Changing speed with sprockets?? Possible??

[Stonewall]

I'll do some tooth counting and figuring tomorrow. Maybe a combination of 2-4 fewer teeth, and some higher rev mods to the twin will get just what I want.

[Robinhood02]

I'll do some tooth counting and figuring tomorrow. Maybe a combination of 2-4 fewer teeth, and some higher rev mods to the twin will get just what I want.

Im guessing but my guess is youll have roughly 30 teeth , remove 4 teeth and it should give you about 29 mph WITH the bigger tires too, once i get the actuall count i can give you final numbers

[Stonewall]

29 mph sounds great, I just want to make it a little bit more practical for running around fields checking stuff, and more fun of course.

Jersey, I'd like to know more about the higher rev mods that you have done.

[Robinhood02]

Jersey, is there a way to adjust the governor to get say 500 more rpm ?

[jerseybigfoot]

Depending on the engine you are either moving springs or adjusting screws or bending the governor tangs (Briggs vanguard). you should also have a good tach. I have a good induction meter. Another solution is to remove the mechanical Governor and add a small engine rev limiter (they are pricy). Briggs and Kohler v twins have a restricted stock exhaust and can only over rev in neutral or screaming down a hill. There are plenty of engine manuals on line or for sale that describe the adjustment. There have been posts here describing the adjustment for quite a few engines already. I just did a search for governors and there was about 100 posts. lifold did a partial governor bypass that works well. I think he has photos of the mod.

[Robinhood02]

eh thanks alot there Jersey, i'll do some checking. i've always thought that they were governed too low, if you look up the power band of a 18 hp briggs you'll see the powerband is from 2200 rpm to about 4200 rpm , they cut off 65% of the potential horse power by governing it to max out at 2800 to 3200, you mentioned that it needs new springs ,do you know what rpm the valves start floating ?

[Stonewall]

Robinhood, I counted teeth on my sprockets this morning, and you were right, the driven do have 30 teeth. The t-20 sprockets have 15.

Jersey, I am using a Kohler CH25 on my machine, and will not be using the stock exhaust, just straight pipes.(with rain caps) Everything else will be stock. What tach do you recommend? Is the Sunpro tach that I can get at Autozone good enough?

[Robinhood02]

ok, drop 4 teeth and put on the larger tires and you should get 29.58 mph ( presuming your motor will maintain its original maximum rpm)
figure out how to adjust your governor 500 rpm more and you'll have aprox. 33.31 mph, (this also presumes your back will be able to take those speeds) being 16 well you can probably take it LOL (not these old bones)

[Stonewall]

(this also presumes your back will be able to take those speeds) being 16 well you can probably take it LOL (not these old bones)

LOL, that speed is mostly just for the gravel roads around here. Those tall sidewall Argo tires ought to help cushion it a little. 33 mph is right at where I want it, I'll do all those mods and see how it turns out.

[jerseybigfoot]

You want an inductive tach like an Equus 6068 It gets the signal off the plug wire. Briggs start to float their valves around 4500 rpm depending on the age of the engine. Some rev kits will have springs some will have shims for the existing springs. They will also have heavier alum push rods or some people replace the aluminum push rod with the steel push rod

[lewis]

The tach Jersey mentioned is a pretty good tach i have one on the Crush.

Equus+6068 - JEGS High Performance

[Robinhood02]

thats a nice tach and cheap too, i just ordered two , thanks for the link and info, more toys

[TURNEROFFROAD]

Back out of the ashes for a another look. I've been trying to research this topic in the hopes 30-35ish mph was possible with the Argos and still have Lo range for the nasty stuff. We run a lot of smooth gravel roads and such and could honestly benefit from the speed increase to cover the smooth ground.

But I sure wanted to retain low end for the slow tedious terrain. Will low range accommodate this? I'm not opposed to engine mods what so ever.


Thanks for the info in this thread

[Mike]

Back out of the ashes for a another look. I've been trying to research this topic in the hopes 30-35ish mph was possible with the Argos and still have Lo range for the nasty stuff. We run a lot of smooth gravel roads and such and could honestly benefit from the speed increase to cover the smooth ground.

But I sure wanted to retain low end for the slow tedious terrain. Will low range accommodate this? I'm not opposed to engine mods what so ever.


Thanks for the info in this thread

This thread mainly talks about engine modifications and I think that's where you should start. You would retain low end torque and gain the speed you are looking for. Going from a governed 3600 RPM to 5000RPM will increase your top speed 38%. So, if your top speed was 20, it would now be 28.