Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

Hi Guys,

I wanted to get some opinions on a repower idea that I've been toying with.  I have an MTD/Yard Machines 5hp/22" 2 stage snowblower that is about 6 years old.  Several times in the past few years I've thought that it was a bit underpowered.  The past snowstorm we had in Central PA (4" of snow followed by probably an inch or more of rain - causing a very heavy slushy mess) was my tipping point.   I am looking at replacing the 5HP Tecumseh HSSK engine with something in the 7-10 HP range.  Has anybody done this sort of swap before?  I am assuming I may need a few new pulleys and different length belts - but I am not anticipating more modifications than that.   Am I nuts?   Should I just sell the machine and pick up a used 8hp machine?   What are your thoughts?

Thanks

Eric

I put an 11HP B&S engine on a 10.5HP Tecumseh machine.

The chassis was punched for both sets of mounting holes.

I had to get new pulleys sisnce the 10.5 had a 3/4" shaft while the 11HP had a 1" shaft.

It works fine and I think I have more power. It could be due to new vs old engine, OHV vs "L-Head", 11HP vs 10.5HP or just wishfull thining on my part.

Two things concern me:

1. My change was relatively small. Yours looks like doubling the power and the parts on the machine may not be able to handle the extra stress; and
2. You might not see a big change, you have more power but the parts aren't turning any faster so they won't slow down as easily but the snow won't be fed from the augers to the impeller any faster nor would the impeller throw the snow much further ( on a good day). If you change the size of the pulleys and run the machine faster then things will wear out faster but the snow will fly further.

Good luck

         ITS NOT THAT EASY  ECSPECIALLY GOING FROM A 5 TO AND 8.   #1    YOU WILL NEED NEW PULLEYS  THATS A GIVEN.  YOU WILL BE GOING FROM A 3/4 DIAMETER CRANKSHAFT TO A 1".  YOU MAY NOT HAVE AVAILABLE THE SAME SIZE CURCUMFERENCE PULLEY GOING TO A 1" CRANKSHAFT.  THE PULLEY WILL ALSO HAVE TO ACCEPT THE SAME SIZE BELT THAT IS STILL ON MACHINE. IF YOU NEED TO GO TO A BIGGER PULLEY THAT CHANGES RATIOS. YOU WILL NEED TO REPLACE BELT LENGTH.   

Is the change over from 3/4" to 1" now at 8HP? My old 10.5HP tecumseh was a 3/4" shaft while the new 11HP B&S Intek was a 1". I was told at the time that the cutover point was 11HP.

I was able to order aftermarket pulleys that were the close to the same size. Adjustment of the idler pulleys took care of the rest. If I remember correctly the pulley for the auger was 1/2" larger. The snow does fly further but I have a hunch its the better torque from the OHV rather than the faster auger speed.


I'd be real careful that I didn't really overpower the machine, going from 5 to 6 or 7 HP might be OK but I suspect that 10HP would tear the thing apart.

Thanks for the replies so far.  I'm still debating what the smartest move is.  Problem I have with actually trading up to a more powerful machine is that they are all wider than the 22" width I have - and they won't fit well in my relatively small garage!   

From what I have seen on the engine websites - all the Tecumseh L-head engines (5hp -195cc, 8hp- 318cc and 10hp- 358cc) are available with stepped pulleys for an MTD application.  At least that's what I think they are telling me. 

Anyhow - thanks again for the replies and I'll let you know if I get brave and try this!

Eric

Find a new one now (good time for low prices), then sell the old MTD in the fall