In 1997 Tecumseh states in their product catalog that the HS40 is "discontinued production" (except if there's a larger order for that motor.) And in 1998 they release the H40 engine. My question is why? The H40 is really just an H35... why label an H35 as four horse power and call it H40? Below are the bore/stroke dimensions...
HS40 (1968-1997) = 2.625" x 1.938" (or 2 5/8" x 1 15/16") 172cc
H40 (released in 1998) = 2.500" x 1.938" (or 2 1/2" x 1 27/32") 156cc
H35 (1987 and later) = 2.500" x 1.938" (or 2 1/2" x 1 15/16") 156cc
I ask because i picked up a year 2000 tecumseh H40 with ball bearing side cover. And when i pulled the head (to check the bore), i was surprised at the small dimension of the bore. It sure didn't look like 2 5/8" diameter, and upon measuring it was not. It was 2.5" diameter... Thanks!
HS40 (1968-1997) = 2.625" x 1.938" (or 2 5/8" x 1 15/16") 172cc
H40 (released in 1998) = 2.500" x 1.938" (or 2 1/2" x 1 27/32") 156cc
H35 (1987 and later) = 2.500" x 1.938" (or 2 1/2" x 1 15/16") 156cc
I ask because i picked up a year 2000 tecumseh H40 with ball bearing side cover. And when i pulled the head (to check the bore), i was surprised at the small dimension of the bore. It sure didn't look like 2 5/8" diameter, and upon measuring it was not. It was 2.5" diameter... Thanks!
