Two Stroke Motocross

Two Stroke Motocross Forum => Technical => Topic started by: eprovenzano on July 21, 2013, 01:54:55 PM

Title: Hard to find neutral after bottom and top end rebuild
Post by: eprovenzano on July 21, 2013, 01:54:55 PM
This question is on my son's thumper, but this is something that's not 2 or 4 stroke related, it could be on any bike.

I finished rebuilding my son's 06 KTM 250SXF..  when we got the bike the engine was disassembled and in a crate.  We put in a new crank, bearings, piston, rings, etc.  Basically a two stroke bottom and top end rebuild, as the valves were all in spec...  (Thank God)...  The bike runs well, (for a 250F), but I'm having one issue...  It's really difficult to find neutral.  When I do find neutral it seems to be between 2nd and 3rd gear...  but to find 1st gear, it only takes on click down...  My only thought is I have something wrong with the gear selector.

From my manual here us the installation of the gear selector. 



It really only goes together one way, and I believe I put it together correctly, but...  something is not right.  When I had the cases open, I left the tranny in the side case, and never pulled it out.  So I'm leaning towards the gear selector. 

Any thoughts guys.


Title: Hard to find neutral after bottom and top end rebuild
Post by: citabjockey on July 21, 2013, 03:11:58 PM
How does the indexer mate with the drum? Note in the manual it says that the flats are not symmetrical. Seems like it may be possible to install it off by 180 degrees but then it would be offset from the drum axis. Is this possible in your case?
Title: Hard to find neutral after bottom and top end rebuild
Post by: eprovenzano on July 21, 2013, 03:16:51 PM
Good question... but the two sides are a different size, so it really only goes in one way. 

I just dread the thought of having to go back in (again) this will be the third time...  although I can drain all fluids, and have the side cases off in 45 min.  I guess I'm just fishing as to what to look for...
Title: Hard to find neutral after bottom and top end rebuild
Post by: SachsGS on July 21, 2013, 04:35:34 PM
Since the bike was a basket case, did the previous owner have this problem? As well, is the shift drum aluminum?
Title: Hard to find neutral after bottom and top end rebuild
Post by: eprovenzano on July 21, 2013, 05:52:12 PM
Quote from: citabjockey on July 21, 2013, 10:11:58 PM
How does the indexer mate with the drum? Note in the manual it says that the flats are not symmetrical. Seems like it may be possible to install it off by 180 degrees but then it would be offset from the drum axis. Is this possible in your case?

The indexer has two different sizes so it can only do in one way. 

Quote from: SachsGS on July 21, 2013, 11:35:34 PM
Since the bike was a basket case, did the previous owner have this problem? As well, is the shift drum aluminum?

Good question Sachs, I don't know.  I'll contact the PO to see if he had this problem. 

I posted this same question on a few "other" web sites, and can you believe this is the only place where I get a response. Why am I not surprised...  :o
Title: Hard to find neutral after bottom and top end rebuild
Post by: citabjockey on July 21, 2013, 06:50:01 PM
What specifically do you mean by "two different sizes"? If the block portion has parallel sides it "could" go in 180 degrees off -- it would just be offset from center a touch -- and the neutral detent would be 180 degrees away from the follower wheel when the tranny is REALLY in neutral. Can you take the covers off (45 min, right?) and the pull back the follower arm while turning the drum to find the REAL neutral. Then shoot a picture and post here.
Title: Hard to find neutral after bottom and top end rebuild
Post by: VintageBlueSmoke on July 22, 2013, 10:57:07 AM
The extra neutrals were left out and used in old Zundapps and Sachs...

 ;D
Title: Hard to find neutral after bottom and top end rebuild
Post by: SachsGS on July 22, 2013, 03:59:44 PM
Easy there VBS....those old Sachs and Zundapps created the small bore classes. ;)

Title: Hard to find neutral after bottom and top end rebuild
Post by: citabjockey on July 22, 2013, 05:09:32 PM
because the trannys could not handle big pistons?

(ducking now)

 :D

Quote from: SachsGS on July 22, 2013, 10:59:44 PM
Easy there VBS....those old Sachs and Zundapps created the small bore classes. ;)
Title: Hard to find neutral after bottom and top end rebuild
Post by: eprovenzano on July 22, 2013, 06:30:10 PM
Just for grins, here is a finished pic.  Oh BTW, my son has already said, I don't think a 250F it will be enough for me, lets see if we can trade it for a smoker...   ;D  Oh and I'm not a big "sticker" guy, but I do like the liitle one on the front, it says I like Boobies...  :o

Title: Hard to find neutral after bottom and top end rebuild
Post by: Stusmoke on July 22, 2013, 10:07:33 PM
Quote from: eprovenzano on July 23, 2013, 01:30:10 AM
Just for grins, here is a finished pic.  Oh BTW, my son has already said, I don't think a 250F it will be enough for me, lets see if we can trade it for a smoker...   ;D  Oh and I'm not a big "sticker" guy, but I do like the liitle one on the front, it says I like Boobies...  :o



Nuff said :P

My old man got given a breast cancer foundation stubbie holder by a mate whos wife was claimed by it may she rest in peace. Anyway the stubbie says I love boobs, so please take care of yours. Best stubbie cooler ever  8)
Title: Hard to find neutral after bottom and top end rebuild
Post by: _X_ on July 22, 2013, 10:35:42 PM
runnin the rebel battle flag! props.
Title: Hard to find neutral after bottom and top end rebuild
Post by: Coop on July 23, 2013, 11:48:08 PM
Hey no four strokes!

Kidding, since technically your transmission question relates to any bike it's cool. The picture on the other hand  >:-D .

Title: Hard to find neutral after bottom and top end rebuild
Post by: eprovenzano on July 24, 2013, 01:33:35 PM
Quote from: Coop on July 24, 2013, 06:48:08 AM
Hey no four strokes!

Kidding, since technically your transmission question relates to any bike it's cool. The picture on the other hand  >:-D .

 :-*   :D