Any tricks to making your mower a lil more peppy?

[JoeNoble]

The engine is a B&S 28N707 and I was just curious if porting and polishing the intake and maybe opening up the exhaust will give me a lil more power. Don't ask why I want my mower to be a lil faster cuz I don't really have an answer but I suspect it has somethin to do with the fact thy I can't afford to fix/build either of my Rx-7s lol.

 

[sparks325]

Joe,
I'll preface my reply with I'm not an engineer but here is what I did last summer when the grass was growing faster than we could cut it here in Ohio.
I noticed that (by the way my wife prefers to cut the lawn go figure) the mower would get behind the "power curve" Once it was into the heavy growth and by the time the governor would ask for more fuel, it was too late and the loss of RPMs continued until stall. My initial thoughts were not to let the slow down begin. Disconnecting the governor and installing a manual speed lever allowed me to control the engine speed. Although the speed was high the inertia wasn't there. No flywheel action. The blade was comparatively light. Here is where I decided to attach another blade 90 degrees to the original. Now I had twice the inertia and lots of speed. It was rather exciting when first spinning her up. Sounded like something between a V twin motorcycle and a helicopter.
The cutting action was good. I knew that the strain on the motor was a bit much. Using 60 weight motorcycle oil to ease the stress she seemed to be somewhat happy. Not a happy ending to the story though. Blew a ring this past weekend. Now looking for something engineered (i.e. buying a new mower) with much more power. I thought of going with another but larger engine. But I don't need another project right now, just a better mower..........
Brian

 

[Grass ala Mowed]

I ran nitromethane in one once (Yes, the "nitro" of top fuel dragsters). Only ran 5 minutes before the exhaust valve "tuliped", but I probably had double the horsepower. Seriously, I'm not sure how much porting and polishing would help on an engine governed to 3000-3600 rpm.

 

[sparks325]

Nitro...Sweet!:thumbsup:

 

[Mwh0428]

i heard that the little divets actually help with fuel milage and power. the reasoning is the divets cause tubulance which makes an "air barrier", but basically the air fills the divets and makes a ring around the inside of the intake ports which makes the air move through easier in you make it smooth then the air will not travel as good.

 

[benski]

Joe,
I'll preface my reply with I'm not an engineer but here is what I did last summer when the grass was growing faster than we could cut it here in Ohio.
I noticed that (by the way my wife prefers to cut the lawn go figure) the mower would get behind the "power curve" Once it was into the heavy growth and by the time the governor would ask for more fuel, it was too late and the loss of RPMs continued until stall. My initial thoughts were not to let the slow down begin. Disconnecting the governor and installing a manual speed lever allowed me to control the engine speed. Although the speed was high the inertia wasn't there. No flywheel action. The blade was comparatively light. Here is where I decided to attach another blade 90 degrees to the original. Now I had twice the inertia and lots of speed. It was rather exciting when first spinning her up. Sounded like something between a V twin motorcycle and a helicopter.
The cutting action was good. I knew that the strain on the motor was a bit much. Using 60 weight motorcycle oil to ease the stress she seemed to be somewhat happy. Not a happy ending to the story though. Blew a ring this past weekend. Now looking for something engineered (i.e. buying a new mower) with much more power. I thought of going with another but larger engine. But I don't need another project right now, just a better mower..........
Brian

Yep, MORE POWER:thumbsup::wink::biggrin: