Low End Loss

[stkcode]

Hi,

First post here...since others have probably already been their, done that. I'm looking at giving my kart a little boost in speed but I'm concerned about not having enough low end grunt to get going.

Current setup:
One wheel wonder (single drive wheel)
12T Max-Torque Centrifugal Clutch
72T Sprocket
#35 chain
11" Burris Slicks
3600 rpm gov'd 5hp briggs flathead

Website caluclator rates the theoretical top speed at 20 mph.

I'm looking at changing to a 15T centrifugal clutch and a 59T sprocket...which would put it at around 30 mph. Which is pretty much my top speed goal.

With a 5hp motor....how much bottom end will I loose? The motor is stock minus a 3-stage header, k&n type air filter, synthetic 10w-30 and open crankcase breather.

Right now I can spin the drive wheel from a dead stop with the current setup. I suspect with the change I wont be able to...which is fine with me...but I'm just trying to figure out if it I would have to get out and push to get it rolling.

I thought I'd ask those who have more experience then I do.

Thanks,
Jon

 

[freakboy]

You should be able to get her up and goin.

 

[Rickracer]

I would bump up the compression, advance the timing a little, maybe loosen up the clutch a little, and ditch the governor, stick with your 12t clutch, but drop to about a mid 60s rear. It should accelerate quicker and have a much higher top speed.

 

[stkcode]

Thanks for the advice. Unfortanetly, removing the gov is pretty much out. Other's use this kart...some seem to think a motor can rev to "blue sky". They just don't understand it has it limits.

I guess if I could put some kind of light that would go on at a certain rpm...like a shift light found on some tachs...it might be ok to remove the gov. It would have to be real simple...so any bozo knows that when the light comes on...they need to let off the gas some.

 

[Rickracer]

You could also adjust the governor to give you maybe 4500~5000 rpms.

 

[Kaptain Krunch]

Or you could just make a throttle stop, use something that can be removed easily so when you want to ride it you can take it off.

 

[Rickracer]

A throttle stop doesn't give you full power on take off, that's why they made governors to begin with,

 

[1992suburban]

a 12/60 works well..

If your concerned with the motor BLOWING from over revs.. I doubt it will if its STOCK with governor removed..

it prolly wont have enough power/potential to grenade itself.. I have a (clone) 6.5 that wont turn hard enough to BLOW and the gov. is OFF

with a 12/60 and 11" tire it goes 35-36 EASY I mean EASY

 

[stkcode]

Thanks for all the input.

I was considering adjusting the gov higher...but was wondering if the plastic gov gear or other gov pieces can handle the higher rpms? Since the motor is stock, I presume the valves will float any how without the gov.

I bought a 59t sprocket. I may also try a mid 60's sprocket as also suggested, if I can fine one inexpensive enough.

Thanks.

 

[Rickracer]

I'm pretty sure the governor will stay together @5000 rpms. Valve float is not a very good rpm limiter, #1, it kills valvesprings, #2, when the springs get weak enough, you drop a valve, BAD juju,

 

[Jdominique]

Remove gov - free
Stiffer valve springs - $10
Billet rod - $50

Rev to 6k and not worry about it. With the parts you have now, put that in the speed calculator revving to 6k.

 

[Rickracer]

, now we're talkin,

 

[hd4ou]

Remove gov - free
Stiffer valve springs - $10
Billet rod - $50

going faster-- priceless!!

sorry, couldn't help it...