Moto4 Shifting

[KIWINZ]

Hello

My son scored a free Moto4 - late 80s from the looks of it. I don't know anything else about its history as the owner wasn't there when i picked it up. Can't see the VIN number as its a bit rusty.  He cleaned the carb and then with some either it started and still starts first pull.  Its runs really nice - not rattles etc.  Goes forwards well and the brakes work fine so it looks like a keeper, However, we have only managed to get it into reverse once.

1) it won't shift down into what seems like where first would be - 2nd and upwards only. The changes between gears is fine.  No crunching or missed gears - just no first gear.  2nd gears appears to be as low as it will go

2) the clutch - when you hold the gear lever up or down works (only the second ATV we have had.  Other is a Quadrunner which doesn't have this feature)

3) no neutral light - will start when no in neutral - should it do that?

4) the one time we did get it into reverse the neutral and then the red (reverse) lights worked. Swapped easy between forward and reverse - when it went into second, it didn't return to first or neutral

5) checked the clutch adjust on the RHS - seemed fine to me.  When i turned the screw back 1/8 it was where it was to start with.  Clutch doesn't slip.  The bike will move forward is all gears.

 

Any help would be appreciated

 

Thanks

 

Andrew

[Ajmboy]

Congrats on the find! Is your shift selection like the video below?

 

[KIWINZ]

Yes it is.  That's the video I used to figure out how to select reverse.  Only managed it one.  I cant select first or neutral.  I know they are in their somewhere as i managed once.  

 

I did some more looking last night and came across this picture and description on Facebook.  It appears that the bolt holding the "segment - 5H0-18185-01-00" can come loose and/or the keyway on the drum breaks which means that the shift drum wont rotate correctly and therefore gears wont be selected.  Looks like I have to take the RHS cover off and the clutch basket out. 

[Gwbarm]

I have seen this happen so many times its like the loctite they used didnt hold up over time, i have gotton away with just refitting the keyway and reinstalling the bolt before, but other times i had to do what you are planning.

[KIWINZ]

Hi
 

Turns out it was this part 90508-29570-00 - Yamaha OEM Part 90508-29570-00 SPRING, TORSION which returns the gear selector shaft to a return position - not neutral