Oooh a triple within .001. That’s pretty darn rare. You get a cookie:
Every kart at every cup karts race looks exactly like this. Get them boys stretched out
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What’s the deal with stretching tires to fit rim? Aesthetic? Broke?
How will you clean the rears?
Less sidewall effect frees up the kart vs narrower rear wheels
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Figured it had been done in some briggs classes. This kart is going to be interesting to drive I think 
. Tires intended for 8-10 HP on a kart running 18-22
Just saw the r70 is available in 7.1” rear, guess I should have grabbed one of those. I’ll need a different tire pressure gauge too, mine only goes up to 15psi.
Pick up on the tire is from not working the tire hard enough to clean itself off in a run. You’re getting it up to temp enough to melt the surface and allow for it to suck rubber off the track. The tire isn’t slipping at all so it never cleans up, so you’re not sliding the rear.
You’re either not driving at the tire’s limit yet or the kart is stuck and needs to be freed up. Or both.
At 395 lbs in a 206 on a semi-soft tire, it’s going to be work to free that kart up I would imagine.
As an experiment, see if going to 14-15 psi on just the rear tires changes the wear. I would bet it cleans up a bit, though that pressure would be a band-aid fix and not an actual solution to the handling problem.
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Add to what TJ said, be mindful of where you drive on the track on your cooldown/pit in lap. Stay on the racing line if it’s safe to do so to keep your tires clean.
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I did just that coming in so I had as little pickup as possible on the tires. I was running hard enough to be within 1/3 to 1/2 lap (1/4 mile lap) of the fast kart so I’m leaning toward setup issues more than driving although it’s likely still part of the challenge. I found as I’ve freed the kart up my driving improves with it - I can get the kart to go where I want it to go more easily. It seems counterintuitive to go up instead of down on pressures - IIRC higher pressures heat the tire up faster. 
I’ll definitely try raising the pressures next time I’m at the track and see what happens.
Here’s a better pic of the left rear where I didn’t have a chunk of pickup. All four tires used to look like this so there is progress being made! What changes would you suggest to help free up the kart at this point? I’m not sure what the max rear width is for the Ignite, I’m at 52" now.
Our kids ran Quarter Midgets before my son and I started racing karts. They clean their tires off after every session since they don’t have enough time to get them clean on track before the green flag flies. There are several versions of this that you can find online that attach to the end of a heat gun. Google “quarter midget tire scraper” and you’ll see several versions. I like this one since you pull it back toward you and you can see what you’re doing. It gets all the buildup off the tire and gets back down to the clean rubber. It doesn’t take the clean rubber off the tire though. Sorry for the potato pic… If you want I’ll see if I can do better in a little while.
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The tire isn’t overheating. Well, the surface isn’t overheating at least. If it were, it would get greasy and start to slip, which would eliminate pick-up.
Not sure what Margay suggests on the Ignite or how much tunability the chassis has, but I’d be looking at an axle change.
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So I’m seeing a weird little groove in the exhaust side of the piston. Rest of the cylinder and piston coating looks great. Anyone seen this before?
This?
Do you have footage of this one in action yet? This is your 4-stroke shifter, yes?
Only a short clip on the dyno today at 1/4 throttle. Planning on heading to the track this week with it once I have it dialed in.
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Yeop. There is a nice little gouge. Catches the fingernail. I’ll have to pull the combustion chamber to see if there is a matching mark in the cylinder on that side.
Kinda interesting that the metal below it bows.
Not yet. Was planning to this past weekend, but didn’t realize my X30 kit didn’t include an exhaust hanger. So off to Comet Karts Sales I go to order more parts and give it a shot next month. Daughter still got to race, and picked up a P-1 finish so it wasn’t a total loss. (Given it was a small cadet field of only 3)
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