some bottom end questions

[tschisi]

Hi!

I just started to dismantle my bottom end to replace the main bearings and seals.
As suspected, the first questions are raised before the engine is even split. 
I would be glad if you could guide me a little bit through the process, this is my first bottom end.

- Would you replace parts routinely or just the main bearings and seals?
What about the other bearings? Output shaft? I think i have read that standard bearings fit?

- How much clearance is ok for the gearwheels?
Can the ones without pitting stay?

- My clutch basket has rough notches from the clutch discs, i think they are too deep for filing?
http://img7.imageshack.us/i/bottomend007.jpg/
I also have notches on the hub, but this ones can hardly be felt with the fingernail.
http://img97.imageshack.us/i/bottomend001.jpg/

- What about putting thread inserts to the cases, such as helicoil or timesert?
I don?t want to re-assamble everything an then veer a screw.
Do you think there is enough material for drilling and for the inserts?

thx guys!

[jonny500]

if you split the cases you should do all you can. my personal opinion is replace all seals and bearings and every thing that is out of spec. there is a good thread on here where we helped some one else out i will see if i can find it

[jonny500]

ok i found it. http://www.kxriders.com/forums/index.php/topic,7974.msg61265.html#msg61265
its for a 250 but most info is usfull or all. read it from start to finish and you should get a good idea of what you need to do. then of course ask all the question you need to

[tschisi]

nice link, thanks!
Although it has made me afraid of a worn crankshaft... 

What do you think about my clutch basket?
This could become my biggest problem.

[jonny500]

i am not a fan of filing baskets, if you must you have to take the same amount of each finger or there will be uneven stress on the plates. i have known plates to break for this reason. you could spend thousands on it if you want it depends on you budget. if the clutch was working fine then leave it until it starts to misbehave as its an easy job with the motor in the bike.

[tschisi]

Well, without having an eye on this when riding, i didn't notice anything. You're right, i'll focus on that later...

[tschisi]

I removed everything outside of the case, except of the "starwheel".
Does it have to be removed before splitting?
I heard a tool for holding it, and protecting the shift forks, is necessary to open the screw?

edit:
It?s about this wheel:
http://img822.imageshack.us/i/bottomend.jpg/

[tschisi]

Can you please tell me how to deal with this wheel?
I just watched a movie from RockyMountain ATV.MC, and they just opened the screw and took it off.
What if it sits very tight?

[jonny500]

if you mean the part that sits on the end of the sellector drum, then just leave it you can do all you need to do with it in place. post a pic of it if your are unsure

[tschisi]

Pic 2 posts above

[jonny500]

your pics show the clutch basket and inner clutch hub, is that what you mean by the star wheel (i  have never heard of a star wheel)

[tschisi]

No i mean this wheel:
http://img822.imageshack.us/i/bottomend.jpg/

[jonny500]

yep, leave it where it is, you can work around and the cases will split fine with it in place

[tschisi]

It?s split.

I noticed you would routinely replace the 6 inner bearings, 2 main seals and the 3 shift forks.
Right?

Additional i saw two things:

I?ve got pitting on one of my gearwheels.
Is it enough to replace this one?


My crankshaft seems to be worn.
The shiny smooth spot next to the rough areas, from the seal?!
Also the diameters are different.


What do you think?

[allan1353]

IMO on the gear i would find a replacement. As for the crank I'm not sure on sorry