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Case air leak
Posted: 08:49 pm Oct 20 2025
by SpruceItUp
Well! I've got a weird one. I noticed an air leak last week and finally had time to inspect. I was expecting it to be the crank seal- but I think this could be considered worse. It's in the casting about a half inch away from the left crank seal. Just a small pinhole it seems. On the top left corner of that dark rectangle that is circled. I'll post a photo down below. Also- ignore the metal shavings, I had to extract one of the stator screws. My impact screwdriver got the other two, but that final one was a real pain!! haha
Is this a weldable thing? It would be especially great if I could get away with not tearing the engine down to repair, but if need be I will. As much as I hate the stuff for the majority of things engine related, would JB weld fix this so long as I prepare the surface well?
If not- new cases? I know you have to buy them in sets, or at least you should, so I suppose that is an option as well.
One more thing- what would cause this? I know the previous owner ran the thing for a long time without a proper stator cover gasket, which is why there is a bit if dirt in there, which is my bad for not cleaning until now, but it ran great so I just didn't, y'know? I just put a gasket on it and threw it together. It's odd that it was fine until last week.
Thanks guys.
Re: Case air leak
Posted: 11:08 pm Oct 20 2025
by KDXGarage
SpruceItUp, thank you for your post. The 1989 - 1994 KDX200 and some of the early KX60 models sometimes have an issue in that area. The steel insert for the main bearings is on the other side. There is a touch of porosity in that area causing the issue you discovered VERY ACCURATELY. Your thought of thoroughly cleaning the area, sanding / roughening it, then cleaning and using J-B Weld is actually the recommended method. Eric Gorr explained this in his books from 1996/2000/2004. I can not remember if it was in the Kawasaki dealership newsletters or not. I think Fredette mentioned it somewhere.
It is a semi-common issue that pops up from time to time. You might want to look around through the search bar for old posts on it. I have a '94 and did it to mine. I am thinking just filling the little indention to the top should suffice. I can't remember how much room there is between the back of the stator plate, but can't imagine puddling it up high would be good.
Re: Case air leak
Posted: 08:27 am Oct 21 2025
by Chuck78
100%, this is a known issue, and it's always recommended even without detecting any leaks, to clean up scuff up and epoxy fill those areas. The crank cases are the exact same part number for the 95-06 kdx, although they may have potentially corrected the issue and not change the part number. Same with the KDX 220, same cases but different part number due to slightly different machining for deck height tuning alterations for the torque-focused 220.
Re: Case air leak
Posted: 08:57 am Oct 21 2025
by SpruceItUp
Thanks for the responses, guys! I really appreciate it.
So I should fill all three indentations around the crank, then?
That makes me happy, a repair that isn't going to be a pain for once!! Well, other than the screw extraction.. but y'know..
I'll go look for some old posts, I should be able to find some.
I didn't realize the H series and 220 have the same cases.. interesting! Good to know.
Again, thanks!!
Re: Case air leak
Posted: 03:56 pm Oct 21 2025
by Chuck78
SpruceItUp wrote: 08:57 am Oct 21 2025
Thanks for the responses, guys! I really appreciate it.
So I should fill all three indentations around the crank, then?
That makes me happy, a repair that isn't going to be a pain for once!! Well, other than the screw extraction.. but y'know..
I'll go look for some old posts, I should be able to find some.
I didn't realize the H series and 220 have the same cases.. interesting! Good to know.
Again, thanks!!
Yes, degrease & sand down all three of the recessed slots circling the main bearing area, degrease again, & fill with JB Weld or other heavy duty epoxy.
The crankcase halves are the same part number 1989- 2006 on the 200E and 200H, & the 220R (220A) cases, although carrying a different part number, are also made from the same castings, just machine with a slightly different deck height.
The clutchcase housing and the majority of the components in the right side of the bottom end external to the crankcase halves are completely different beyond the gasket, between the 89-94 200E vs 95-06 200H & 220, however. The 220 clutchcase housing is also a different part number vs the 200H, for the same reason as the crankcase halves, slightly different deck height only affecting the power valve actuator linkage retaining pin location, which is very slightly different between the two.
Of course the top ends and power valves are entirely different beyond the piston from 200E versus 200H (piston is 1986-2006, though!), & again on the 220 vs 200H, there are some subtle differences in the power valve components beyond the main power valve exhaust flapper regarding the height of the subport drum bushings etc, and of course the 220 is going to have a larger cylinder bore, different porting, and a head machined for the larger piston size vs the otherwise identical 200H top end.
Re: Case air leak
Posted: 05:01 pm Oct 21 2025
by KDXGarage
According to Partzilla, crankcase halves part number for KDX200 are as follows:
1983 - 1985 : 14001-5157
1986 - 1987 : 14001-5209
1988 : 14001-5241
1989 : 14001-5262
1990 - 1991 : 14001-5276
1992 - 1995 : 14001-5331
1996 - 2006 : 14001-1212
No clue what is different or why, but... there they are.
Re: Case air leak
Posted: 07:36 pm Oct 21 2025
by brademan76
good info I've got a 93 so I'll check and or fill these areas.
If a small pinhole leak is detected, would anyone advise drilling out (not all the way through) with a <1/8 bit before filling?