hhm80

[paxson]

I have an HHM80 tecumseh, and I'm prob. going to have to do some work to it. I haven't got in it yet to find out what yet, but what I was wondering is... what performance type upgrades or modifications could I do to it to get a little extra power or a lot of extra power depending on cost? What will give me the most bang for my buck? It will be on a trike with 22x11-8 tires all the way around. The motor has a 12volt starter and headlight set up also. I think I have a couple mikuni carbs "somewhere" whats the biggest size I could run on this motor? I think I have a vm26 but not positive. I got a couple with a basket case Harley 45" motor. Do they sell an adapter to fit a mikuni to a tecumseh? I know a lot of questions, I'm just looking for some suggestions or tips. Thanks a lot , this site has been very informative.

 

[Gustavo]

Hello paxon
That's a nice engine you have there
As for performance the mikuni would be great you will probably have to fab up your own intake though but it will be well worth it
Also make sure to remove the governor
Alot of people vow by a billet rod but I personally have never had a thrown rod as long as you keep the wheels on the ground you should be ok if you want to make it an all out race motor turning major Rpms than a billet rod would be wise but that's When things start grttig expensive and as you said you want the most bang for the buck

 

[paxson]

Thanks for the info gustavo. I will try to find those mikuni carbs next week, I have all the 42 harley parts at a friends house. Does anyone else have any advice, comments, or tips. Can I put in different valves?? springs??? port?? polish?? mill the head?? etc. If so how much? or words of caution or warning on what not to do. I have never really messed with small engines at all, and not to many shops around that don't want $70.00/hr. for shop fees. I have about 6 weeks to plan and learn before I can actually get to work on it. Is there a place that sells tecumseh performance parts on internet?

 

[roccosbike]

Clements Racing Products, LLC

They sell stuff but it aint cheap

 

[The Restore Kid]

Do they build HYPO parts for the 8 horses? I am not sure you can get a billet rod for a Tec 8 horse... If you can do it without a doubt, but if not, I would leave it as it is and run it.. They make plenty of power but are not made for crazy RPM's and WILL explode.. :glare: Then you'll be crap out of luck.. :laugh:

 

[roccosbike]

The only info I found on the rod thing is a star racing rod but you have to have the journal ground down to fit the rod.

 

[The Restore Kid]

Just use your motor like it was intended to be used man.. :laugh: They are torque monsters anyways.. HELL of a shame to blow an engine like that up.. :chinese: Honda wanna be's are cheap and MADE to blow up.. We aren't running out of those any time soon.. That Tecumseh is a One Off and Done run... No more ever comin around again... The ship done sailed on those ones.... :sad:

 

[roccosbike]

DSCI0013a.JPG (image)

They are capable of making 40HP but it will cost ya

 

[paxson]

I thinking I may just rebuild back original, but with some NOS parts. I got a potential lead on some today. Guy retired about 18 years ago with some parts left in his garage.
I don't really want to chance blowing it up. All it has to haul around is myself(6';220lbs.) and my son(8yrs. and 90 lbs,) It has 3 22x11-8 tires and a comet 20 series converter w/ a differential axle.Comet has a 7 in. diam. driven . Does everyone think that will be enough power and torque to pull us around decently?

 

[The Restore Kid]

Yeah, thats pretty much how most of them were made.. :laugh: An 8 horse Tec with a TAV setup will pull a truck.. If they have billet rods that you can get for a good price, Then I'd say go for it... I wouldn't even attempt to run an 8 Horse Tec without an aftermarket rod beyond it's red line though...


Actually it's about everything that Peerless differential wants to do just the way the machine is. They have a tendency to blow up too when ya really give them hell.. 40 horse might be a bit much for it.. :doah:

 

[paxson]

On the original as possible thought, besides a billet rod, what else could I do to make this as reliable, dependable, and "bulletproof" as possible. Not necessarily fastser just stronger with some uumph. I truley know nothing of this type of motor. Also would a straight axle be better than a differential?


Rocco that is one tough looking motor. It looks like it would be fun, but I don't think I need anything like that just to run around my timber with. I'm healing up now with a couple plates in my neck. My wife would just go ahead and smother me when I fell asleep.

 

[The Restore Kid]

A strait axle would make a 3 wheeler really hard to turn.. They do have pretty strong differentials available from racing kart manufacturers.. If you had a Hypo rod, you could add a big cam and valve springs, port polish, mill the head or a thinner head gasket for compression.. That will bring the power and rpm's way up, and still be %100 stock looking.. The tecumseh fully adjustable carbs are very good running units so that with an un-governing, and a billet rod with big cam would realluy bring the thing to life...