CKRC Forums

What is the main jet for our altitude at the track on a 10-25 degree day at the track.

Briggs recommends a size 95 main jet.
-is that at sea level, 21 degrees celsius?

I see that there is a multitude of main Jets to use I’m just trying to set a baseline at the track for what main jet to use and then I will take it from there.

There is a lot of tuning guides from Briggs to a nice one from tsracing, most is base line setup to what I believe is at sea level.

The last weekend it sucked to be equal with people in the turns only to watch them slowly pull away on the straits.

Thanks everyone

I have no clue on the jetting but you sure it wasn’t a gearing issue? What sprockets were you running?

Hey Michael ... this copy/paste from the Briggs regulations we are subject to ... (http://www.asncanada.com/wp-content/upl ... -Mar25.pdf page 9) ... perhaps worth a read.

"Both idle and main jet must remain stock, as shipped from the factory."

Which I read to mean we do not touch it ... there is only 1 main jet to use in an LO206 ... one of the many things we leave alone.

DaveC wrote: ↑Tue May 28, 2019 6:07 am Hey Michael ... this copy/paste from the Briggs regulations we are subject to ... (http://www.asncanada.com/wp-content/upl ... -Mar25.pdf page 9) ... perhaps worth a read.

"Both idle and main jet must remain stock, as shipped from the factory."

Which I read to mean we do not touch it ... there is only 1 main jet to use in an LO206 ... one of the many things we leave alone.

Found it,

Both idle and main jet must remain stock, as shipped from the factory

understandable, glad I asked! Thanks Dave

If your really convinced it’s a carb thing you could try playing with the pin height. It’s likely either a setup or gearing issue however though.

Jackmazury wrote: ↑Tue May 28, 2019 7:52 am If your really convinced it’s a carb thing you could try playing with the pin height. It’s likely either a setup or gearing issue however though.

Without a doubt Jack, I'm sure it is a setup thing.

Been playing with the kart ever since I have gotten it. adjusted the floats last night, I also have a lot to learn on front end set up , tire pressures, chassis setup, gearing, I do know I have a long road of learning in front of me, I just thought i might have been out to lunch with the jetting. but as it stands looks like jets are not the answer. haha

Thanks for helping me out as per usual guys, this is why CKRC is the best, everyone has a helpful hand. Stoked for the next time I can get out on the track.

Are you going to be at test and tune tonight? I could maybe help get you started on the right path with the setup.

Jack

Jackmazury wrote: ↑Tue May 28, 2019 10:16 am Are you going to be at test and tune tonight? I could maybe help get you started on the right path with the setup.

Jack

Unfortunately no, I have to work, the joys of working shift work in aviation. Im going to have to scrounge a test and tune date before the 9th, ya the next time I see you at the track I may pick you brains for a few mins while you are not waving flags, and watching the track.

What I've found as a rookie so far Mike:

1) If you're seeing ppl pull away in the straights they're likely running a taller gear. Andy commented on this with my kart when I think I was running my 61 or 62 in the back, but I was never finding the limiter. Now I'm finding my limiter up the front straight and before the hairpin into the chicane (with a 60 in the back) which many tell me is what to expect. The shorter gear in the back is helping me compensate for my lack of consistency in the corners with a little more acceleration yet so might help you.

2) I've been messing with tire pressures a lot as I know the impact they have in my car at autocross, in the cooler temps when I seen you last that 14 PSI cold mark was proving to be the spot for my most consistent runs and consistent feel of traction, but I have a hunch I'm going to like a little lower with the warmer temps and will test that next (and see a few others like that 11-12 range.)

3) Are you pushing the wheel to turn to push your body weight into the back corner of your seat toward the outside of the turn? This still feels counterintuitive and I find I'm not as consistent as I need to be yet in where my bodyweight is going, that and too aggressively turning in on a couple of the tighter corners which I think is giving me the loss of rear traction and loss of momentum as I correct (compounded by making adjustments for fitting my lack of height comfortably in my kart, but I think I have that sorted now.)

When I seen you last I noticed you had front torsion bar in, did you take it out? Consensus I've got so far is for baseline leave that out until you stop improving.

Don't know if that helps, but these are the things that found me a couple seconds, anxious to get back on track again.

If you are seeing people pull away from you on the straight, there is a very good chance you are trying to go in too hot, and are losing out on exit. Also possibly getting on the throttle too early, which drops the inside rear wheel, and causes the front to plow through the exit, which means you will be turning the wheel slightly to compensate. ANY amount of steering on exit will slow the kart down drastically.


Phil