Kawasaki Ninja ZX Forum banner

1 - 15 of 15 Posts

·
Registered
Joined
·
94 Posts
Discussion Starter · #1 ·
Hi just want to get a concenses on what might be wrong with my 94 ZX-11
I resently had the top end rebuilt by a reputable shop and after a break-in period of 1000 miles I still seem to be loseing oil. It's not leaking but must be burning oil even though I can't see any smoke out the tail pipe. It also seems to foul plugs because after about 500 miles and a adjustment of the valves the plugs also had to be replaced this also was done at the shop as a finsh to the top end rebuild. Now after 1000 miles and a very easy break in to seat the valves I still seem to be loseing oil and fouling plugs and the bike is not run as strong as it should. Now I'm sure that if I replace the plugs again it would run better but thats just the simple fix to a bigger problem I have a feeling. Does anyone have any Ideas on what this might be. The compression on the motor at 500 miles was 175 176 165 170, shop said it was probably still seating in the valves. Does anyone have any advise as to what I might be experincing. Sure would like to know whats going on with her and get it taken care of.:banghead
 

·
Registered
Joined
·
532 Posts
Oil usage together with plugs fouling is usually a sure sign of oil rings not 100 percent if the top is OK. From the compressions you give, the third and fourth is a little lower that the first two, although the fourth one is not too much of a concern.

I will bet that the plug on that cylinder (no.3),will show the most carbon and soot!
Although the compression doesn't seem too bad, the oil rings might be broken or worn and oil will still seep past the compression rings.

I am very surprised that your guy who did the head still try to comfort you by telling you that the valves must still seat properly. Valves seat immediately after machining or grinding of the valve seats. They do not wear themselves "in". Valves that don't seat properly do not use oil, (unless it is the valve-stem seals), but will cause backfiring or "missing" through the exhaust.

Get another opinion from someone else!
 

·
Registered
Joined
·
94 Posts
Discussion Starter · #4 ·
Well here's what happed, I Had a broken ring in the #4 cylinder and the shop is going to replace the pistons with new ones (one over, because it scored the cylinder) and rebuild the top end again at no cost to me, It is presently waiting for machine work then another rebuild. Hope this one turns out better than the first. Wish me luck!
 

·
Registered
Joined
·
2,167 Posts
Unless this changed recently, I think there is no oversize piston available from Kawasaki. What will your dealer use as a piston?
 

·
Registered
Joined
·
94 Posts
Discussion Starter · #6 ·
I was told it was a one over made by J-n-E , the west coast company of Wesco. Forged piston. They were $550, cylinders had to be machined. I was also told that these are very reliable parts and used in many race built engines. Hope it's the truth! Guess I will find out soon enough. Any tips you can share with me would be appreciated.
 

·
Registered
Joined
·
94 Posts
Discussion Starter · #7 ·
I was told it was a one over made by J-n-E , the west coast company of Wesco. Forged piston. They were $550, cylinders had to be machined. I was also told that these are very reliable parts and used in many race built engines. Hope it's the truth! Guess I will find out soon enough. Any tips you can share with me would be appreciated.
 

·
Registered
Joined
·
432 Posts
J&E are well known piston makers, with a good reputation. About 15 years ago I had them make a set of Pistons to fit a special set of chromemoly liners for my late wife's Renault R-5Turbo Tour de Corse. Nice quality, fit perfectly and inexpensive [$250] compared to the $2,000US Renault Sport wanted.

So, I'd not worry. The shop seems to reputable enough. I mean, they accepted responsibility..something which is rare indeed these days.
 

·
Registered
Joined
·
236 Posts
glad you figured out the problem before more damage occurred. It's also rare a shop accepts responsibility, as stated above.. so congrats on that.

Just a note.. I believe that the break in period is only for setting the rings on the pistons properly... it's my understanding that the bearings, valves, springs, etc.. are pretty much broke in immediately.

good luck with your re-repair.. I hope it goes well for you.. and as a plus.. with the bigger pistons.. you'll get a little added torque.. so BONUS!!!

Hurc
 

·
Registered
Joined
·
432 Posts
Hurc is correct..and with the new ring manufacturing process' even ring break-in is all but un-necessary. Just a few runs up and down the rev range..after full warm-up of course..and you're all set to go.
 

·
Registered
Joined
·
94 Posts
Discussion Starter · #11 ·
Thanks for all those tips, and yes the shop is tring to be and do the right thing here, so even though it is taking a while to get the bike right and back I'm still happy.
 

·
Registered
Joined
·
94 Posts
Discussion Starter · #12 ·
Wow, got my bike back and she runs great still a little nervous about winding her up but I have about 300 miles on her and think now I can open her up some. Any Ideas on break in I havent taken her over 6 grand yet, The mecahnic said 100 to 200 miles and then it's ok but I just want to make sure.
Claude any advise?
 

·
Registered
Joined
·
2,167 Posts
I think 300 miles should be OK. Just don't hold it at high RPM for continuous periods. At 6000 RPM, it is only purrrrring...
 
1 - 15 of 15 Posts
Top