KX Riders
Maintenance & Technical => KX250 / KX125 => Topic started by: dinkyguitar on May 05, 2014, 06:44:05 AM
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Hi All,
I need to replace my crankshaft on my 87 KX 250.
What other bearings should I replace, other than the crankshaft bearings & seals, while I have the case split.
I checked all the bearings and they look good...even the ones on the outside (governor & water pump bearing)
(http://i166.photobucket.com/albums/u84/kezard/20140505_094511_zpse5a39931.jpg)
What about those bushings that hold the needle bearings on the transmission shafts? Should those be replaced if I'm using another used transmission? BTW, one of the bears came off with the crank when I split the case. That's why it's missing from the crankcase.
(http://i166.photobucket.com/albums/u84/kezard/20140505_094312_zpsee8a5b63.jpg)
(http://i166.photobucket.com/albums/u84/kezard/20140505_094445_zps70b61b31.jpg)
(http://i166.photobucket.com/albums/u84/kezard/20140505_094347_zpsd8a61318.jpg)
dinky,
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if you're gonna do it...do it right, do it one time.
replace every bearing and every seal...replace every snap ring...don't half-a$$ it...there's nothing worse than rebuilding a bottom end/engine, just to have it fail shortly after because you skimped out on something, then have to tear it all back down and start from scratch.
don't assume a bearing is good just by "look"....that's where you'll get bitten!...plus, it's best to keep everything uniformly new!
you can save a small fortune by going to your local bearing shop for all your bearings.
check all the gears/forks/shafts/drum, replace anything that looks questionable...I know there's more, but I'm 9 beers deep right now and still dumpin em down....so I'm sure some of the other guys can add to the list.
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+1 8-)
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Absolutely replace all bearings and seals while you have it apart and have peace of mind
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Get crazy with clean up while your at it...
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And... Lap all the mating surfaces...
(http://www.oem-cycle.com/forum/download/file.php?id=709)
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Yep...that's the way I'm leaning right now...replacing everything I can so I don't have to split the cases.
So, I got this bike for free. The clutch looks new, the cylinder still has the cross hatching, and the piston also looks good. Keep in mind this bike sat for 8 years in a shed, so I'm planning on looking at everything.
I have the service manual and already started measuring the clutch disk and metal plates. The clutch looks new and they all measure within the "new" specifications.
This bike could be a good project to restore since it's a 1987 model.
The way I look at it, if I spend even up to $1500.00, I will literally have a new bike. If I bought a 250 for $1500.00, (if there are any for that price) I would still not know what condition it was in, and will probably have to replace a part or two in the future.
By ripping the bike completely apart like I'm doing, at least I know what it looks like inside.
dinky,
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Are there bearing pullers for these smallish bearings circled in this photo? I have some in my 89 KX125 that also need replacing.
(http://i.imgur.com/xogUnsR.jpg)
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Are there bearing pullers for these smallish bearings circled in this photo? I have some in my 89 KX125 that also need replacing.
I was curious how I was going to remove these too... :?
dinky,
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You need a blind bearing puller.
Here's some pics and how they work:
http://www.oem-cycle.com/forum/viewtopic.php?f=39&t=64 (http://www.oem-cycle.com/forum/viewtopic.php?f=39&t=64)
I bet you can rent one from your local auto parts house.
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Cool tool, but probably expensive....
Now that I've seen that, I could probably fabricate something out of an anchor bolt from home depot.
dinky,
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They have 5-piece blind pullers on ebay for $50 free shipping but I'm wondering if the MP one has smaller collets for our KX engines............
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My cheap eBay set wouldn't get the power valve bearing or the clutch lever bearings.
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The only one on the K5 that I can't get with the MP is the lower clutch arm bearing as it isn't long enough.
But you can make a extension for it like alward25 did
(http://www.oem-cycle.com/forum/download/file.php?id=1145)
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My puller Is for rent for the price of shipping, just need to know which bearings you want to pull so I can be sure to have the right size puller.
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My puller Is for rent for the price of shipping, just need to know which bearings you want to pull so I can be sure to have the right size puller.
Saved me a from buying a new set.
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You can make your own puller using concrete anchor bolts and slide hammer .
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My puller Is for rent for the price of shipping, just need to know which bearings you want to pull so I can be sure to have the right size puller.
PM sent.