Hi All,
My daughter has a 100J with clutch in a cadet kart and has been to the track a few times but she's still not reving out the kart on the straights and coasts a lot through corners. The kart has a lot of power and is really responsive, so no issues there.
The issue we have is that once she does a couple of sessions, the kart doesn't run once started and coughs/splutters to a halt soon after driving off. So i have to then run it on the stand at high RPM to clear things out before trying again, which doesn't always work. I think she's either fouling the plug, or flooding the engine.
- We're running 20:1 fuel, should i drop it to 30:1 or even 40:1?
- The AKA intake has one air vent blocked off, would it help having both open?
- What settings on the carby would best suit a real beginner for L and H?
Thanks!
Comments4
Your fuel/oil mixture will depend a bit on whether it is castor/synthetic, or full synthetic. We always ran castor/synthetics at 20:1, and if running full synthetic, no less oil than 25:1. Your engine needs the oil.
Running one air intake hole blocked is recommended for a J. If you run both open, you will find most likely that the engine needs to be continuously choked for a couple of laps, as it coughs and splutters due to being too lean, until it gets up to temperature.
Now, the most likely problem is that the engine is not being worked hard enough, and that the plug is fouling on you. The usual settings for a J are 1.5 to 2 full turns out on the low, and possibly no more than 1/5th of a turn out on the high. Those settings will depend somewhat on how the carby is set up, and what the pop off pressure is.
Having said all that, I had a kart and KT100J available at a come and try day at our club a few years ago. As the drivers were inexperienced, none of them worked the engine at all hard, and we finished up with less than 1 turn on the low, and the high closed off, and still risked fouling the engine.
Those settings in hard racing would certainly kill the engine, most likely by seizure.
Thanks for the reply Terry, much appreciated!
So even for a newbie i should keep one intake hole blocked?
So with the Low at less than 1 turn out will help prevent plug fouling?
Will try this and see how she goes!
agree with terry, if its not been revved out then definitely around 1 on the low will be ok. any lower and they tend to flatspot. the high jet i used to just crack open the width of the needle when teaching. this way if it revs higher then it wont loose all fuel.
you can also try running a hotter plug. i used to run a NGK-9egv plug for racing but a 8egv for runing it in to prevent fouling.
Definitely i wouldnt recommend iridium plugs until you are well up to speed.
Another trick for learners is to run a higher rear sprocket. it will help keep revs higher. as she builds confidence you can bring the teeth back down.
Thanks Ben! Will try the 8EGV as well