what is it? Minibike Tecumseh mystery motor

[CarPlayLB]

I got this engine in a deal that included a Ruttman Wild Goose. This was the engine that was on the Ruttman. It has the minibike throttle, but no where on the motor is a serial number or designation. How can I tell if it is an H30/H35/Hs40? There are no rivet holes for a tag, and there are no stampings on top of the shroud...please help me!

 

[sludgeboy]

HS40. The intake is on the left. The intake doesn't not look like it has a square corner on the bottom right.

 

[CarPlayLB]

Hs40 should have either an id plate or a stamped number though. Was this some sort of "private label" deal?

 

[manchester1]

I bet that was the original engine:thumbsup:

 

[Oyster Bay Man]

The id would be on the side didnt post a pic of. Did u look on the side by the gas tank?

I found two gas tanks in that color last weekend. Never saw the color before.

 

[markus]

Are there threads in the exhaust port for a 1/2 pipe to thread in? hard to tell in the pics.

 

[delray]

looks to be a 4hp and i also notes it has id sticker under that blue paint and for the year it would be right around 74 or 75, if it is all original. two things that give it away are the old style oil fill plugs and the second design minibike throttle linkage. only those years i have seen that factory setups.......:thumbsup:

 

[sludgeboy]

Hs40 should have either an id plate or a stamped number though. Was this some sort of "private label" deal?

Not really. I have a white shroud with a Tecumseh sticker on it but no stamped numbers or ID tag. Really weird.

 

[delray]

also could of came with a small ID tag, held by one screw mounted on the side of the engine or oil breather screw. i am thinking whatever it had? somebody took it off when they painted blue......:doah:

 

[delray]

manchester1

I bet that was the original engine

good chance it could of been a ruttman engine. they did use center filled style gas tanks and the bikes where made in 74-75.

 

[roccosbike]

Are there threads in the exhaust port for a 1/2 pipe to thread in? hard to tell in the pics.

Like markus said if there are threads in the exhaust port its an HS40 if not its an HS50.

 

[CarPlayLB]

Thanks for all the replies. I believe it is threaded exhaust, so Hs40 it is. I was going to put a Briggs 5HP on my Ruttman, but I might use this one now...keep it close to correct
I appreciate all the help

 

[Oyster Bay Man]

manchester1
good chance it could of been a ruttman engine. they did use center filled style gas tanks and the bikes where made in 74-75.

That's good to know. I bet those tanks I found are Ruttman. Never saw that color blue on an engine that would match them until now. I'm going back to pick them up saturday.

 

[CarPlayLB]

HS40. The intake is on the left. The intake doesn't not look like it has a square corner on the bottom right.

The intake does have a square corner, bottom right...now what?
The exhaust is threaded, 3/4 NPT like 5HP Briggs

 

[roccosbike]

The intake does have a square corner, bottom right...now what?
The exhaust is threaded, 3/4 NPT like 5HP Briggs

Threaded 3/4 NPT? That's rare, probably an Hs50 motor if it has that intake though. Its hard to tell what size motor it is unless its in my position, then I can look at things and confirm. the bore is bigger on an Hs50 too.

 

[CarPlayLB]

Rocco,
I may just pull the head and measure...by chance you know the bore size for 40 and 50?

 

[roccosbike]

Rocco,
I may just pull the head and measure...by chance you know the bore size for 40 and 50?

Hs40 is 2-5/8" and the Hs50 is 2-13/16" for the bore, they both share the same stroke so they both use the same crank and connecting rod.

 

[CarPlayLB]

Thanks Rocco...appreciate your help!

 

[Stangrcr1]

And if you decide not to use that fine motor, I have a Cat that would like it. It might even purr. :laugh:

 

[delray]

none of this really surprises me. one of them weird......ut: tecumseh's. square corner would have to make it a 5hp....:shrug: like i said earlyer.
older style oil plugs with the newer second design throttle linkage.......ut: