Author Topic: 86 bottom end with 88 top end  (Read 5799 times)

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Offline jyeomans

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86 bottom end with 88 top end
« on: April 08, 2012, 03:03:48 AM »
Hi all,
I have a complete transmission off an 86 kx 500, and the complete top end off of an 88. Can I match the two together ?

Offline kwakman

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Re: 86 bottom end with 88 top end
« Reply #1 on: April 08, 2012, 06:09:00 AM »
Yep.
And lo, I did loft the front wheel and carried it forth to the unbelievers, and cast it down before them and said unto them ''look now upon the might of my throttle control ye pitiful cretinous ones''
And the unbelievers did quake in their boots....

Offline jyeomans

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Re: 86 bottom end with 88 top end
« Reply #2 on: April 08, 2012, 06:12:44 AM »
thanks

Offline Marco810

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Re: 86 bottom end with 88 top end
« Reply #3 on: April 08, 2012, 06:58:18 AM »
how about a 86 to 88 on a 89+ bottom end?

Offline sandblaster

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Re: 86 bottom end with 88 top end
« Reply #4 on: April 08, 2012, 07:03:13 AM »
Hmmmm, the 86-88 had 2 valves, the 89 and up had 3.
Something would have to give...
I know there are some here that have detailed files on the subject...
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline kwakman

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Re: 86 bottom end with 88 top end
« Reply #5 on: April 08, 2012, 08:34:07 PM »
somebody said it can be done, some say there isnt enough metal to drill the 3rd p/valve hole in the cyl/case face. best bet is to compare the 88 case with an 89 base gasket and have a gander yourself......K.
And lo, I did loft the front wheel and carried it forth to the unbelievers, and cast it down before them and said unto them ''look now upon the might of my throttle control ye pitiful cretinous ones''
And the unbelievers did quake in their boots....

Offline turdle

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Re: 86 bottom end with 88 top end
« Reply #6 on: April 09, 2012, 01:09:28 AM »
how about a 86 to 88 on a 89+ bottom end?
my guess would be you would have to seal the hole for the center kips somehow. not sure tho i dont have a 89 up lower end to look at. :|

Offline jyeomans

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Re: 86 bottom end with 88 top end
« Reply #7 on: April 10, 2012, 11:57:49 AM »
Could I expect any differences in compression ratios. I am assuming 86 and 88 had different head gasket thicknesses?
I am planning on using a 1988 wiseco piston at stock bore.

Offline dave916

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Re: 86 bottom end with 88 top end
« Reply #8 on: April 10, 2012, 10:32:03 PM »
the heads 86 to 88 are all different, the 88 has 0.2mm oem head gasket , 

Offline kwakman

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Re: 86 bottom end with 88 top end
« Reply #9 on: April 11, 2012, 03:48:57 AM »
hold up. you said 86 to 88 on 89 on bottom end? No problem whatsoever. sorry, I read that wrong.if you mean old bottom end to new cylinder you need to check your 86-88 cases against an 89 on gasket before you decide. don46 has the facts on this I believe he runs one on one of his engines, or has at some point....K.
And lo, I did loft the front wheel and carried it forth to the unbelievers, and cast it down before them and said unto them ''look now upon the might of my throttle control ye pitiful cretinous ones''
And the unbelievers did quake in their boots....

Offline don46

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Re: 86 bottom end with 88 top end
« Reply #10 on: April 11, 2012, 04:29:27 AM »
hold up. you said 86 to 88 on 89 on bottom end? No problem whatsoever. sorry, I read that wrong.if you mean old bottom end to new cylinder you need to check your 86-88 cases against an 89 on gasket before you decide. don46 has the facts on this I believe he runs one on one of his engines, or has at some point....K.

Kwakman,

You are right you can go older top on a newer bottom no problem, to go the other way, would take alot of work and you'd have to be a heck of a welder and machinist. There are a few minor differences with the power valve governor, nothing earthshaking. the arm and drum are different, the pin in the arm is bigger, which come to think of it may be better.
Live today, for tomorrow may never come

Offline jyeomans

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Re: 86 bottom end with 88 top end
« Reply #11 on: April 12, 2012, 06:42:13 AM »
 Thanks , about the gaskets!

No, I just meant a 1988 top end mounted on a 1986 bottom end.
I was pretty sure that it was straight forward but I needed check to be sure.
I picked up my top end today from the post office, opened the package to find out someone stripped the power valves out of the cylinder when I paid for the valves to come with it.
Kinda bummed. But I called and they are gonna send me a carb for free.
I now have to track a set down, which from what I understand are hard to find.
Anybody have any suggestions on the best place to find a set?

Offline kwakman

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Re: 86 bottom end with 88 top end
« Reply #12 on: April 13, 2012, 01:34:12 AM »
your 88 cyl will go on 86 cases, they are same generation. Ask Sandblaster about power valves....
And lo, I did loft the front wheel and carried it forth to the unbelievers, and cast it down before them and said unto them ''look now upon the might of my throttle control ye pitiful cretinous ones''
And the unbelievers did quake in their boots....

Offline dave916

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Re: 86 bottom end with 88 top end
« Reply #13 on: April 13, 2012, 03:18:12 AM »
Thanks , about the gaskets!

No, I just meant a 1988 top end mounted on a 1986 bottom end.
I was pretty sure that it was straight forward but I needed check to be sure.
I picked up my top end today from the post office, opened the package to find out someone stripped the power valves out of the cylinder when I paid for the valves to come with it.
Kinda bummed. But I called and they are gonna send me a carb for free.
I now have to track a set down, which from what I understand are hard to find.
Anybody have any suggestions on the best place to find a set?
A carb  is not worth as much as powervalves
 A 88 top end is worthless without good powervalves, seeing that they are not made anymore,
 how much did u pay for the 88 top end? and what did it included {i asume it came with the head as the 88head is completly differant to the 86

A 89on top end will fit 86/88 cases it just a matter of drilling a hole for the 3rd kipps idler gear

also make sure your 86 bottom ends is in good condtion , make sure there is no side play on the crankshaft, i usual try  sideplay with a large flat between crank webs and cases
good luck
 



 

Offline jyeomans

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Re: 86 bottom end with 88 top end
« Reply #14 on: April 13, 2012, 07:41:39 AM »

Well I was bummed about getting the valves stripped,but they were gone and the free carb made things a little better even though I know its not worth as much.
I paid $95 for the cylinder the head and it was supposed to have the valves. Not a bad deal I thought because parts are hard to find in my part of Canada. The whole package was in pretty good shape really.
Im very familiar with the L series kx 250's but this will be my first kx 500 build.