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Tecumseh Rebuild Options? Or Opinions?


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#1 HowardsMF155 OFFLINE  

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Posted August 20, 2013 - 08:46 PM

So, I've got a couple of Massey's.  One, I repowered with a Harbor Freight predator/Honda clone.  While I am reasonably happy with the power and the way the engine runs, I'm less happy about the lack of a charging coil.

     So that would leave trying to rebuild a Tecumseh HH120.  I've found a connecting rod with undersized journal on Ebay, found a complete gasket set, and found an OH120 piston which is .010 over.  Parts alone will run close to @200, then another 100 to 150 for boring, grinding, and re-doing the valves and seats.  Before spending $300 or more plus the time, I'd like to hear from folks here who might have done this.  Also, will that OH120 piston work in a HH120?

 

Thanks in advance,

Howard



#2 superaben OFFLINE  

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Posted August 20, 2013 - 08:53 PM

I am seeing a possibility of two numbers for an OH120 and an HH120 piston.  That doesn't mean anything, both are used interchangeably.

 

I can check my old manual for you.  What is the part number for your piston and the HH120's model number?  

 

Ben W. 


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#3 HowardsMF155 OFFLINE  

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Posted August 20, 2013 - 09:01 PM

HH120 120045D is the number I found on the shroud of the engine.

The piston number is 34547 I think.


Edited by HowardsMF155, August 20, 2013 - 09:04 PM.


#4 DH1 ONLINE  

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Posted August 20, 2013 - 09:10 PM

The HH120 has a bore of 3.5"

The OH120 has a bore of 3.125"

 

Different engines, displacements.

The OHV engine does not need to be as big to make the same HP

 

So from what I see the OH120 piston will not fit a HH120

 

 

I get this info from the Tecumseh engine service manual.


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#5 TerryD OFFLINE  

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Posted August 20, 2013 - 09:21 PM

I'm in the same boat with an HH100 in my MF10 that I picked up a couple months ago. So far I've invested about $100 in belts, seals, carb repairs and so forth. I will probably continue to do what is necessary to keep the engine going another 40 years since they aren't very common. Are yours SSI? Replacement SSI's run $150+, and there are workarounds, but I hope to keep mine OE as long as possible.

Best of luck in your quest for parts.
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#6 HowardsMF155 OFFLINE  

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Posted August 20, 2013 - 09:30 PM

Yes, both engines have the SSI modules, which is fine as long as they keep running.


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#7 TerryD OFFLINE  

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Posted August 20, 2013 - 09:34 PM

Yep. One day we may all have to start horse trading parts.
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#8 OkieGt OFFLINE  

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Posted August 20, 2013 - 09:57 PM

So, I've got a couple of Massey's.  One, I repowered with a Harbor Freight predator/Honda clone.  While I am reasonably happy with the power and the way the engine runs, I'm less happy about the lack of a charging coil.

     So that would leave trying to rebuild a Tecumseh HH120.  I've found a connecting rod with undersized journal on Ebay, found a complete gasket set, and found an OH120 piston which is .010 over.  Parts alone will run close to @200, then another 100 to 150 for boring, grinding, and re-doing the valves and seats.  Before spending $300 or more plus the time, I'd like to hear from folks here who might have done this.  Also, will that OH120 piston work in a HH120?

 

Thanks in advance,

Howard

In a new york minute. That engine lasted almost 4 decades, a good rebuild could get you another 4 decades. The best money you will spend. That fresh 12hp Tecumseh will blow the doors of any 12hp clone engine. Done right as you describes is the cheapest routw in the long haul, I doubt you will be sorry


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#9 MH81 ONLINE  

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Posted August 20, 2013 - 10:30 PM

I'm looking down the barrel on the engine on the Scrap Massey. She lost a seal while tilling and is putting out a lot of oil. I hope it's easy, but I'm thinking bigger issues will be found.
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#10 OkieGt OFFLINE  

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Posted August 20, 2013 - 10:52 PM

I'm looking down the barrel on the engine on the Scrap Massey. She lost a seal while tilling and is putting out a lot of oil. I hope it's easy, but I'm thinking bigger issues will be found.

Only one way to find out,This is the fun part, learning about the part of the tractor one only sees once or twice in a lifetime


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#11 MFDAC ONLINE  

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Posted August 20, 2013 - 11:43 PM

My 1975 HH120 didn't need any valve work and the cylinder cleaned up to be on the higher end but still plenty useable without an overbore. I bought a standard overhaul set for about 50 bucks that included a new piston and rings. Broke in the rings tonite. I'm pretty confident the MF12 will outlive me once I get a new carb.

If I would have had to spend 2 or 3 hundred bucks, I probably would repower with as big of an HF engine as I could afford and try to rig a pully and an old school starter/ generator since I got 2 laying around. Not sure it would work but I would try!

Hope this works out where you can affordably rebuild the HH120.

Later---DAC
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#12 OkieGt OFFLINE  

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Posted August 21, 2013 - 12:09 AM

My 1975 HH120 didn't need any valve work and the cylinder cleaned up to be on the higher end but still plenty useable without an overbore. I bought a standard overhaul set for about 50 bucks that included a new piston and rings. Broke in the rings tonite. I'm pretty confident the MF12 will outlive me once I get a new carb.

If I would have had to spend 2 or 3 hundred bucks, I probably would repower with as big of an HF engine as I could afford and try to rig a pully and an old school starter/ generator since I got 2 laying around. Not sure it would work but I would try!

Hope this works out where you can affordably rebuild the HH120.

Later---DAC

Of course a harbor freight engine might take away some of the nostalgia of the machine and may not last as long as the orginal engine pulling the weight of a MF tractor. It could last several lifetimes because of how good they are, and of course you could buy another Harbor Freight engine, if for some freak reason the 150.00 lifetime engine gave out, lol.  I'm really not a fan of putting foreign made engines in tractors made by American Union workers, kind of like a insult .I understand repowering if you already have a new engine like Briggs Vanguard or a Kohler Command, but I wonder about the financial wisdom of spending upwards of 1800 on a new twin or 1000 on a new single as much as I wonder about that same financial ramification of a low cost engine. Sometimes you can be penny wise and pound foolish and visa-versa I dont see many 69 Camaros with Kia engines, wonder why? Seems like it happens to old GTs all the time. I have friends that always ask my advice, but in reality they only want me to tell them what they want to hear, we all do that to some degree, catching ourselves doing it may be akin to an epithany. Everyone must blaze their own trail and therefore end in a different Eunomia. Good Luck


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#13 HowardsMF155 OFFLINE  

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Posted August 21, 2013 - 02:02 AM

My 1975 HH120 didn't need any valve work and the cylinder cleaned up to be on the higher end but still plenty useable without an overbore. I bought a standard overhaul set for about 50 bucks that included a new piston and rings. Broke in the rings tonite. I'm pretty confident the MF12 will outlive me once I get a new carb.

 

Personally, I'm very leary of putting in a new piston and rings without overboring.  But, I haven't rebuilt a lot of engines either.  My first two Gravelys got rebored by someone who dealt with Gravely engines on a regular basis, with new pistons and rings.  That has been over 15 years ago, and both engines are still going strong.  

 

First, maybe Ben can tell me if that piston will work in my engine.  If not, I may try using a standard size piston to rebuild.


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#14 HowardsMF155 OFFLINE  

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Posted August 21, 2013 - 02:06 AM

Of course a harbor freight engine might take away some of the nostalgia of the machine and may not last as long as the orginal engine pulling the weight of a MF tractor. It could last several lifetimes because of how good they are, and of course you could buy another Harbor Freight engine, if for some freak reason the 150.00 lifetime engine gave out, lol.  I'm really not a fan of putting foreign made engines in tractors made by American Union workers, kind of like a insult .I understand repowering if you already have a new engine like Briggs Vanguard or a Kohler Command, but I wonder about the financial wisdom of spending upwards of 1800 on a new twin or 1000 on a new single as much as I wonder about that same financial ramification of a low cost engine. Sometimes you can be penny wise and pound foolish and visa-versa I dont see many 69 Camaros with Kia engines, wonder why? Seems like it happens to old GTs all the time. I have friends that always ask my advice, but in reality they only want me to tell them what they want to hear, we all do that to some degree, catching ourselves doing it may be akin to an epithany. Everyone must blaze their own trail and therefore end in a different Eunomia. Good Luck

Well, if I had one of the Vanguard 14 hp twins, I'd be trying to put that under the Massey's hood!!  But I don't, and I don't see any point in spending $1000 or more to get one.  BUT I also don't want to spend money doing an inferior rebuild and have issues in a few years.  I may end up with machines that see less use than others, but no deliberate trailer queens allowed in my shed!



#15 OkieGt OFFLINE  

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Posted August 21, 2013 - 07:03 AM

Personally, I'm very leary of putting in a new piston and rings without overboring.  But, I haven't rebuilt a lot of engines either.  My first two Gravelys got rebored by someone who dealt with Gravely engines on a regular basis, with new pistons and rings.  That has been over 15 years ago, and both engines are still going strong.  

 

First, maybe Ben can tell me if that piston will work in my engine.  If not, I may try using a standard size piston to rebuild.

I totally agree with you about reboring, IF they mic out within tolerances okay, but seriously is ANY 40 year old engine  going to mic out within tolerances, I doubt it. I could see it happening ONLY to a engine that wasn't used or run 75 percent of the time. I could see it more on a walk behind than a rider though, so It could happen, but so could misreading a micrometer, I do it, the guy at the shop can do it, were human. If the parts were more readily available it would be a no brainer as the boring is only about 75.00


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