Author Topic: 3ma balance shaft  (Read 6019 times)

Tzr3ma

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3ma balance shaft
« on: December 21, 2019, 06:35:08 PM »
Hi before I take the engine apart is it easy to set up the balance shaft back up on install  ?:-|
Thanks

Warwick

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Re: 3ma balance shaft
« Reply #1 on: December 21, 2019, 07:34:03 PM »
Yes, very straightforward. Removing the nut on the end gear will probably be the biggest challenge. Remembering that it is a reverse thread will help... :) 
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Tzr3ma

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Re: 3ma balance shaft
« Reply #2 on: December 22, 2019, 08:38:58 PM »
Ok thanks Warwick what about putting it back and keeping it in balance  ?:-|
Thanks

Warwick

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Re: 3ma balance shaft
« Reply #3 on: December 22, 2019, 10:41:58 PM »
the central cog on the balance shaft is marked with a punch holes that should be lined up with the punch hole in the cog on the drive shaft to ease matching when reassembling. The cogs fit on the shaft with woodruff keys. Just take a picture before disassembly to record the position of the cog and the end weight if unsure.   (-P)
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Steveog

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Re: 3ma balance shaft
« Reply #4 on: December 23, 2019, 08:10:00 PM »
Warwick explained things well. Here's a pic of the cogs discussed and the punch-marks that need to be aligned.

Most of these visual instructions are in the maintenance manual available in the "Resources" section.

Good luck.

Steve
« Last Edit: December 23, 2019, 11:44:51 PM by Steveog »
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Tzr3ma

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Re: 3ma balance shaft
« Reply #5 on: December 23, 2019, 11:18:06 PM »
 (-P) (-P)

Edd

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Re: 3ma balance shaft
« Reply #6 on: January 06, 2020, 01:45:00 PM »
Hi

Not as easy as in Steves pic that looks like a 3xv balance shaft :D. However if you mark the gears on the side with white paint and use a torch you can see if it is alligned once you drop the crank in. It does take a few goes at it but you will get it. ;)

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Steveog

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Re: 3ma balance shaft
« Reply #7 on: January 06, 2020, 07:19:53 PM »
Thanks for the clarification, Edd. Yes, I'm showing the punch marks from a 3xv.

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Warwick

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Re: 3ma balance shaft
« Reply #8 on: January 06, 2020, 08:22:19 PM »
It's easiest to check alignment of the 3MA crank and balance shaft gears if you remove the inspection plate on the underside of the motor - that's its sole purpose as far as I can tell? The plate gasket is NLA though so you will need to make a replacement - standard generic gasket paper is fine as it's not under any pressure. That's what I used in any case.
« Last Edit: January 07, 2020, 12:05:30 AM by Warwick »
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Tzr3ma

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Re: 3ma balance shaft
« Reply #9 on: January 25, 2020, 08:00:46 PM »
Hi  trying  to put balance shaft back forget to take picture  :-[ how balance weights were setup on shaft with cog there are three different points on shaft to fit with woodruff key

Warwick

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Re: 3ma balance shaft
« Reply #10 on: January 27, 2020, 09:37:31 PM »
The removable weight is oriented 180 degrees from the fixed weight IIRC? (pretty confident).

You're wishing you'd taken a pic or made a note now, aren't you?  :)) :o (-P) 
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Warwick

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Re: 3ma balance shaft
« Reply #11 on: January 27, 2020, 11:49:32 PM »
Isn't there only one way to mount the cog? I'm struggling to remember, but I don't recall having to think about that bit. It's a good few years since I rebuilt mine though I'm afraid. Someone else may have a more recent/better memory?     
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Tzr3ma

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3ma balance shaft
« Reply #12 on: January 29, 2020, 07:52:31 PM »
Hi can't fit weight 180 degrees as shown in picture do I line up line on weight  with dot on shaft  ?:-|and line up  cog as shown in picture the work shop manual is not clear
Just realised pictures did not upload will try to upload later
« Last Edit: January 29, 2020, 08:02:20 PM by Tzr3ma »

Tzr3ma

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Re: 3ma balance shaft
« Reply #13 on: January 29, 2020, 08:14:19 PM »
Hi can't fit weight 180 degrees as shown in picture do I line up line on weight  with dot on shaft  ?:-|and line up  cog as shown in picture the work shop manual is not clear
Just realised pictures did not upload will try to upload later
« Last Edit: January 29, 2020, 10:21:58 PM by Tzr3ma »

Warwick

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Re: 3ma balance shaft
« Reply #14 on: January 29, 2020, 10:03:20 PM »
You need to be using the 'reply' option (not 'quick reply') I think? Then you should see the option to Attach a picture or file to bottom of post under the text box you are typing in. Note the limits to file size - you might need to reduce the image size/resolution if they are large or high res?
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