Making a little more power

[DBXFX]

Hi guys. I'm currently in the process of making a sort of minibike/ dirtbike.

I have a 7hp (i think) single engine out of an old (maybe 80s) craftsman snowblower. my friend tells me that craftsman used to use briggs motors and it does look a lot like one... red paint, same valve setup as the 5hp...etc. athough it does have a tecumseh starter so im not sure.

anyways, i have the thing stripped down to the block (other than the flywheel which is being a PIA to get off) and im trying to think of ways to make some more power.

my first idea is to adjust the governor. is it possible to make the engine rev higher by shaving a little material off the weights of the governor gear? wouldnt less weight mean less centrifugal force and in return it would mean that the gov. would allow a higher rpm? i dont want to remove the gov. because my idiot friends will porbably just pin the motor till it blows.
ideas?

also, is it possible to gain power from advancing the timing in the motor. like if i were to align the cam one notch more on the crank? or will that fck stuff up?


really im just bored and trying to find some cool things to try out.

let me knwo if any of this makes sense. thanks

[Rickracer]

You can advance the timing by moving the flywheel in relation to the crank, 4° to 6° generally gives a nice bump in power. More compression adds power across the board, from idle to WOT. Porting generally helps top end, but if done efficiently and conservatively, can help low end as well. :cool:

[Russ2251]

Do you have the Craftsman part number from snowblower or engine? Should be located on flywheel/recoil housing.
Should be something like 500.xxxxxxx or 143.xxxxxxx.
Will help to positively help to identify power plant.
Chances are it is a Tecumseh.

[DBXFX]

I found the engine model. It took me a little bit of searching because its over 20 years old but this is what i found:

the snow blower is a sears made by Murray model 536906001. It has a 7hp L-head tecumseh engine 143.666382, aka H70-130205D supposedly.

so if i go ahead and manage to pull off the flywheel, will anythin fall off that i shoul worry about? does the magneto/sppark plug stuff attach to the block of the flywheel?

[anderkart]

So you got yourself a Tecumseh H70 there. Your magneto is attached to the engine. The flywheel just has the magnet, nothing falls off when the flywheel is removed.

[DBXFX]

anyone have any comments on my governor idea? will it work?

[Rickracer]

I would try swapping springs to one that's the same length but a little smaller wire diameter. That way, you can always go back to stock if need be. If you start hacking on the weights, it's an irrevocable mod. ;)