1984 honda 125m not shifting correctly

[Slayer123]

ive been having these shifting problems lately a lot of the time when i shift up a gear on the three wheeler it will either not shift smoothly, not shift, or it will shift and then pop out of gear not to mention it sometimes takes a couple good forceful pulls to get it in gear. it should shift oh so smoothly idk what the issue would be but i changed the oil in the thing too. any ideas? thanks!

[kb0nly]

Yep... You need to tear into the right side and replace your shift drum stopper, i would BET on it.

I have fixed more then a few of them now. You need a right side gasket, a clutch outer cover gasket, a clutch nut socket, a shift drum stopper arm, maybe the bolt for it too, and a little time.

I would tear it apart first of all and make sure that you didn't break the aluminum boss off the case, that can happen if you get too forceful shifting it, if thats ok and you just broke off the tip of the stopper arm or snapped off its pivot bolt then its about a half hour job to tear it down and put it back together. If you need the manual click on the link in my signature below and download it.

Its not too hard once you get the side off, you just have to remove the clutch outer cover, remove the lock nut, pull the clutch assembly off the crank then pull the gear that it mates with on the transmission shaft, that has a snap ring and you need a snap ring pliers for that, and then you have full access to the shift drum and stopper. If you download the service manual from my server go to page 90 of that pdf file for the parts diagram the stopper arm is upper left.

Only way to know whats going on is to tear into it, and STOP driving it, because you could have parts floating around that can do even more horrific damage. Also clean the oil screen while your in there and you will find plenty of gunk to clean out around that lock nut on the clutch as well, might as well service it at the same time.

[Slayer123]

so i have to tear into the right side... do you mean the side with the back brake or the side with the pull starter? sorry for the stupid question... lol

[kb0nly]

Not a stupid question at all!

The right side is the side with the rear brake pedal, in other words your sitting on it and your right side. Oh depending on if you have factory exhaust or not you might also have to unbolt and remove your exhaust, two nuts at the head and then the bolts that hold the muffler. Spray down the head studs with penetrating oil and let em soak a bit you don't want to break a stud.

You might also want to order a new exhaust gasket/donut if you end up ordering parts or you might have an exhaust leak at the head on re-assembly.

[Slayer123]

is there some sort of a diagram you know of i can use to take this stuff apart because i dont wanna go into this not knowing a lot. thanks!

[Slayer123]

i took the case off and just looked around a bit i didnt take anything apart in there but if the shift drum stopper arm is what i think it is than that looks totally fine. i dont know much about this stuff but i did notice some dings and scratch marks inside there. nothing to major i dont think but they probably shouldnt be there. if you could send me a diagram of the parts or something that would be cool too. but if not i know i can get a repair manual for the thing out my local public library too. and idk if you would want me to take pictures of the inside for you too just let me know. Thanks!

[kb0nly]

The manual with the complete diagram is on my manual server, just click the link below in my signature to take you there and get it!

The diagram is on page 90 of that pdf file from my server.

Well dang, 99.999% of the time a shifting issue on a 125M is the stopper. The only other thing i can think of, change the oil, and adjust the clutch. But compare to the diagram first before your decide there is no problems in there. Could be a bent shift fork too, that would suck, have to split the cases to fix it. I always tell people don't shift it hard, if you have to use force stop and figure out whats wrong because you shouldn't need force to shift it. Using force will just ruin it worst.

[DasUberKraut]

Take pictures. Any of the OEM parts websites like Bike Bandit, Rocky Mountain ATV, Honda Parts House can provide you with an exploded view parts diagram.

Here's what a broken stopper looks like.

[DasUberKraut]

Kb... I like the guys that kick the shifter so hard you'd think they were trying to curb stomp someone. I've witnessed people standing on them to get a machine to shift too.

[kb0nly]

Kb... I like the guys that kick the shifter so hard you'd think they were trying to curb stomp someone. I've witnessed people standing on them to get a machine to shift too.

LOL.. Yep i have seen it also, i barely gotta tap my toes to shift mine.

[barnett468]

Hello


Did this suddenly occur or did it start after something was changed like oil or clutch adjustment etc?

Does it always pop out of the same gear?

Since nothing looks obviously wrong you might try the following. You may not find anything but it’s free and easy to do. Get a friend to help you. These are just suggestions.


1. Put rear end on blocks.

2. Remove spark plug and lay it on head with plug wire connected.

2. Start in neutral.

3. Have friend pull chord as he shifts bike slowly through the gears. You can watch the shift drum etc and see if anything unusual occurs.


If this does not work it might be a bent shift fork as mentioned above.


Check clutch 5,7 and 9 in the OEM parts fiche below for proper function.

http://www.cmsnl.com/honda-atc125m-1...6.html#results


If this looks fine then remove and clean clutch plates.


Inspect clutch hub and basbket for damage that could prevent plates from sliding freely.


If this appears fine and the oil you were using was a new type to this bike and it does NOT say "designed for wet clutch systems" then reassemble and try that. One member had a very similar problem and installed proper oil and it started shifting easily and properly after 15 minutes of riding. Again, cheaper and easier than taking your engine apart.

[Slayer123]

the part i was thinking of that looked fin to me was infront of the gears i didnt even need to take the gears off to get to it. the part in the picture is behind the gears so ill have to take those gears off some how to get to the stopper

[Slayer123]

This is the part i thought was the shift drum stopper but it looks fine it is right in front of all the gears
This is was i think is the shift drum stopper behind the gear
This picture i was just wondering if there was supposed to be a pin in that little hole too im not sure.

[kb0nly]

I can tell you right now your stopper is broke... In your second picture the hook of the spring is on the top of the stopper arm, it should be underneath it providing upward tension, so it broke and the spring came off!

The part you thought was the stopper is part of the shifter assembly, no pin on that other part.

As i described in my other reply to you, you need to remove the clutch assembly, see that cover with the bearing in the center and the two philips screws? Remove that, under that there is a nut, you need the special socket to remove it, remove that nut and the entire clutch assembly comes off. Then the left gear thats over the stopper you just need to remove the snap ring holding it on the shaft, then pull the gear off.

I won the bet... ;-)

[Slayer123]

alright sweet thats a good sign i guess haha. the stopper didnt look broken to me but i wouldnt know what a good one would look like anyways! but where could i get the special socket to take the nut off?