Author Topic: HELP KX 85 Gear Box & Power Valve Problems  (Read 6827 times)

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Offline JOHNTHEGOONER

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HELP KX 85 Gear Box & Power Valve Problems
« on: April 19, 2014, 07:51:47 PM »
Had a problem yesterday with our KX85 it kept jumping into neatrual when under power
Stripped down the clutch side and found a two ball bearings in the casing. After some investigation noticed three ball bearings were missing from the power valve advancer assembly.
Going  to strip the engine to see if then third ball bearing has worked its way into the gearbox.
Can they be put back in and operate OK.

I understand the operation as the that centrifugal force pushes the ball bearings outwards to compress the spring tom turn the power valve shaft. IS THIS CORRECT ????

Could anyone comment on the problem of jumping into neatrual. PLEASE

Thanks
John  :?

Offline Foxx4Beaver

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Re: HELP KX 85 Gear Box & Power Valve Problems
« Reply #1 on: April 19, 2014, 09:53:42 PM »
Can they be put back in and operate OK.

I understand the operation as the that centrifugal force pushes the ball bearings outwards to compress the spring tom turn the power valve shaft. IS THIS CORRECT ????

Could anyone comment on the problem of jumping into neatrual. PLEASE

Thanks
John  :?

1st you need to find out why the balls came out to begin with :?...I've never heard or seen them come out on their own.
Check out this thread starting at the mid-way point of page 2, dirk_411 has explained how they work and is in the process of testing different balls, springs...ect.

http://www.kxriders.com/forums/index.php/topic,12446.15.html

As for jumping out of gear, there could be a few reasons for it....could be as simple as a broken $3 snap ring, or it could be rounded out gear dogs, to a bent shift fork.
My 500 was doing the same thing last year, jumping out of 3rd-4th-5th under power...but mine was a number of things combined, worn shift forks, rounded out gear dogs, worn main shaft.
So for me, it just made sense to replace the entire tranny and gear shift mechanism...it wasn't cheap, but I really didn't want to install some new parts to old parts...all said and done with my discount was just shy of $1500 for the tranny and gear shift mechanism...I doubt it would be that much for an 85, but it'll still be pricey.
Hopefully you won't have to go down that road. You won't know until you get in there...just inspect everything, and replace anything that looks questionable.
Do yourself a favor and spend the $35-ish on all new snap rings regardless too!
« Last Edit: April 20, 2014, 01:05:25 AM by Foxx4Beaver »
Excuse me, ma'am...but you've got extremely nice legs!!!...what time do they open???                                                                                                               https://www.youtube.com/watch?v=n8tCgN3aryQ

Offline sandblaster

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Re: HELP KX 85 Gear Box & Power Valve Problems
« Reply #2 on: April 20, 2014, 04:30:07 AM »
+1

Bad snap rings.... Bad!

The four stroke engine: That's one stroke for producing power and three for wearing the engine out.