Vintage Tecumseh rebuild

[Rooks]

I'm looking to start ordering engine parts for a late 60's, 3.5HP Tecumseh engine that came stock on a Sears minibike. The model/sn plate on the blower case is long gone, but I do know that it is a 3.5HP. Can I just assume that it's a H35 model or that H35 model parts will be compatible? I'm not at all familiar with the differences between the early and late model Tecumseh 3.5hp engines so any advice will be greatly appreciated.

Here are a couple pictures of the engine...if that helps at all.

 

[ole4]

Looking at the ports is the exhaust on the left or right port? Can't tell from your picture. H series exhaust is on left HS series is on right.

 

[oldfatguy]

have you had it running yet ? If it runs good with out smoking you could just leave the internals alone and use it as it is. The part that wears on those engines is the crank and rod journal which will cause it to knock and then throw the rod. As complete as that engine looks it's probably still in perfect shape inside.

 

[Rooks]

The exhaust port is on the left (clutch) side...so that's good info to know. Thanks. The engine has been out of commission for about 32 years now. Snapped off the end of the connecting rod when I was 11 or 12 years old...shortly after figuring out how to override the govenor. At that time I took the side case off...pulled the connecting rod and piston out...saw there was no damage to the cylinder...put the parts in a box...pushed the bike into a corner of the garage....and that's where it's been sitting ever since. After a few moves and few garages later...I'm finally going to rebuild it.

Do you guys know if the different generations of the H35 use the same parts? I would think the connecting rod and piston would be the most critical as far as specs go for the parts list I come up with so far.

Piston and Pin Assy (Std)
Ring Set, Piston
Rod Assy, Connecting
Bolt, Connecting Rod
Nut, Connecting Rod Bolt
Element Breather
Housing, Blower
Clip, Shorting
Breather
Govenor Spring
Govenor Linkage
Oil Seal
Base Gasket
Carb Mounting Gasket
Carb to AirClnr Gasket
Exhaust Gasket
Intake Gasket
Head Gasket
Starter Recoil Assy
Carb Rebuild Kit
Float

 

[jrzmac]

I just checked this website I know, and every h35 engine I checked had the same model connecting rod. I started at H35-45000P, and worked my way down to H35-45542M. but H35-45613S on down to the newest ones they made had different rods. I think it's safe to say that your engine is old enough that you could use one of the old numbers, like H35-45000 to about H35-45442M. it's kinds tricky to work your way around this site, but if you want, I can pick a random engine from towrds the top of the list and send you the links for the parts you need. let me know?

 

[Rooks]

Thanks for the offer. I found a site as well that lists out all of the generations of the engine and noticed there are definitely changes between the 'alphabetic' revisions of the engine...more so than the 'numerical'. This mini was a hand-me-down from an uncle. I'm going to have to contact him to find out what year the bike was purchased to narrow down the possibilities. Hopefully I find that they ran an 'alphabetic' revision for a decent number of years...otherwise this rebuild might be a total trial and error PIA.

Any of you guys familiar with any shops out there that do vintage restores? Worse case scenario...I'm thinking that might be a decent way to expedite this project.

 

[Jeff Clark]

Thanks for the offer. I found a site as well that lists out all of the generations of the engine and noticed there are definitely changes between the 'alphabetic' revisions of the engine...more so than the 'numerical'. This mini was a hand-me-down from an uncle. I'm going to have to contact him to find out what year the bike was purchased to narrow down the possibilities. Hopefully I find that they ran an 'alphabetic' revision for a decent number of years...otherwise this rebuild might be a total trial and error PIA.

Any of you guys familiar with any shops out there that do vintage restores? Worse case scenario...I'm thinking that might be a decent way to expedite this project.

I can do it but shipping would be the killer.

 

[delray]

also you might want to think about saving that sears minibike sticker. maybe take the tank off and take it into somewhere that can remake a new sticker for you..............goodluck on your project:thumbsup:

 

[jreid50]

if you need any help let me know! I am finishing up another Tecumseh hh100 right now! If you go to the project logs, and look for HH100 rebuild that is the on I am finishing!