KZ 305 very smokey exhaust

Hi Guys, I haven't been on for a while. For the most part since I got my KZ cafe on the road she's been running pretty well. I recently had a leaky float bowl so I took the carbs off to clean them & check the float needle etc & the leak has mostly stopped. After I tuned it up I took her for a couple of runs including a speed test where I got her up to about 170kph (105mph) I was pretty stoked we could 'do the ton' just after that the exhaust got really smokey. 'Oh no, I've broken it!' was my first thought and that still might be true. I phoned my mechanic, he suggested that some fuel may have gotten into the oil increasing the viscosity and allowing the oil to get where it shouldn't & causing smoke so he suggested oil & filter change. So we did that yesterday. They seemed to think it was fine but this morning it was smoky as hell again. I'm not sure if it blue or grey smoke, grey I think. Also there seems to be some smoke coming from the crank case breather too. Just on that, when I removed my carbs I also took off the crank case breather & the little hose was full of horrible creamy snot stuff!

The Mech's did a compression test & got 95 &92 I think, not sure what stock is but similar is good, so the ring should be ok. We did the rings during my rebuild, it has 1500 km's on it since then. The PO suggested there might be a problem with the valve seals? would that be the valve guides? In any case they are discontinued.

Any suggestions on the smoky issue?
Thanks
Hama

The published top speed for the KZ305 is 96.7 mph (see specs below). Assuming your bike has stock gearing, if it actually was running at 105 mph the engine would have been far past redline. If that was the case you may have damaged it. However, it is possible that even though the speedometer showed 105 mph the bike was actually traveling much slower; the speedometers on KZ models are not highly accurate devices. What rpm did the tachometer show when you were going 105 mph? Ed

www.motorcyclespecs.co.za/model/kawasaki...aki_z305csr%2081.htm

Well I don't run a tacho so there's a good chance I red lined it. Ooops! What sort of damage might this cause?

Valve guide seals.
Steve

Thanks Steve, she's in the shop now getting the new valve guide seals. I sure hope that does the trick. And I hope they do a decent job on sealing up the rocker cover. Last time it was leaking so the smeared sealant all over the outside of the leaking bolt. I could have done a crap job like that myself!

Sadly valve guide seals have done nothing to fix the smokey exhaust. Now I'm looking at a re-bore / hone & new pistons & rings +0.50 oversize.
www.partzilla.com/parts/detail/kawasaki/KP-13029-1019.html
But of course I can't get em. I've checked Vintagekawasaki.com and searched the net extensively but with no joy.
So do I get custom pistons & rings made? How do I specify those? Any other otions or suggestions?