Box Stock

What are your jet sizes?

496 BB said:
Recently I havent with everything Ive done to do it. Id say every other race for last month. I got some Redline 30wt today. Think that would be ok?
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I am not familiar with that oil. I would change it after each race though. Change it right after its been running, so any particles will be suspended in the oil and come out with it. Like I said, I know Thor heavy works well in my higher hp engines, just haven't tried others.
 
Cool. Drained old oil that had 1 or 2 races on it and it looked fine.

If Im at a .024 lowside jet do you think thats too much? How would I tell with feeling it driving? It transitions fine as far as I can tell. Maybe Im leaving something on the table? .038 back in main now. Plug looked fine last race but would lowside have much to do with that?
 
The low should be fine at .024. The thing with oil is, I don't think you can tell by looking at it if it was breaking down when hot. I suggest a thicker oil, and change it after each race..thats what I do.
 
The .024 low jet is fine, the problem of running good, and still pulling at 6800, then going flat sounds exactly. like the symptoms of incorrect ignition timing for the cam2 110 race fuel. if your timing is still set for 87-93 pump gas @ say 30-32 btdc, would not be the best timing for cam2 110.
You are not burning all the cam2 @ high rpm range. You must start the spark at the right time per fuel burn rate. lite it too early btdc and combustion forces will Fight Against the piston, and wasting energy fighting to get the piston up and over tdc
fire the spark too late, and combustion energy and power is wasted because all the fuel in the cylinder didn't have enough time to burn and make efficient combustion Pressure for the power stroke, energy was wasted atdc.
I'm probably off base here, idk
i do know i don't like anything about 110-116 race fuel for clones. @
for me it's either pump gas or Methanol.
Stock clone gets non ethanol pump gas
all other builds or mods get methanol.
When ya lite the candle, Or ignition spark is the critical Point in the Timing Events in relationship to crankshaft degrees, and.piston location.
 
Idle Jet or low side

496 BB said:
So Im running the 14cc head and flattop piston .010 in the hole. BP2 cam with 1.3 rocker on intake. Stock carb bored to around .650. Last couple weeks this thing screams early on then falls flat later in race. Not sure if kart is tightening up but think not since it still handles same. Maybe air pressures I dont know. Anyways I was thinking could it be the motor getting too warm? I know guys say they like to run hot but mine seems to like cooler. I dont know what temps are but am just gauging from performance. Outside of motor temps are consistent each time I check even though I know that is not same as combustion chamber temps.

I jetted main up to a 39 from a 38 last weekend. Did not tell any difference nor did I check plug...(was in a hurry). Low side is still at 24. Running Cam 2 leaded fuel. Should I go up yet another to try to cool motor? I think it personally likes lean. Is lowside too high you think?

Wondering if this is consistent with others are running with similar builds or if I should start looking elsewhere. We run like 30-40 laps at a time on 1/10 mile dirt track. No sanctioning.
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A 24 is to big on the low side with a 38 or 39 main jet. A 37 main will work or did for me with a 24. I had the same motor setup with 93 octane before I went to Alky.
 
Clone King thx for explanation. Makes sense.

Last night ran good. Did not notice falling off. I did stick a .022 low side in there and seems it may have helped a little crispness off corners. I may try a .023 sometime just to see what it does. It was cold out last night too. Seems to like that.
 
496 BB said:
Clone King thx for explanation. Makes sense.

Last night ran good. Did not notice falling off. I did stick a .022 low side in there and seems it may have helped a little crispness off corners. I may try a .023 sometime just to see what it does. It was cold out last night too. Seems to like that.
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I bet it would have ran a little crisper off the corners with a .021... I've never had any luck going larger with the pilot jet on leaded race fuel...What was your main jet size?
 
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