Puch e50 spitting clutch bell circlip at hihi rpm

At 12000+ rpm my bike keeps popping off the circlip that holds the clutch bell.

Before I thought it was down to incorrect sized circlip but had a few now and it’s not that. Any thoughts ?

Re: Puch e50 spitting clutch bell circlip at hihi rpm

It seems to happen more when I rev out on the stand. But when riding the bike also happens.

Usually ending by unbolting the clutch itself and jamming the starting lever

I had thought the shim was pressing heavily on the circlip. So made the top shim everso thinner.

Is this crank walk? Tomorrow once the engine is very warm I will try pressing on the flywheel and look for movement

Also due to this happening my clutch has lapped its self to the crank rather well

Re: Puch e50 spitting clutch bell circlip at hihi rpm

I had this same issue. One theory is the bell was a bit out of true, or some sideloady business with the helical gears. Straight cuts solved it

Re: Puch e50 spitting clutch bell circlip at hihi rpm

Yea its the way the gears are cut. The og main gears put side load on the bell and it makes the circlip pop out. Iv never experienced this issue before though in any of my high rpm kitted bikes.

Are you using a 15mm circlip or did you go down the the hardware store and buy the close American size? Where the circlip goes could be defective too

Re: Puch e50 spitting clutch bell circlip at hihi rpm

> Rocco Taco Wrote:

> -------------------------------------------------------

> Yea its the way the gears are cut. The og main gears put side load on

> the bell and it makes the circlip pop out. Iv never experienced this

> issue before though in any of my high rpm kitted bikes.

>

> Are you using a 15mm circlip or did you go down the the hardware store

> and buy the close American size? Where the circlip goes could be

> defective too

Yeah I’ve used 15mm I’m over in U.K.

Re: Puch e50 spitting clutch bell circlip at hihi rpm

Jack Hernandez /

Once the circlip pops a couple of times out of the groove, it rounds the edge of the ring it seats in. From there the chances of it popping out again increase dramatically. The wear on your crank doesn't ever get better, so a new crank would seal the deal.

Re: Puch e50 spitting clutch bell circlip at hihi rpm

after getting the bike suitably warm i threw on a latex heatproof glove nd wobbled the igniton side their did feel 3-4mm of movement in and out

Re: Puch e50 spitting clutch bell circlip at hihi rpm

thats quite a bit.

Re: Puch e50 spitting clutch bell circlip at hihi rpm

You could maybe turn the engine over with a drill and use a small hack saw blade to cut the groove a little .

Re: Puch e50 spitting clutch bell circlip at hihi rpm

i'm wondering if maybe the crank bearings have worn also, they were cheapo ntn ones, i have a set of nachi's here i may swap in and see if that makes much difference?

Re: Puch e50 spitting clutch bell circlip at hihi rpm

Matt Mahloch -- MBM Customs /

A few things. I agree that the helical gears create a side load the puts pressure on the clutch he’ll snap ring causing it to pop out of its groove. This has happened to me before and once it pops off once like has already been stated it will continue to do it. This helical side load also puts pressure on the crank bearings causing them to ware. I’d be curious to know when you take it apart if the clutch bell is wearing on the case. If it is I’d say the crank bearings being loose allowed the bell to hit the cases putting excessive force on the snap ring causing it to pop out. The crank play shouldn’t have anything to do with the bell unless this is what’s happening. If you take it apart to put new bearings on I’d replace the crank too. You can run 2 snap ring bearings on the crank and cut a second groove to help with the loading on the crank bearings. I was going to install a circle clip instead of a snap ring but went with straight cut gears instead. I hadn’t sourced a circle clip but here is a link, not sure if any measure properly but if you don’t know what circle clips are it gives you an idea. Make sure the bell is shimmed tight so that side load can’t build up momentum and knock it off. I’ve always lost the clip with a high rpm stall, not spinning high rpm.

https://www.mcmaster.com/circle-clips

Re: Puch e50 spitting clutch bell circlip at hihi rpm

Matt, which of the ones on that page are the circle clips you're talking about? The ones at the top are the type I've used and popped out before. Do you mean the spiral retaining rings? Those look interesting.

Even with dual snap ring crank bearings I had the circlip spitting issue, until I went to the straight cuts. The dual snap rings helped a lot with that crank walk tho, the in & out of the flywheel. Since doing that I'll blow the big end bearing on the crank from sustained rpm before the crank bearings go

That'd be real cool if a different design retaining ring helped with the circlip jumping. I don't wanna and can't afford to put straight cuts in every ripper motor lol

Re: Puch e50 spitting clutch bell circlip at hihi rpm

Matt Mahloch -- MBM Customs /

Jordan - that didn’t copy and paste right and I never checked it. The spiral ones, I’d thought about using them but never did. I like the idea. I agree 2 bearings won’t do anything for the clutch bell, just the crank.

Re: Puch e50 spitting clutch bell circlip at hihi rpm

On my race bike I just shimmed it 100% to the clutch hub. No more circlip popping off. I also have reverse cut gears so I didmt have this problem to begin with on thos particular engine. But I wanted to make Damn sure my bell wouldnt flop off and ruin my nice gear set.

Re: Puch e50 spitting clutch bell circlip at hihi rpm

> Daniel '' Wrote:

> -------------------------------------------------------

> On my race bike I just shimmed it 100% to the clutch hub.

yeah to me that sounds like the ultimate fix for this

if your crank is walking (3-4 mm, yeah, its walking) you gotta fix that. lots of stuff posted on here, dual snap rings, retaining compound, retaining compound and peening the bearing journal...

i've seen engine builders sandblast the bearing journal as a way of peening them, the shot or sand raises them up and the texture gets the bearing to bite. similar to the way knurling a valve guide works to tighten it up.

Re: Puch e50 spitting clutch bell circlip at hihi rpm

reshimmed my bike and never had this issue again, had to alter my shimmingbing by 1mm mind, i think its new clutch/crank time

Re: Puch e50 spitting clutch bell circlip at hihi rpm

If I still had an e50 with this issue I'd do something really simple.

Cut the slot 1mm deeper with a thin hacksaw or dremel cutting disc and use a 1mm smaller clip, or a nominal sae clip that's the next size down from the stock metric clip (edited)

Re: Puch e50 spitting clutch bell circlip at hihi rpm

> JBOT Admin Wrote:

> -------------------------------------------------------

> If I still had an e50 with this issue I'd do something really simple.

>

> Cut the slot 1mm deeper with a thin hacksaw or dremel cutting disc and

> use a 1mm smaller clip, or a nominal sae clip that's the next size down

> from the stock metric clip

It hasn’t happened since. Luckily. If it does I will follow this advice though

Re: Puch e50 spitting clutch bell circlip at hihi rpm

Circlip on circlip? Why would that work any better?

Re: Puch e50 spitting clutch bell circlip at hihi rpm

Wat? One circlip that sits deeper in a slot

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