race mower

S

sss

Active Member
hi there i have a 7hp 3 speed rear engine rider and want to take it racing but do not want to spend big money on new gears etc and do not want to remove the govener what else can be done too make it faster the decks already off.
 
sss said:
hi there i have a 7hp 3 speed rear engine rider and want to take it racing but do not want to spend big money on new gears etc and do not want to remove the govener what else can be done too make it faster the decks already off.
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If you don't want to change the gearing or remove the governor the only thing I can think of is to change your drive pulleys. This would have to be something to experiment with. You would want some acceleration plus top speed.
 
When I was a teenager in the 80's some friends and I took an old dynamark(I Think) with a briggs engine, took the rotted out mower deck off and changed the pulleys on the transmission drive and put a real tiny one on and proceeded to race it right down the road at full spead only to flip it over in the ditch because you have no steering at high speed only to have a crash and burn scenerio.
 
The formula for getting more speed and power out of just about any internal combustion engine is the same; make it turn faster, move more air and fuel. Larger valves, higher profile cams, larger carburetors, better ignition systems, scavenging exhaust systems, etc. are all part of the equation. For on the cheap, changing pulley sizes on the engine and transmission (assuming it's belt driven) and adding some toe-in to the steering geometry are about all you can do.
 
What do you mean by "racing"? Do you mean real, sanctioned racing, or just booting it down the back roads, hoping you don't run afoul of the law? If the former, you really should ask in a lawnmower racing forum. Google is your friend.
 
the mower is a chin drive by racing i mean racing it againsed freinds who also have a mower for racing. i dont remove the govener because i thought it was there to protect the engine from damage.
 
The governor is there for long hours of mowing and that is what the engine was designed to work at. I know some people that use lawn mower engines for go cart racing and the first thing they do is remove the governor. They can get about two seasons of racing out of a engine. They are racing about once week. Raceing isn't cheap. but what you are doing sure sounds like fun.
enjoy
 
I live in Utah and help with our local chapter racing. There is a way to race your mower with out removing the govener. You can race in Stock class where you only take the blades off the deck and race it, (we have three mowers set up for this, one of them I use on a weekly basis to cut the lawn).

The other choice is to run in the performance classes, you don't have to remove the govener but you can over ride it with a hand throttle, routed down to the govener and attach it to a govener spring off a 5hp briggs directly to the govener arm where the throttle linkage conects and it will bring the engine up to about 4000 rpm. Be sure to leave your stock throttle hooked up.

You can go to The United States Lawn Mower Racing Association and download the USLMRA rule book and it will help you decide what to do with it.

You are correct in that the govener is there to protect the engine but it is there to protect you as well. Any speed over 4000 rpm you should use a scatter shield or a billet flywheel.
 
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