Crank shaft length

#1
I am building a small Trike for the kids in our trike association and want to use a new Tecumseh 6 1/2 HP Power sport engine with Electric Start there is one on ebay model # OH195EP 71804C .
Question is it has a ball bearing in the PTO side but has a short 2 1/4 inch #/4 inch shaft . I will be using a Comet 40 series driver clutch and a 7 inch driven half.
Asking opinions on this length of shaft is it too short ? The seller says the Yerf Dog uses a engine with a 3 inch long shaft ( Does size matter LOL ) any advise would be great. Steve :scooter:
 
#2
Whether size matters is kind of like "how many licks does it take to get to the middle of a Tootsie Pop?" The world may never know.:confused: You should be fine with that crank. If anything, you may need to make a 3/4 (keyed??) slug as a filler, and use a retaining bolt through it and into the end of the crank about an inch or so. All of the torque will be in towards the block on the solid part of the crank.
 
#3
I was thinking along the same lines with a filler shaft, and the benefit of the ball bearing on the PTO side . I think I can find a sacrificial bad crank shaft to cut off and use as a filller and a long one piece key .
Thanks for the reply Steve
 
#5
I'll bet you won't have any problems using this engine...

Most clutches are only 2.25" wide, and don't need shafts longer than that...

Additionally, most clutches are not keyed through the entire length of the bore, usually allowing a 3/8" length at the end of the output shaft where an unkeyed spacer can be used...

I have made several crankshaft extensions, for both myself and for others, and there has never been any problems experienced if the crank is somewhere over 1.5" to begin with...

The crank extension can be made of nearly any material...it's not driving the clutch, merely keeping it aligned with the rest of the crank, and retaining the clutch if a flange is turned onto the extension...
 
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