Slow throttle response @ start of race!?

Harvey Williams · Joined: 07 Feb 2004 Posts: 14

I race easykart heavy 125.
This weekend in the PanAmerican Easykart Race @ my home track in Homestead, FL (Great Race!) my kart wasnt fast from the rolling start @ the drop of the green flag. When i nailed the throttle my kart didn't accelerate like the others.
Other than the obvious possibility of runng to rich (i closed low speed jet down about 1/8th for the feature race start - no change in throttle response). The motor didn't feel to have the punch i have become acustomed to.
The track did change the mandated rear sproket from 81 to 79.

1) Does that small of a change in gearing take the low end punch out of the motor?

2)Are there any other things (maintenence, chasis set up, carb tunning, etc.) to consider or look at for improved acceleration @ starts?

PS: we are not allowed to adjust carberator setting while racing on the track.

Patrick Hubbell · Posted: Mon Apr 05, 2004 10:35 pm Post subject:

What is the pipe length? the flex pipe between the header and pipe should be at least 2-1/2". Gearing should put max rpm's at 15,500 to 15,900. low speed needle 1-1/4 high 7/8 for sprint track. Check the reeds for broken pieces.
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Patrick Hubbell

Harvey Williams · Joined: 07 Feb 2004 Posts: 14

Patrick
After the start once the motor cleared out it ran fine.
In easykart, everyone has to run the same gear ratio.
the easykart carb set up has a low speed needle that when closed is still @ 1-1/2 turns out (supposed to keep the motor from running to lean) and the high speed is jetted.
Ill take a look at the flex and the reeds.
All other factors being equal would one brand/heat range spark plug be less prone to load up at low rpm versus a differnt plug?

Paul Crozier · Posted: Wed Apr 14, 2004 9:59 am Post subject: Poor throttle response

I am still having the same problem with my Parilla Leopard, i rebuilt the carb with new gaskets/diaphram and i also checked the reeds for cracks.

I raced last weekend and i still had the same problem and now I am wondering how should the engine idle, what rpm should it idle at while it is warmed up ? How does the idle effect the carb settings ?.

regards,

Paul Confused

joseph hollinger · Posted: Wed Apr 14, 2004 1:37 pm Post subject: Re: Poor throttle response

Paul Crozier · Posted: Sat Apr 17, 2004 9:35 am Post subject: slow throttle response

should the engine idle on its own once it is warmed up ?

joseph hollinger · Posted: Sat Apr 17, 2004 9:43 am Post subject: Re: slow throttle response

Marty Troup · Joined: 03 Jan 2003 Posts: 197 Location: Canada, Monteral,

Paul mine will idle just fine try opening your low speed needle a 1/4 turn and see if it helps as you should get some idle from it and I would guess that it idles just fine when cold but when hot it is not so good and thats fine but if you have the low needle too lean you can stick your motor when you let off from high rpm!!

Mitchell Dixon · Joined: 17 Jul 2003 Posts: 330

Harvey,
at the start, "hop-out" of the seat and u will get a little push from the lessened weight...if you watch alfredo and dairo do it u will notice a little jump in the karts speed...my father has also seen this and told me its effect...which i did not think was even evident...alos on the start, stay on the bumper of the kart in front of u and when you come around the back turn give it soem gas and then punch it when u hear or see every1 else do it. that will give a little better start because the engine wont b as flooded sometimes or gove it more gas in a lean condition. but jus make sure you brake or let off before u pass tony at the start so u dont push any1 into an accident...HOPE THIS ALL HELPS.
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"I am not afraid, I was born to do this."

-Joan of Arc

Harvey Williams · Joined: 07 Feb 2004 Posts: 14

Mitch,
Thanks for the pointers on the start.
Ill be hopping at the next start, lets see what happens.
Didn't see you @ the panamerican race, how come?
Do you run the low speed any leaner for the race starts?
I was running about 1/2 turn out. I just recently set the low speed just past 1/4 turn out. Seems to run a bit stronger.

joseph hollinger · Posted: Wed Apr 21, 2004 8:00 am Post subject:

Mitchell Dixon · Joined: 17 Jul 2003 Posts: 330

harvey...last weekend at my race i noticed that at the start i was slow n went fine after i got up to speed....but my engine stuck and when we went to exchange the motor i noticed the clutch was almost fully worn down! that could be one of your problems or you may just be flooding the engine more than others. The low speed setting i run is used through out the race, i dont worry about adjusting it(less things to mess up on...lol). Depending on the jetting you run, dont run to lean....the most i will go down is 1/4 torns open on a "normal day"...I have been told that 1/2 turns open is good for running quick.

Sadly I wasnt available for the Pan-Am race...which i wanted to do, but my parents took me on a family vacation one last time b4 i went off to college.

But i heard it was one to be at.

Good luck with your starts!
_________________
"I am not afraid, I was born to do this."

-Joan of Arc