Author Topic: Metro 12/2 rebuild  (Read 5170 times)

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Re: Metro 12/2 rebuild
« Reply #15 on: July 03, 2021, 10:28:24 PM »
My Metro manual has :

"Maximum rod clearance .003"

I'm sure someone else will chime in on this as it has been discussed several times.

You might try the search engine here for more info.

Metro 6/1 turning a ST 7.5 KW gen head
Changfa 1115 turning a ST 15 KW gen head
Ashwamegh 2/25
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32 coupe

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Re: Metro 12/2 rebuild
« Reply #16 on: July 04, 2021, 02:28:20 AM »

Did the rod cap have any shims ?

Metro 6/1 turning a ST 7.5 KW gen head
Changfa 1115 turning a ST 15 KW gen head
Ashwamegh 2/25
John Deere 110 TBL
New Holland TC 30

"I was sitting here reading this thinking what an idiot you are until I realized it was one of my earlier posts !"

George A

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Re: Metro 12/2 rebuild
« Reply #17 on: July 04, 2021, 11:15:16 PM »
Any engine I've ever working on required a bearing clearance of .025-.003 when using oil. A clearance of .003-.004 was required for a greased bearing. This is based on several years of rebuilding/restoring antique flywheel engines and always held true.
I've joined "the dark side"....if it has a spark plug, it's obsolete technology.

Tanman

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Re: Metro 12/2 rebuild
« Reply #18 on: July 05, 2021, 02:49:09 AM »

Did the rod cap have any shims ?

No shims on this side, haven’t tore into other side yet.
Kubota ea300
Metro 12/2

Tanman

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Re: Metro 12/2 rebuild
« Reply #19 on: July 08, 2021, 07:10:38 PM »
My idler gear seems loose. What I mean is I can grab and wiggle it like the hole in the gear and or the idler bolt is worn. I tried tightening the idler bolt as much as I dared, but it didn’t seem to have an effect. Has anyone else had this issue?
Kubota ea300
Metro 12/2

38ac

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Re: Metro 12/2 rebuild
« Reply #20 on: July 09, 2021, 11:12:21 AM »
"loose" is subjective thus I can't be of much help. The bolt/shaft tightens against a shoulder this as you have discovered one can tighten until it breaks and it will not affect the clearances.  There is always some movement in the gear, especially noticeable if twisted on the axis. Actuall clearance with new parts I would guess is .001/ .002".  If correction is needed options are to bush the gear or replacement.
« Last Edit: July 09, 2021, 11:14:14 AM by 38ac »
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Tanman

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Re: Metro 12/2 rebuild
« Reply #21 on: July 20, 2021, 02:03:27 PM »
I decided to take the whole engine apart but have hit a small snag. The camshaft goes through a small bushing in a small casting whole on the side opposite the gears. There is a cam lobe added to that side to drive that sides fuel pump. That lobe has to be removed in order to remove the rest of the camshaft! I have hammered pretty good (4lb hammer and flat punch) to get the pin holding the last cam lobe off and no dice. Does anyone have some tips for getting a very stubborn cam lobe pin out?
Kubota ea300
Metro 12/2

mikenash

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Re: Metro 12/2 rebuild
« Reply #22 on: July 20, 2021, 07:43:36 PM »
Pins are tapered?  Cheers

Tanman

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Re: Metro 12/2 rebuild
« Reply #23 on: July 20, 2021, 07:56:29 PM »
It looks that way to me.
Kubota ea300
Metro 12/2

32 coupe

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Re: Metro 12/2 rebuild
« Reply #24 on: July 20, 2021, 10:31:13 PM »

Yes, they are tapered.

They have been known to beat on both sides. I had one I had to grind the small side flush
before I could drive it out.

Replacement pins are available.


Metro 6/1 turning a ST 7.5 KW gen head
Changfa 1115 turning a ST 15 KW gen head
Ashwamegh 2/25
John Deere 110 TBL
New Holland TC 30

"I was sitting here reading this thinking what an idiot you are until I realized it was one of my earlier posts !"

sirpedrosa

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Re: Metro 12/2 rebuild
« Reply #25 on: July 21, 2021, 09:55:09 AM »
Hi Gentles, TanMan

If it worth take a look at my thread here: https://listerengine.com/smf/index.php?topic=8320.msg100585#msg100585

PAY CAREFULL TO NOT BEND THE CAM SHAFT

Then here: https://listerengine.com/smf/index.php?topic=8320.msg101978#msg101978

And finally here: https://listerengine.com/smf/index.php?topic=8320.msg102710#msg102710

Any other question, be my guest - and off course all other members.

Stay safe
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Petter PAZ1 - Jun 1967, 3HP, sn 416xxxx
Petter PAZ1 - Nov 1979, 3HP, sn 425xxxx
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Deutz MAH 914, 1952 - Zündfix in chamber and go (7Mai2023).

38ac

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Re: Metro 12/2 rebuild
« Reply #26 on: July 21, 2021, 11:36:00 AM »
Yes the pin is tapered. Starting out at square one they come out IF one positively located the small end AND uses the correct near size drift AND hits it hard the FIRST time. However once it has been knocked on and it is now mushroomed to some extent the job becomes more tedious. First you need to positively located to small end. Then grind it flush with the cam lobe to remove as much mushroom as possible. Then grind the tip of a punch so it is slightly smaller than the pin. Then heat the cam lobe with a torch, must be hot, not warm, but not red hot. Quickly grab the punch and hammer and hit it good ONCE. 99 times it will move, if not do NOT keep on hitting it as you are doing nothing but mushrooming the pin. Heat it again and give it another hit.  I have had one case were I had to cut the lobe off the cam, it was a very neglected engine that another person had butchered previously.  I keep the pins here or order them from McMaster Carr.
« Last Edit: July 21, 2021, 11:40:57 AM by 38ac »
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Tanman

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Re: Metro 12/2 rebuild
« Reply #27 on: July 22, 2021, 12:01:51 AM »
Thank you for the guidance and responses for the cam lobe everyone. Also, thank you 38ac for getting those exhaust valves and guides shipped to me so fast! They look great.
Kubota ea300
Metro 12/2

Tanman

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Re: Metro 12/2 rebuild
« Reply #28 on: August 25, 2021, 02:34:02 PM »
Okay so I'm having a lot of trouble getting that cam lobe off, not giving up just a little stuck. On top of that, I noticed that the other end of the camshaft (side with the gears) has a pretty good wobble to it. What is the best practice to straighten that out? (I couldn't find a bent cam or bent camshaft thread). Thank you.
Kubota ea300
Metro 12/2

32 coupe

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Re: Metro 12/2 rebuild
« Reply #29 on: August 25, 2021, 10:16:52 PM »

Once you remove the entire cam set it on some parallel blocks rotate and check to see if it's bent.

Mine was out a little and once I located the high spot a wack with a hammer will straighten it.

The center carrier for the cam on mine was sloppy in the block. I had to shim the  center carrier
to remove the excess play. My unit is an Ashwamegh so yours may be different.

I'm sure someone will chime in with more/better info.

Metro 6/1 turning a ST 7.5 KW gen head
Changfa 1115 turning a ST 15 KW gen head
Ashwamegh 2/25
John Deere 110 TBL
New Holland TC 30

"I was sitting here reading this thinking what an idiot you are until I realized it was one of my earlier posts !"