Small Engines (Lawn Mowers, etc.): Engine pulley switcharoo, power transmission components, diameter shaft

Question
I have a 1981 Toro Snowthrower 524, Model 38040.  I'm switching the 5HP (worn out) engine with a used 8HP (not as worn out).  Mounting brackets etc., switch over just fine...the only problem seems to be the size of the crankshaft.  The 5hp has about a 1" shaft, the 8hp has 3/4" shaft...I need the 2 slot engine pulley from the old 5hp...but the shaft on the 8hp will not accept it.  Can I find the same size pulley for the smaller shaft of the 8hp?  If so where?  Or should I try welding the pulley with the bigger diameter shaft hole onto the smaller diamer shaft, anticipating never using the 8HP engine for something other than the snowthrower?  I am stumped...please help.

Thank,  Jason

Answer
Hi Jason,

I would only weld the pulley to the shaft as a last resort.  Maybe you can bush it instead.  See: http://www.grainger.com/production/info/granger-supply.htm Click: Products > Motors & Power Transmission > Bushings > Steel Reducer Bushings. I found: Steel Reducer Bushing, Inside Diameter 3/4 Inch, OD 1 Inch, Length 1 1/4 Inches, Zinc Plated, With 3/16 Inch Open Slot for Keyway and Setscrew, Package.

Or check Grainger for a pulley under:  Motors & Power Transmission >  Components > Sheaves

Or: http://www.thomasregisterdirectory.com/hoists/sheaves_0041855_1.html

Good Luck and let me know how you make out.
Michael