PX Gear Change Issue
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Hooked
'62 TV175, '70 GP-RB250, '74 Rally 200. '03 PX200E
Joined: 24 Apr 2012
Posts: 323
Location: South Africa
Tue Sep 10, 2019 11:46 am quote
Hi Guys

Havenít been around here for a while and Iím glad that I recognize some familiar names. I need help on gear change issues on my PX200 Millennium. The gear change from when I bought the scooter has always been a little stiff, especially going down from 3-2-N.

1) Thinking it was the cables, I changed both the outers and inners. The outers were original as they had the metal clamp holding the two gear cables together. I used the old outers to pull in the new ones so the routing of the cables should be correct. To my dismay, the gear change issue is allot worse with the new cables. The scooter is now not ridable and extremely difficult to change gear.

2) I removed the selector box, moving the plunger by hand moves the cruciform nice and freely through all the gears

3) I thought perhaps the gear change lever was binding with the headset and added a spacer as shown by the pencil

4) In installing the spacer, I had to strip down the gear change handle-bar and did not see any issues.

5) I swapped out the selector box with one from another working engine and the problem is the same.

I am stumped on what to look at next. Please help.



Last edited by Vespigi on Tue Sep 10, 2019 7:06 pm; edited 1 time in total
Hooked
'62 TV175, '70 GP-RB250, '74 Rally 200. '03 PX200E
Joined: 24 Apr 2012
Posts: 323
Location: South Africa
Tue Sep 10, 2019 11:51 am quote
Some pics

20190910_165605.jpg

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20190910_165642.jpg

20190910_204708.jpg

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Thought was binding here prior to adding spacer

20190910_204836.jpg
Added spacer here

20190910_204845.jpg



Last edited by Vespigi on Tue Sep 10, 2019 12:01 pm; edited 1 time in total
Hooked
'62 TV175, '70 GP-RB250, '74 Rally 200. '03 PX200E
Joined: 24 Apr 2012
Posts: 323
Location: South Africa
Tue Sep 10, 2019 11:58 am quote
For some reason the You Tube videos I posted in my original message are not playing. Please copy and paste the links below to your address bar in your browser and remove the asterisk in the beginning

*https://youtu.be/Wd2YMLA38aA

*https://youtu.be/0fqo0-K6Du4
Addicted
'64 Motovespa 150S (177) , '64 V90
Joined: 27 Mar 2013
Posts: 570
Location: S.Salem, NY
Tue Sep 10, 2019 1:16 pm quote
worn out cruciform and/or chipped corners on the gears causing the cruciform to bounce off the gears instead of engaging ?
Addicted
Old douglas ..smallie with polini 115..super with nasco 177
Joined: 07 Nov 2013
Posts: 559
Location: New Zealand
Tue Sep 10, 2019 1:42 pm quote
try this
Hook up the gear selector to the cables etc.adjust it all nice....and leave it hanging intact........now go thru the gears at the handle and" feel"

This will establish if it isa slector/cable issue vs an internal cog/cruiciform/tube issue.

It should click nicely thru all the notches on the batwing while it is hanging in the air

If not it will be a cable or handle bar tube issue

another diagnostic is to disconnect the cables at the head set end and again Feel" for binding in the tube

I have had to sand the rust off selector tubes and grease it before it would rotate with out any resistance

good luck
Addicted
GL, PK, PE200
Joined: 24 Apr 2012
Posts: 661
Location: Deep in the heart of Texas
Tue Sep 10, 2019 1:54 pm quote
The length of the outer maybe the problem. If it seems you're sure about the handlebar moving properly and sure the selector rod is going threw all the gears when the rear wheel is rolling and you're sure its not the selector box or components inside, the next thing to check is the cable length and/or routing. Just go down the list of connections and moving parts from handlebar down to the selector rod like you're doing. If the rod is not going through the gears when the rear wheel is jacked up and spinning you may have a cruciform problem but I'll check everything first before thinking opening the motor is the solution.

Good luck!
Hooked
'62 TV175, '70 GP-RB250, '74 Rally 200. '03 PX200E
Joined: 24 Apr 2012
Posts: 323
Location: South Africa
Tue Sep 10, 2019 7:20 pm quote
Thanks for the reply
Moto64 wrote:
worn out cruciform and/or chipped corners on the gears causing the cruciform to bounce off the gears instead of engaging ?
The cruciform is relatively new with around 1000km of usage so unlikely this is this issue
Hooked
'62 TV175, '70 GP-RB250, '74 Rally 200. '03 PX200E
Joined: 24 Apr 2012
Posts: 323
Location: South Africa
Tue Sep 10, 2019 7:33 pm quote
Re: try this
Thanks for the reply
Bluecati wrote:
Hook up the gear selector to the cables etc.adjust it all nice....and leave it hanging intact........now go thru the gears at the handle and" feel"

This will establish if it isa slector/cable issue vs an internal cog/cruiciform/tube issue.

It should click nicely thru all the notches on the batwing while it is hanging in the air

If not it will be a cable or handle bar tube issue

I have tried this and the batwing does click into all positions. However, I think the force needed to twist the handlebar is more than what I remember doing this in the past on other scooters.

When re-installing the selector box something seems to jam up or bind.
Bluecati wrote:
another diagnostic is to disconnect the cables at the head set end and again Feel" for binding in the tube

I have had to sand the rust off selector tubes and grease it before it would rotate with out any resistance

good luck
When I added the spacer I greased up everything, the tube with gear handle moved freely when not connected to cables.
Hooked
'62 TV175, '70 GP-RB250, '74 Rally 200. '03 PX200E
Joined: 24 Apr 2012
Posts: 323
Location: South Africa
Tue Sep 10, 2019 7:43 pm quote
rowdyc wrote:
The length of the outer maybe the problem. If it seems you're sure about the handlebar moving properly and sure the selector rod is going threw all the gears when the rear wheel is rolling and you're sure its not the selector box or components inside, the next thing to check is the cable length and/or routing.
I did not check the length of the new outers compared to the old ones. I really don't want to remove the tank and pull the new outers to check the length. If the new outers are longer could this cause all these problems?

Routing should be right, the old outers that I pulled were factory original with clamp holding both gear cables together. I used the old outers to pull in the new outers so routing is the same.
rowdyc wrote:
Just go down the list of connections and moving parts from handlebar down to the selector rod like you're doing.
I feel like I have run out of moving parts to check and going back to things that I have already looked at
rowdyc wrote:
If the rod is not going through the gears when the rear wheel is jacked up and spinning you may have a cruciform problem but I'll check everything first before thinking opening the motor is the solution.
While the selector box was off, I lifted the rear wheel off the ground using a trestle jack. Spinning the rear wheel and moving the selector rod by hand I could move the cruciform freely through all the gears. Cruciform is also relatively new.
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