'99 KX 250 crank seal install direction

[freds40]

I've been into this motor once and changed the seals. Since my FSM didn't show directionality of the seals, I just put the new ones in like the old ones came out which had the flat side of the seals facing the clutch and flywheel and the spring facing the crank on both sides.

The motor is smoking and using trans oil and I have a KDX trans to throw in so I've got it torn back down. As I think about this, I believe the right side should have had the flat side facing the crank and the spring facing the clutch but I think the left side was correct.

Just looking for clarification.

[no1clyde]

You have them correct, the open spring side goes to the crank and the flat side go to the out side. When you put the crank into the right side case it is VERY easy to roll the lip of the seal so be extra careful.

You are the first person I have heard that is going to put the KDX transmission in, let me know how it goes for you and if I can help just ask.

Ed

[freds40]

Thanks Ed.

I spoke with you a couple of months back about the trans. I found a '92 KDX250 right case half, crank, clutch basket, and trans for $100. I figure I might be able to make a few bucks back on the other parts when I'm done. I've got the bushings and sleeve all ready to go, hopefully be able to ride it next week.

[Jeekinz]

As I think about this, I believe the right side should have had the flat side facing the crank and the spring facing the clutch

That would be a proper installation if there was no pressure on the other (crankcase) side.

Like Ed said, you might have rolled the seal lip. Make sure you lube the crank ends and seal surfaces to help with assembly. You can use premix oil, light coat of grease, etc.

[freds40]

Yeah I had used grease last time but I'll make sure to take my time and pay close attention this go around. Thanks.

[no1clyde]

Thanks Ed.

I spoke with you a couple of months back about the trans. I found a '92 KDX250 right case half, crank, clutch basket, and trans for $100. I figure I might be able to make a few bucks back on the other parts when I'm done. I've got the bushings and sleeve all ready to go, hopefully be able to ride it next week.

I remember talking with you,all our old PMs are gone now. I hope you got the KDX shift forks too. If you could get the rest of the parts from it you could also put the KDX ignition on and get lights too if that is something you would want. If your 99 has the stock transmission you will be amazed with the new setup.

Good luck and hopefully next week we will get a ride report ?

Ed

[Honduhminiman]

what benefit does the KDX tranny have over the KX?

[HolyKaw810]

what benefit does the KDX tranny have over the KX?

gear ratio

[Honduhminiman]

i figured it had a different ratio but what im asking is how does the ratio help? is it a lower or higher ratio? is it better for tight trails or high speeds?

[no1clyde]

The KDX transmission has a much wider spread than a stock 99, low is much lower and second is about the same as 1'st use to be in the 99 and 5'th is also an overdrive in the KDX. Here is a thread I did on it https://www.thumpertalk.com/topic/902713-91-94-kdx-trans-into-a-01-kx/page__fromsearch__1 . As far as I know I am the only one that has done it so far but there are a few interested in doing it. It makes the KX a great trail bike. Here is another thread on my trail bike https://www.thumpertalk.com/topic/905311-my-trail-bike/page__fromsearch__1 . If you are a trail rider it is a great mod to do.

Ed

[Honduhminiman]

thank you for all of that info, exactly what i was looking for

[freds40]

I keep telling my riding buddies this will give me both a first and second gear. ?