Leopard Temps / Carb Tuning

Pirooz Javan · Joined: 16 Apr 2010 Posts: 45

I just got my lap data off and put it into the RS2Analysis AIM tool (VERY COOL!)

At the track this weekend (very short track), I noticed I wasn't getting the temps (water = 105, exhaust = 720) where I wanted after two runs. I put some tape on radiator and dialed in the high needle from 1 1/8 to about 1. Outside temperature was 65 and sunny.

I only got one more run in and downloaded data:

Max RPM 14752
Max Water = 152 (overdid the tape here)
Max Exhaust = 762

I kept up with the front pack on the only straight there was. I guess my question is am I leaving power on the table to be had here? I keep hearing the recommended performance marks of 16.5k rpm and 1020-1040 exhaust and I'm not near there. Any suggestions on how to get there?
_________________
2007 Birel M31
Stock Leopard

Dan Haynes · Posted: Mon Mar 12, 2012 8:20 pm Post subject:

Do you have the jam nut on the EGT sensor? If so, the tip of the probe will not be in far enough to get an accurate reading. You want the tip to be in the center of the exhaust flow for most accurate readings.

How does the plug look? Flex? The flex should be dry and have a tannish tint.

Check this stuff before running it again. I'm sure you know what happens when you lean it too much Shocked

_________________
Blaise Haynes
#3 Arrow X1-CIK
TaG
Cook Racing Engines Parilla Leopard

TJ Koyen · Joined: 03 Oct 2004 Posts: 1461

14.5k is way low for RPMs. What's your gearing like in relation to the other guys?
_________________
T.J. Koyen
OKTANE VISUAL - Custom Helmet Paint & Graphic Design
www.oktanevisual.com
www.facebook.com/oktanevisual
--------------------------
DB Motorsports
Exprit/Leopard

al nunley · Joined: 13 Nov 2006 Posts: 3066

I think Dan has some good points. One other is; where is the exhaust probe. What distance from the piston face. Is it "about" the same as others.
_________________
If the data does not support the theory, get a new theory. (Al Nunley)
All else being equal; Compression is the Holy Grail.
45 years, in and around karting

Pirooz Javan · Joined: 16 Apr 2010 Posts: 45

Thanks for all the replies. I do have the nut for the exhaust, but what would be the difference that would make? Let's say -100 or so? It can't be the range I'm at. It's also placed consistent with where others are at.

I'm running 11/83 which is consistent with others at the track.

So from what I'm hearing...the things to consider are:

gear ratio
plug condition
flex condition

Glad nobody is recommending turning in another 1/8 on the carb right off the bat. I don't want to stick the engine.
_________________
2007 Birel M31
Stock Leopard

Matt Dixon · Posted: Tue Mar 13, 2012 10:22 am Post subject:

The needles are like a water faucet, sometimes you got to close the cold water to make the water hotter... wheres your low speed?
_________________
Matt Dixon
94y Energy Corse/Swedetech

Dan Haynes · Posted: Tue Mar 13, 2012 1:26 pm Post subject:

Take the nut off the sensor then try it. I bet your temps come up quite a bit.
_________________
Blaise Haynes
#3 Arrow X1-CIK
TaG
Cook Racing Engines Parilla Leopard

Juan D Gomez · Joined: 28 Apr 2010 Posts: 273

After reading this yesterday and looking at my kart I realized I had the jam nut in the EGT sensor.
So, I decided to give it a try and take it off to see what the difference in temperature is.

I screwed it back on and when it got to the point where the jam nut was I had to use a little more force and SNAP!!! Evil or Very Mad

Broke the stupid sensor and now I have a headache trying to get the stupid tread out. aggggg!

So let this be a lesson to everyone so it doesn't happen to you.
Don't force the sensor all the way in! and maybe the jam nut is there for a reason.
Adjust your readings. Who knows what the temperature differential is with/without nut?
If you are shooting for 1000deg or so. Is that with or without nut?
_________________
NTK/LSGP
KART/MARRS
Arrow AX-9 CIK/MISI Parilla Leopard
"Of course I don't look busy, I did it right the first time"

Jeffrey Dyer · Joined: 30 Aug 2009 Posts: 155

14,700 rpm is low. More gear. I would shoot for 16,000 to 16,500.
_________________
I live an " Explosive Life" but I sure love racing!!!

Dan Haynes · Posted: Wed Mar 14, 2012 9:04 am Post subject:

hmmm...that sucks about the sensor snapping. I don't know of anyone that runs the jam nut. Maybe it's there in case you thread directly into the pipe wall. If there is a bung welded on AND you use the jam nut then the tip is way outside of the exhaust flow. I would think that would cause erratic readings but have never tried it.
_________________
Blaise Haynes
#3 Arrow X1-CIK
TaG
Cook Racing Engines Parilla Leopard

Jim McMahon · Posted: Wed Mar 14, 2012 10:47 am Post subject:

How is the color of the inside of the exhaust header? EGT is only useful is you have other data to co-relate it to IMO. The color of the plug, head, piston crown and exhaust header will tell you where your jetting is at. Don't both chasing revs until you feel your jetting is in ballpark.
_________________
CES Grattan pre-entry is open. TaG, Shifter, KPV, KT100, Animal\LO206, enduro or superkart.
Click Here to enter Grattan online

al nunley · Joined: 13 Nov 2006 Posts: 3066

Bummer about the broken sensor. My guess is the threads in the header got a lot of “stuff” in them and should have been cleaned out with a tap.
Not much help now though.
Still, if the sensor isn’t in the center of the flow, you get bad information. I would call the manufacturer and get their view on this problem.
_________________
If the data does not support the theory, get a new theory. (Al Nunley)
All else being equal; Compression is the Holy Grail.
45 years, in and around karting

Pirooz Javan · Joined: 16 Apr 2010 Posts: 45

Sucks about the needle breaking. I think in my situation the right thing to do is check the plugs and only minor adjustments to the high needle on the carb. Going up from 83 to 84/85 seems to be the most reasonable first choice.
_________________
2007 Birel M31
Stock Leopard

TJ Koyen · Joined: 03 Oct 2004 Posts: 1461

I'd double check your front sprocket too and make sure it really is an 11t. It's hard to think you'd be down 2k RPMs on the other guys on the same gear.
_________________
T.J. Koyen
OKTANE VISUAL - Custom Helmet Paint & Graphic Design
www.oktanevisual.com
www.facebook.com/oktanevisual
--------------------------
DB Motorsports
Exprit/Leopard

Pirooz Javan · Joined: 16 Apr 2010 Posts: 45

TJ,

Good thought. I actually was running a 10T.

On a side note, I know this depends highly on weather conditions, but I'm curious to know what everyone sets their Low/High to as the default before adjustments? I'm hearing a lot of variance at the track...
_________________
2007 Birel M31
Stock Leopard