Tecumseh Manufacture date by style

M

mfire39

Member
#1
#1
Since this has been a question that comes up a lot lately, here is an ID guide that covers the 4 major differences in Tecumseh small frame flatheads over the years. This is by no means set in stone, and I encourage anyone who can add to this, please feel free to share any further info or photos. I’m a bit of a Tecumseh nut, so this is something that I just thought I would share.

Tecumseh small frame (2-5hp) Horizontal flathead engines, narrowing the MFG date ID by style of engine.

Late 60’s to early 70’s. Note the “Thin” blower housing.. These will usually have a riveted ID plate on the front flywheel side of the housing. Points & condenser ignition. HS40 & HS50 have the intake on the left side when viewed from the rear. H25, H30, and H35’s have the intake on the right side. Tank could be a side fill or center fill, and will also have a lower tank bracket.

http://i276.photobucket.com/albums/kk38/mrflash39/OldMiniBikes/ID%20plate_zpst9aqhavk.jpg
http://i276.photobucket.com/albums/kk38/mrflash39/OldMiniBikes/BVUEMQEWkKGrHqMOKkMEwP0Gl4kBMMtfDTw_12_zpst5f7uwvx.jpg
http://i276.photobucket.com/albums/kk38/mrflash39/OldMiniBikes/BVRG4wBWkKGrHqMOKkUEwQ72kckBMMdV4Gig_12_zpsqz0owsrp.jpg
http://i276.photobucket.com/albums/kk38/mrflash39/OldMiniBikes/BVGQzQBGkKGrHqEOKikEwOFKh2ZzBMM-tQl3jw_12_zpsag9za7nc.jpg


Mid 70’s to mid 80’s. Thicker blower housing, usually riveted or bolted on recoil. Engine ID numbers will usually be stamped in the top of the blower housing, alongside the top 3 head bolts. Tank could be a side fill or center fill, and will also have a lower tank bracket. Usually painted all one color which includes but is not limited to, white, metallic grey, red, or black. Adjustable carburetor.

http://i276.photobucket.com/albums/kk38/mrflash39/OldMiniBikes/IMG_6218_zpsk5ssus2p.jpg
http://i276.photobucket.com/albums/kk38/mrflash39/OldMiniBikes/IMG_6215_zps1tx0vpho.jpg
http://i276.photobucket.com/albums/kk38/mrflash39/OldMiniBikes/IMG_6219_zpsjzkwzipt.jpg
http://i276.photobucket.com/albums/kk38/mrflash39/OldMiniBikes/IMG_6220_zps85omglpk.jpg


Late 80’s to early 90’s.. Same thick blower housing, but the recoil is held on by 2-3 sheet metal type hex screws, with a plastic cap in the center of the recoil. They will have stamped ID numbers on top of the blower housing, which turned into a decal after 1993. These will usually also have adjustable carburetors, with solid state ignition. Tanks were either a side fill or center fill with textured plastic tops, and the late 80’s models will also have a lower tank bracket. Usually painted all one color which includes but is not limited to, white, metallic grey, red, or black.

http://i276.photobucket.com/albums/kk38/mrflash39/OldMiniBikes/HS40%20FB%204_zpsvq3pyitp.jpg
http://i276.photobucket.com/albums/kk38/mrflash39/OldMiniBikes/HS40%20FB_zpsjxanhtyr.jpg
http://i276.photobucket.com/albums/kk38/mrflash39/OldMiniBikes/HS40%20FB%206_zpsexph9mkr.jpg
http://i276.photobucket.com/albums/kk38/mrflash39/OldMiniBikes/HS40%20FB%202_zpsltbom5fk.jpg


Mid 90’s till the end of Tecumseh production, which was about 2007 for the flatheads. The blocks were not painted, and were usually left bare aluminum. Only the blower housings, air filter covers, and tank brackets were painted, and usually all black. They typically had non-adjustable carburetors, with a fixed main jet & closed circuit crankcase breathers that terminated to the air filter. They did not have stamped blower housings, but instead had a sticker label on the lower side of the blower housing by the throttle assembly. They had the the recoil also held on by 2-3 sheet metal type hex screws, usally with a Tecumseh HP rating sticker in the center of the recoil. Tanks were usually all a center fill, with no lower tank bracket.

http://i276.photobucket.com/albums/kk38/mrflash39/OldMiniBikes/Newer%20HS40%205_zpsgon0vvfc.jpg
http://i276.photobucket.com/albums/kk38/mrflash39/OldMiniBikes/H40%202_zpsnwbp8exv.jpg
http://i276.photobucket.com/albums/kk38/mrflash39/OldMiniBikes/H40%205_zps9avwrzay.jpg
http://i276.photobucket.com/albums/kk38/mrflash39/OldMiniBikes/H40_zpsfmlvfrcx.jpg
 
markus

markus

Well-Known Member
#12
#12
manchester1 said:
Good stuff. I would love to see how the different decals went with the years. For instance, the balloon and flag.:thumbsup:
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Tecumseh used the ballon until 1976 but in 1970/71 they came out with the flags which was put on and used specifically for recreational engines (minibikes, karts, trikes, etc...), So if it does not have flags on it in those years it was most likely originally indended for a mini! It appears that they nixed the use of flags around '76 as well. At that point they used the rectangular indian head design for the next few years, which went on most everything, recreational too.

some other things to note, the HS50 was introduced in the 71/72 range, and was always the mid 70's "square" topped shroud. since that shroud had no place for the rivet on id tag, they installed a small tag that bolted to a sidecover bolt, basically like the tag that came with a tec longblock replacement engine. They are really hard to find, does not seem like the mini bike companies were utilizing them, and I dont they were used too much on equipment either for the first year or so, probably till they were more "proven". Seemed to be game on by about '75 though for snowblowers etc.. 10lbs lighter than an H50 and a whole lot smaller!





I'm still trying to figure out when the HS40 was introduced, seems like around the 1968 timeframe.

I'll work on posting up some of the slight differences in the 74-down popular small frame engines that were most popularly used on the vintage bikes when I get a chance.
 
H

Havasu Dave

Moderator
#13
#13
markus said:
I'm still trying to figure out when the HS40 was introduced, seems like around the 1968 timeframe.

I'll work on posting up some of the slight differences in the 74-down popular small frame engines that were most popularly used on the vintage bikes when I get a chance.
Click to expand...
Interesting. My Powell came with what I assumed was the original lighted HS40. It has the standard shroud tag, HS40 55277B Serial Number 9330. It also had a tin tag affixed to the oil breather bolt that read SBH-200B on top, and 0127 12086 on the bottom. It came with the balloon decal, as did all of the Tec Powells at that time.
 
markus

markus

Well-Known Member
#14
#14
Havasu Dave said:
Interesting. My Powell came with what I assumed was the original lighted HS40. It has the standard shroud tag, HS40 55277B Serial Number 9330. It also had a tin tag affixed to the oil breather bolt that read SBH-200B on top, and 0127 12086 on the bottom. It came with the balloon decal, as did all of the Tec Powells at that time.
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sounds like it possibly has a replacement block with that extra tag. Short block Horizontal (SBH) Maybe :shrug: One of the blackwidows I had came with a replacement longblock on it. I don't know when the longblock was replaced, but the block had drilled holes for a starter like how they started to show up in the square shroud era and all the internals, while the same specs (longcrank/ball bearing) were of newer castings than all my other Rupp engines. You can see the tag there on it in this pic (I will have to dig around to see if I saved that tag to see what numbers are on it)

 
H

Havasu Dave

Moderator
#15
#15
markus said:
You can see the tag there on it in this pic (I will have to dig around to see if I saved that tag to see what numbers are on it)
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The tag on mine looks exactly like that. Just mounted on the breather. Maybe Powell purchased a lot of Tecumseh replacement engines when they switched from Briggs, but got them with the shrouds and lighting coils. Interesting stuff.
 
capguncowboy

capguncowboy

Well-Known Member
#17
#17
markus said:
sounds like it possibly has a replacement block with that extra tag. Short block Horizontal (SBH) Maybe :shrug: One of the blackwidows I had came with a replacement longblock on it. I don't know when the longblock was replaced, but the block had drilled holes for a starter like how they started to show up in the square shroud era and all the internals, while the same specs (longcrank/ball bearing) were of newer castings than all my other Rupp engines. You can see the tag there on it in this pic (I will have to dig around to see if I saved that tag to see what numbers are on it)

Click to expand...

I picked up a Gilson a few months back and just got around to taking a close look at this past weekend. It has what appears to be the original lighted H50, but it has a tag on the block like that. Best I can tell, it reads "SBH 656" and "6160F".



 
Biffmini

Biffmini

Well-Known Member
#18
#18
The tag That starts w/SB stands for short block and is a replacement. Here's a pic of 1973 engine tag that's not a SB replacement
 No #'s on shroud
capguncowboy said:
I picked up a Gilson a few months back and just got around to taking a close look at this past weekend. It has what appears to be the original lighted H50, but it has a tag on the block like that. Best I can tell, it reads "SBH 656" and "6160F".



Click to expand...
 
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