New tires, new carb (losi 3.4), ended a bad day...

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Dekalb, IL
RC Driving Style
  1. Bashing
My wife got me new tires for my b-day.

Comparison to traxxas 3.8 geodes with 3.3 tires:


This was also my first run with a losi 3.4 carb on my 3.3. I have an OS21TM, but figured one last ditch effort to get a 3.3 that wasn't useless. Everything went pretty well for about 500cc's of fuel.

With the new tires, I really should have geared up at least 1 tooth on the bell, but I didn't have one. As it was, with the new carb/tires/wheels, the 3.3 was actually very responsive for a change. Pull a pretty easy wheelie on pavement and on grass. I had 15/38 gearing with the above tires.

After I went through my first 500cc bottle and a tank or so of my second bottle, tune started getting really bad. Seemed to go from stable as a rock with a clean engine note from idle to WOT, to wtf just happened, blubbery for no reason, then lean for no reason... fried my first glowplug in years today! Well, distorted the coil really bad. I haven't done that in a very long time in any of my rigs. Then the carb started binding on open and close. Then it just got stuck and I gave up. So, the $34 I spent on the carb lasted me an hour.

At least the tires worked exactly how I wanted. A bit of slip in the grass, decent grip on pavement and zero ballooning. Was really weird having to actually "steer" when at high speeds. Usually, the tires balloon up and steering input is a bit of a suggestion instead of a demand. These tires are like running on rails from idle to WOT. I did traction roll a few times on pavement, but that's my fault. They were very well balanced too. I would not recommend these in any way for cold day running or snow as you will not get any traction on any surface. The rubber is on the harder side of compounds and without ballooning, they feel more rigid than I'm used to. It was about 55F out today and they hooked up pretty good on pavement/grass.

I think they were hooking up better in the grass than I thought. After getting through that first bottle of fuel, the engine seemed to rev up in the grass when in second gear, but my speed didn't go up much. At first, I thought it was the tires. Then I was noticing it on pavement. So, I tightened the slipper, which seemed to help, but when it shifted into 2nd, it just sounded like a soft shift. After calling it a day and going home, I tore the engine out. I then realized I had put a stock clutch when I did the install. Thought I had a 7075 alloy 2 shoe. After digging through my stuff, I found why, the alloy one was worn to the springs. The stock one was half worn down just from the 700cc's of fuel from today. Pretty evident it was where the majority of my slippage was.

Well, that was my first bash day since last November when I was breaking in the 21TM. Now I'm searching for a new clutch to put the 21TM back in and will be giving up on the 3.3 entirely. Was hoping it would get me through colder/winter seasons at least, but I don't need that kind of headache when the cold is going to make things fussy anyway. Live and learn. Hopefully, this isn't a sign of things to come... lol!

Maybe I'll give one of those dynamite .19's a try for next winter... then not bash in the cold because I don't like cold.
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Thanks for the tire review Olds! Sorry the carb didn't work out. If it's any consolation, I got my clutch replaced and found an old stock 3.3 Tmaxx pipe in the bottom of my parts bin an thought "wth" and threw it at the X. Bad idea. Lol
Yup. Ran. Idled decent. That's it. So it's back on the shelf. Might have one show up next week. Got a busy weekend ahead, but Monday or Tuesday I'm pulling the motor back to see if I can find what I thought to sound like an air leak.
I think your new wheels are beautiful. Love the flat tread all the way across. I'll bet they'd be perfect on a dirt track.