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Balance Shaft Removal

2740 Views 19 Replies 11 Participants Last post by  tiggerlator, 
A
Hey guys,is there any way to remove balance shaft bearing and balance shaft without remove the engine from the bike ?
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R
Will be a engine out and full strip down there is 2 balance bearings
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A
yes i know that there are 2 bearings .but i want just to remove the one and the balance shaft without remove the whole engine from the bike ... Is it possible to pull out the bearing and the shaft from the crankcase with engine on the bike ?

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sobriety
No
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A
I recon you could if you butchered the case around it. Mine just pulls out of the bearings easily. Maybe try heating up the aluminium with some oxy acetylene, and shocking it up like a blind bearing puller?
Worth a shot if you really want to remove it

Sam
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Z
My gut feeling is no after looking at the crank case halves I have here.
But I have the Engine repair manual! If that is any good to you.
http://s000.tinyupload.com/?file_id=55414192529980112093
had to upload to there as the file is to big for the forum attachment thing
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T
You can't pull out the balancer shaft without splitting the cases.There is a shoulder that the bearing sits on.so physically impossible.
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P
You can remove the balance shaft and the outer bearing quite easy without splitting the engine, the inner bearing is a little more tricky but can be done
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T
[email protected] said:
You can remove the balance shaft and the outer bearing quite easy without splitting the engine, the inner bearing is a little more tricky but can be done
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You cut remove the inner bearing without splitting cases.it's a blind hole.
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torquefilthy said:
You cut remove the inner bearing without splitting cases.it's a blind hole.
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Do you mean "you can't" rather than cut ?

You can remove the inner bearing, granted it is hard and most won't have the tool but it can be done. The outer bearing is only held in with a washer and a M5 countersunk screw.
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R
Would you be able to get a bearing puller in there? To make it easyer could heat the case up on other sidecwere bearing is.
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Rs125 crazy said:
Would you be able to get a bearing puller in there? To make it easyer could heat the case up on other sidecwere bearing is.
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To start off remove the the M5 screw that is holding the LH bearing in place, refit the C-clip on the balance shaft apply heat around the case where the bearing is and then pull on the balance shaft / c-clip with mole grips or big pliers and it should pull out with the bearing. Then you will need a internal bearing puller to pull the RH bearing out, that is the hard one to do.
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T
[email protected] said:
Do you mean "you can't" rather than cut ?

You can remove the inner bearing, granted it is hard and most won't have the tool but it can be done. The outer bearing is only held in with a washer and a M5 countersunk screw.
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Yes I meant can't.Think I'm going to have to look at a spare set of cases to familiarize myself.it's been a while.Very interested in extracting this bearing without splitting cases.I know you do this on a daily basis.good information Paul.
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A
2
I split the cases and i removed the bearings and the balance shaft ..The balance shaft is on very bad condition so i will buy a new one but i just noticed that there are two types of that shaft.Mine is as the first one..both of them are for rotax 122 engine..But why they are different ?Can i use the second one on my engine?

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Apostolis said:
I split the cases and i removed the bearings and the balance shaft ..The balance shaft is on very bad condition so i will buy a new one but i just noticed that there are two types of that shaft.Mine is as the first one..both of them are for rotax 122 engine..But why they are different ?Can i use the second one on my engine?
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They look completely different to me the one on the right even looks shorter guessing it must be wrongly listed or something just my 2 cents stick with one that looks the same as the one you have
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xchris
3
just had the inner/blind balance shaft bearing failed on my 122. I managed to get both bearings and shaft out without splitting cases, but it wasn't so easy. The clutch side bearing pulled out easy along with the shaft. for the inner one I adapted a blind bearing puller for long reach and heated the casing (near the flywheel). Once the bearing came out of its seat I then realised it wouldn't fit through the hole in the clutch side casing, so I had to file about 1mm off the lip around the clutch side casing to allow the inner bearing to pass through it, theres still plenty left for the outer bearing to seat against.
Hope this helps someone out to know
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maddad
Interesting to say the least ,looking at the state of the motor and the amount of swarf around my guess is other bearings will soon fail .I was certainly on way of doing it that's for sure 😃
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pego30
xchris said:
just had the inner/blind balance shaft bearing failed on my 122. I managed to get both bearings and shaft out without splitting cases, but it wasn't so easy. The clutch side bearing pulled out easy along with the shaft. for the inner one I adapted a blind bearing puller for long reach and heated the casing (near the flywheel). Once the bearing came out of its seat I then realised it wouldn't fit through the hole in the clutch side casing, so I had to file about 1mm off the lip around the clutch side casing to allow the inner bearing to pass through it, theres still plenty left for the outer bearing to seat against.
Hope this helps someone out to know View attachment 19291
View attachment 19292
View attachment 19293
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Where there’s a will
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xchris
I recommend to put a piece of cardboard over the gear shafts inside the gearbox, this catches most of the swarf from the file and if the bearing comes apart nothing can drop down, also wrap the clutch bearings and I flushed out the gearbox with auto trans fluid after and cleared the oil ports of chewed nylon from the gears.

saved a lot of time and money over a full rebuild just for one bad bearing
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tiggerlator
why not do it properly instead of butchering your engine.
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