A few questions about the bottom end

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dgraver1
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A few questions about the bottom end

Post by dgraver1 »

Hi, so I havent been around for a long time, but basically a top end job went bad when a wristping circlip fell into the cylinder. I have since taken the engine out of my 03 kdx 200, taken the top end off, and split the cases searching for the pieces.. couldnt find any peices anywhere. I have a few questions before I start reassembly of the bottom end though.

I ran into an issue when I pulled the left side of the bottom end. For some reason the crank shaft bearing stayed on the crank. I had a hell of a time getting it off, but I did not know if this was a common occurance. I read another post where it said to use a bearing retaining compound made by loctite. any experiences? Is this a bad sign?

Also, Is there any must replace items that I would be crazy to not replace since Im already in there? ie. bearings or seals?

Any assistance is appreciated! Thanks!!
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Re: A few questions about the bottom end

Post by SS109 »

Bearing staying on the crank is very common and a non-issue other than getting them off! You don't need any type of Loctite on your crank bearings. Trust me, they fit plenty tight as you have already found out. Personally, if I'm splitting the cases I'm replacing every bearing, race, and bushing inside the bottom end while it is apart unless the bike is low hours. Absolutely, at minimum, replace your crank bearings and crank seals.
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kawagumby
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Re: A few questions about the bottom end

Post by kawagumby »

Being a cheap skate I don't replace all the bearings but even I replace the countershaft bearing along with the crank bearings. That bearing takes a lot of hits from the chain - torque,rocks/sus.bottoming etc... and is only about $15.
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dgraver1
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A few questions about the bottom end

Post by dgraver1 »

So I want to ask if i should get the crank rebuilt.

My engine ate one of the piston circlips and I have the bottom end apart. I sprayed everything out, but I just want to be 110% sure that everything is perfect so I dont F* up another cylinder/piston/head.

Also If i do get it rebuilt where should I send it to have it done?
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Re: A few questions about the bottom end

Post by Julien D »

When the crank is rebuilt, The crank pin, rod, and lower end bearing are replaced. Is the rod damaged, or is there up and down play in the lower end bearing? A rod kit will run about $80. An hour labor to rebuild it, plus shipping if you don't have a local place that can do the work. I can't tell if it needs rebuilt from here, but if the rod can be moved up and down, or the bearing feels "notchy" at all, it would need to be rebuilt.
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dgraver1
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A few questions about the bottom end

Post by dgraver1 »

No up and down play. I think I am just being overly cautious with the rebuild because of what happened the first time I did the top end. I figure if it's not way to rediculously priced I would have it done.. If it is somewhat consumable like a top end.

On a positive note, I just received a beautiful top end back from langcourt. (second time around!)

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dgraver1
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A few questions about the bottom end

Post by dgraver1 »

So next up is replace the bottom end main bearings and seals.
After that I have to service my rear shock. It isn't holding oil after i rebuilt it.(of course). It seemed fairly easy to rebuild, I'm thinking I just didn't have something seated correctly, maybe too much oil?

Question is, should I rebuild it myself or just send it to race tech or somewhere along those lines.

Thirdly, I want to service my front forks. I swapped the front end for kx forks, and the 5 or so rides I got with new top end/rb carb & head and front forks was incredible.. Like a totally different bike! Just for good memories here is a pic right after I rebuilt everything..

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Julien D
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Re: A few questions about the bottom end

Post by Julien D »

The lower rod bearing and pin are indeed "somewhat consumable". If you really want to replace everything that you can or should while you're in there, it's definitely not a bad idea. If everything is within spec it's not necessary.

Fork service is not too complicated. I would go ahead and tackle that one yourself. The knowledge you gain servicing them will be valuable. I've actually never done a shock myself. I just send them off. Several folks here have, and do. I'm sure someone here can answer any specific questions on the shock.
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A few questions about the bottom end

Post by Dekon »

I was thinking about doing my shock and saved this link: http://onlytrailbikes.com/2011/03/23/ho ... ear-shock/

Maybe you just missed a step some where and that is why you are still losing fuild. Just an idea.
dgraver1
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A few questions about the bottom end

Post by dgraver1 »

Thanks for the link. And I don't think I'm gonna replace it.. No need to spend money when it doesn't really have to be done.
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