# hh100 hh120 tecumseh



## RON BERG

DOES THE HH100 AND HH120 CRANKSHAFT AND ROD INTERCHANGEABLE


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## peachfuzz

Right up front, NO.

An HH100 has a 2.75" stroke. The HH120 is 2.875". 

Now, can you put an HH120 rod and crank in an HH100 block? Not sure, but since both engines also have different pistons, there may be an issue with the flyweights on the crank either smacking the piston at bottom dead center or the bore at top dead center. I know for a fact that the HH120 and HH100 blocks are entirely different as well, so whether or not you will have true center on the crankshaft is also an unknown (meaning if you put an HH120 crank in an HH100 block, will the piston rise out of the block at TDC?).

>pf<


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## guest2

Hi Ron
Welcome to TF!:cheers: 

I'm not sure but I'll try to find out. The rod may be different since there is a 2hp difference in these two engines so I think the bore and stroke would be different?


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## guest2

pf

As I was typing, I was thinking I know you could answer this!


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## RON BERG

*hh100--hh120*

gentlemen thank you very much now do you know where I can get a crankshaft and rod for hh120

iceberg


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## peachfuzz

Ron,
A couple of things:

Try calling the Tecumseh Tech Service hotline and talk to an engineer. Tell him everything you want to do, and they'll give you a yes or no on the HH100 / HH120 interchageability thing. They are very helpful and they will pull the prints and check to see if it is possible - I've dealt with them on several occasions and they've always steered me in the right direction.

Or, you can post the same message you posted here on the yahoo Tecumseh engines group site - there is a Tecumseh tech/sales guy on there that is VERY knowledgeable about all their products and he could also tell you if it is possible.

In terms of buying parts, I've gotten the best pricing from Outdoor Distributors in Alabama - if you have the part numbers go to this site and you will get pricing. 

http://www.outdoordistributors.com/

I have an HH120 built to spec 120173D and the PN for the crank is 33393A. The rod (standard) is 33093A. If you have a different spec, you will want to verify that the part numbers are the same - they should be - usually different specs reflect exterior aspects of the engine such as carburetor, gas tank mounting, bolt patterns, etc. Usually the base block is the same and the internals are the same. If you call Outdoor Distributors and give them your spec, they'll pull it up for you and if you ask them for the parts list they will send or fax it to you so you will A) have all the part numbers and B) can go online and price/order what you need. 

Finally, if you replace the crankshaft, ask what kind of teeth are on the crank gear - years ago they phased out the straight cut gears and went to helical - which then means if you have a straight cut cam shaft and a straight cut governor gear, you will have to replace them with helicals as well. A little 'surprise!' I got when I overhauled my HH100 in 2001...

If you have any more questions, let me know - hope it works out. Heads up, parts are expensive, but they'll last another lifetime if the engine is maintained.

>pf<


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## RON BERG

*hh100-hh120*

thanks pf


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