Centrifugal clutch seized on crankshaft

[Bigjon9976]

Hello fellow riders!

I have a 1984 ytm 225 that I’ve been bringing back to life here and there. I’ve also been riding quite a bit lately and having a blast. However...

I am trying to change the centrifugal clutch, but I cannot get the clutch drum or clutch off the crankshaft. I’ve tried all methods I can think of so far and still can’t get it off (lined up the clutch basket so the centrifugal clutch would slide out, beat the mess out of the clutch drum with a dead blow and claw while applying pulling force, bent the clutch drum using a 3 jaw puller and broke the puller, did a small amount of prying but I didn’t like that very much so I stopped before it got nasty).

Only thing left I think of is applying heat to the clutch drum. I really don’t want to destroy the crankshaft just to address this clutch issue, but it’s getting really close to that. I’m assuming the splines must be twisted or otherwise distorted. Either that or I have to be doing something wrong because it is not supposed to be this hard to slide out the housing and inspect/replace as necessary.

Additionally, a yellow spring was laying in the bottom of the clutch cover when I pulled it. I’m assuming this spring goes to the clutch adjustment arm. Can anyone shed some light or maybe some similar experience? I can’t find any pictures or videos showing the inside of the clutch cover with the clutch adjuster setup. I can post any requested pictures that may help.

Thank you guys in advance for any assistance!

[Bigjon9976]

For anyone checking this post, I finally got the centrifugal clutch off today. Had to cut through the clutch housing and clutch assembly to break the bond. Then used a puller and impact to get the clutch off (welded two bolts to either side of the clutch assembly so I could use the puller. Ridiculously hard and fought me all the way! New parts ordered and I’m excited to see an increase in performance.

I still don’t know where that little yellow spring came from though. I would warmly welcome any ideas or assistance. I will also happily share any photos that could help or any photos of the carnage and aftermath of this little adventure.

Seems like maybe no one is really using this site based on the amount of replies I’ve received lol. Hope to hear from someone in regards to that little yellow spring.

[El Camexican]

First of all, welcome to the site.

Secondly, new comers usually post in the new members forum the first time and go through a probation period before the can post elsewhere.

Thirdly, hardly anyone posts in this section. Most of the eyes are in Trikesylvania.

Fourthly, Yamaha questions don’t draw a crowd like Honda questions do. Ask a Honda question and you’ll have an answer the same day.

And finally, you didn’t put a photo up. Probably still restricted, but it would have helped.

So, are you sure that first nut wasn’t a left-hand thread? I can’t remember, it’s been a long time.

If you could post a photo of the spring we can probably identify it. There are only a few in the engine.

[Bigjon9976]

Thank you for the warm welcome ��
Ya, I had to wait a little while before it would let me post anything.
I thought this was a part of trikesylvania. I may have been confused. I’ll take a closer look at where I’m posting next time.
I agree and I kind of expected a smaller Yamaha crowd.
I will try and post some pics. We’ll see if it will let me ��
The nut holding the centrifugal clutch was normal thread; lefty-loosey. Wasn’t too bad with the impact. But getting the clutch to slide off was ridiculously difficult.

Thanks again for replying! ��

[Bigjon9976]

https://imgur.com/a/cxZiS1p

[Bigjon9976]

Alright, so you can see the carnage. I had to cut through the clutch and clutch drum all the way up to the crankshaft to break the clutch’s grip on the splines. Then I was able to use the puller with an impact to get the clutch to finally come off. It still wasn’t that easy after cutting through the clutch and clutch drum. The rust you see is from the old parts sitting outside on the work table. They were not rusted like that when I pulled them off.

Moving on, all new parts are ordered and on the way. Excited to get this back together!

You can see the little yellow spring in a couple of pics. Any clue where this spring would go? Or does this spring even belong in there? Wouldn’t surprise me if it’s foreign and doesn’t belong to the trike Lol!

[El Camexican]

When I open your attachment its just a dark blue background.

[thefox]

You really did a number on the clutch! I have run into some putting up a fight but never that bad.

The spring looks like it’s one of the little springs that goes on the gear behind that clutch housing. There are 6 spring (every-other on also has a metal spacer block in them). There is a metal plate that covers the gear which drives the counterbalanced.

Man, it’s been a few years since I had a YTM motor apart, I’m a little rusty with the details.


Sent from my iPhone using Tapatalk

[El Camexican]

You can see the little yellow spring in a couple of pics. Any clue where this spring would go? Or does this spring even belong in there? Wouldn’t surprise me if it’s foreign and doesn’t belong to the trike Lol!

Ok, opened the photos on my phone. The only springs I know of that look similar are in the two clutches. Some clutch baskets use springs in the backing plate to absorb shock, but I don’t know if yours uses them as some smaller engines use rubber blocks. If it did come from there I don’t know how it got out as there is a riveted plate keeping them in place.





Did you compare it to the ones on your clutch’s?

[ATC King]

It looks like thefox is spot on. Although, how the spring go to wandering about on it's own is a little frightening.

Part #16

https://www.partzilla.com/catalog/ya...nkshaft-piston



That clutch looks baked! Like someone left it in fourth or fifth gear on a regular basis, taking off from a dead stop. Someone who never drove anything other than an automatic.

If the oil got that frizzle fried around the clutch, it's now wonder it was glued on.

[Bigjon9976]

Not sure why it was doing that and not showing the pics.

[Bigjon9976]

Ya, I tried beating it off, 3 jaw puller, welded a couple bolts on to use a universal puller (that’s what you see in the pics), everything. Finally, I decided I would have to cut the clutch and drum. Ran out of options and had to hack at it due to the limited space with the cutoff wheel in there.

Ah, ok. I didn’t know there was a spring or set of springs behind that gear!

[Bigjon9976]

Ya, I did take the clutch basket out because I will have to clean everything after working in there. Also, I wanted to inspect the clutch disks while I’m in there as well as the shifting components. Didn’t match the size of the yellow spring I found on the clutch cover so I will be digging deeper. I also looked at the centrifugal clutch and it uses two really large springs that also didn’t match the size of that yellow spring.

[Bigjon9976]

Ya man, that clutch and clutch drum were really bad. When I first opened the clutch cover and looked at the clutch drum, it was blued all the way around so I know that bad boy got hot to change the color like that. That was probably the original clutch and clutch drum of I was to guess lol. I’ve been looking at the diagrams, but didn’t know that was the spring I was looking for. Sounds like I need to go in a little deeper and inspect what happened in there. I hope I don’t need to order more parts. I’m ready to get her back together and ride! I’ll post my findings when I get some time off work to mess with it some more.

[Bigjon9976]

I really appreciate all the help from everyone so far. I will keep updating this post until it is fixed and running again. I hate those threads that leave you in suspense lol. Here’s a couple pics of the new clutch and clutch drum. I took them out to test and make sure everything fits properly (the centrifugal clutch is a different style with the small springs) and everything does.

https://imgur.com/gallery/bPqIFBD

To be continued....