , is this an easy job as never attempted before and where /What are the best parts .

Any help / comments would nbe much appreciated as want to get both back on the road now the warmer weather coming !

Cheers

Vince

Fully synthetics (unless specifically designed for wetplate bike use) have friction reducers added that will impregnate your friction plates and cause slippage. You could try draining the oil, pulling the clutch plates out and giving them all a good clean with meths or carb cleaner. Stick them back in and bung some good old 10/40 Castrol GTX in the engine. With a bit of luck the residual synthetic oil stuck to the insides of the engine will be so reduced by the fresh oil that it will have no continuing slippage. Might be several oil changes to properly flush it out. This thin, modern stuff, with all its molys, teflon and reducers just wasn't intended for our old lumps.

I've tried super expensive mobil 1 in my ancient Porsche 944 and found it doesn't last long either - consumption rocketed - compared to the Castrol GTX which was top dog when our engines were designed.

Clutch plate replacement is a doddle. Stick the bike in first gear, pull the clutch cover (oil drained, obviously), undo the six (I think) M6 clutch outer pressure plate retaining screws (evenly - using a brace and socket it best - they are preloaded by springs). Carefully remove springs. Remove plates. They will be in an alternating sandwich of friction and pressure plates. Any blued pressure plates ought to be replaced (but I've re-used them before without problems). Reverse the process using new friction plates. Torque M6 screws evenly. Put on new clutch cover gasket. Fit clutch cover. Bike out of gear. Job done.

I find Wemoto are well priced, quick and you can even pay with Paypal.

A kit of friction plates work out at between £41 - £54 ex vat. They also have the clutch cover gasket.

http://shop.wemoto.com/index.dyn?oid=1914605

hello zince, i assume you mean Tony in lostwithiel, where i bought my z1a from. if so, why not contact him and find out what oil was used, he seemed like a nice guy to me, im sure he would be happy to help.
ive had no problems with my bike but i know he had a couple of people work on them.
my thoughts on your oil problem are 1= you have to use a motorcycle engine oil, as they have to work the gearbox as well. 2=could you not give it a couple of goes with engine flush, then put new oil in?
sorry if you already no this.

Thanks very much for the responses , I will try dark skies suggestion and fill up with GTX as I have on my Z1 with no issues , I will also try Mick Z1A's suggestion with the flushing .

MickZ1A , as you suggest Tony was a really nice guy and i have no complaints as am very pleased with the purchase, they are 2 great bikes ! . Think you may be right and Tony should be the first point of call , although it seems likely that this is what hapened as they both were ok for a while but now have the same problem, I also think there were other posts here earlier with issues on his " mechanic ".

Thanks Dark Skies you make the clutch change sound so simple !

Any more ideas welcome and I just look forward to riding very soon !

Cheers