Member
Join Date: Aug 2006
Posts: 68
OH
05-26-15, 03:32 PM
#1
Swapping rototiller engine with push mower engine
Anyone ever done it? The original engine, B & S is on its last leg, only 4 hp. Is it possible to swap it with say another 4 hp engine off of a lawnmower? I already noticed one problem. The mounting holes are 4 on the current tiller engine, where as most push mower engines are 3 hole designs. Do they basically all run the same RPM? Don't want to over do RPM's to the tiller part. Shaft length is another thing I'm not sure of. I should be ok with the shaft diameter, I think. Just need to take the pulley off the old engine.
Any thoughts? Thanks
Any thoughts? Thanks
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Group Moderator
Join Date: Mar 2003
Posts: 16,683
NC
05-26-15, 05:05 PM
#2
Without knowing the details of the engine your removing and of the new engine it's all just guessing but it seems you see some of the pitfalls; mounting bolt pattern, shaft length, shaft diameter, rotation direction... But anything is possible. How hard or easy it will be depends on how well you do your research and pick the right replacement engine. Then you need to consider all the work and possible risk of swapping engines versus reparing/overhauling your current engine. Almost anything can be fixed.
Member
Join Date: Feb 2014
Posts: 379
TX
05-26-15, 05:29 PM
#3
Most mower engines rely on blade for flywheel effect while the non mower engine applications need a heavier flywheel to maintain correct engine operation.
Try running mower engine without blade and observe difference.
RR
Try running mower engine without blade and observe difference.
RR
Forum Topic Moderator
Join Date: Jul 2001
Posts: 16,567
GA
05-26-15, 06:14 PM
#5
All the points of consideration have been brought up. As mentioned by Rooster: You will need to be able to swap the flywheel from one to the other so you can have the cast iron flywheel instead of the aluminum one used on the push mower. Don't try to crank the one with the aluminum flywheel or you may hurt yourself (unless it still has the blade on it). If the flywheels aren't the same, it's not going to work.
"Who is John Galt?" - Ayn Rand (Atlas Shrugged)
God bless!
Member
Join Date: Aug 2006
Posts: 68
OH
05-27-15, 05:14 AM
#6
Good point about the flywheel, as I know what it's like pulling the cord with "no load" on it.. Easy to rip a rotator cuff.
So the thinking is, swapping flywheels as well? Guess I never realized that different metals were used in flywheels. I assume the magneto/flywheel would have to stay together as well. Which could also mean a spark plug change.
This maybe a bit more than I want to undertake. It would be easier to just find a compatible engine, if the B & S I currently have wasn't so old. Only bright spot is the current engine is a horizontal shaft, (as are most push mower engines.)
-Thanks all for the advice.
So the thinking is, swapping flywheels as well? Guess I never realized that different metals were used in flywheels. I assume the magneto/flywheel would have to stay together as well. Which could also mean a spark plug change.
This maybe a bit more than I want to undertake. It would be easier to just find a compatible engine, if the B & S I currently have wasn't so old. Only bright spot is the current engine is a horizontal shaft, (as are most push mower engines.)
-Thanks all for the advice.
