will changing springs in a lo206 do anything

You would be wasting time and money if you even consider touching what seems to be a well running engine. If you are intent on spending money do it by getting seat time. With LO206, WF, or any "Stock" type 4 cycle classes the engine is the last place to look. On track time end chassis/driving adjustments will pay off in a much bigger fashion.
 
It just wouldn't idle. Runs great on green flag. Went to the middle needle setting and backed air fuel screw out a lot. And its better. Still not perfect by any means. I just don't know if after it warms up if its getting to much air or fuel that causes it not to idle.
 
dodgeram11 said:
It just wouldn't idle. Runs great on green flag. Went to the middle needle setting and backed air fuel screw out a lot. And its better. Still not perfect by any means. I just don't know if after it warms up if its getting to much air or fuel that causes it not to idle.
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Try a higher carb float setting maybe .890-.900, decent idle should come @ 1/2 to 2 turns out. Staying within the rules all you can do is mess with float height and needle to get decent air fuel numbers. I would change valve springs once a season the briggs springs are cheap easy to change and legal , they do lose height especially on the exhaust side. Good Luck.
 
Your idle air screw 4 turns out, you are at a risk of loosing that screw, there is not much thread left it will vibrate out. You may also be drawing air around it's threads. Setting the float at 900 is not leaving much fuel in the bowl, you better have smooth corners. If it is not idling properly you need to investigate, this engine should sit and idle all day. Did you align the carburetor bore with the intake adaptor, there is a little to be found there. Did you check the coil gap, take the recoil cover off and inspect the kill switch wire, we found one the team thought they were hitting the limiter when actually they had a pinched lead that caused a misfire it got worse as the vibration increased.
 
Our corners get rough some times. And it will not idle all day. And nobody at our track really has there's figured out. What should coil gap be. I always use 87 octane with no ethonol. Woukd a higher octane help?
 
I have no idea I just turned it in til it wanted to go on its own then I backed it off a little. And moved air screw til it sounded the loudest
 
You should invest in a tach. WF or LO206 I usually set the idle at or above 2000 rpm. It'll keep the engine running during spins or off track ecursions and your idle adjustments that everyone seems to fret over are of minimal consequence.
 
You do not need higher octane, turn the idle air screw to about 2 turns out. Use Briggs recommended 22mm float setting till you get knowledgeable about the carb set up. The air gap for the coil is marked on it .016" and they work well at .020".
 
I have it at .02 and .870 is where Carlson motorsports told me to set it. How does the number work. Is it higher means means more fuel in bowl or less.
 
dodgeram11 said:
I have it at .02 and .870 is where Carlson motorsports told me to set it. How does the number work. Is it higher means means more fuel in bowl or less.
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22mm=.866" so you are correct in that setting. You are measuring from the gasket surface to the bottom of the float therefore the larger the measurement the less fuel you havein the bowl, or the smaller the measure the more fuel. Example .870 has more fuel than .900,---- .870 is richer than .900
 
I thought .870 was how much fuel was in bowl. And that being lean or rich had to do with main jet/ needle setting and air fuel screw.
 
The height of the fuel in the bowl is controlled by the float and the needle and seat valve, when you adjust the float height you are controlling the amount of fuel that is stored in the bowl for immediate use. The higher the fuel level in the bowl is a shorter distance for the fuel to be pushed up the main nozzle into the venturi of the carburetor, think of the effort required to drink a soda with a short straw compared to a long straw.

Rich/lean air fuel ratio from partial throttle to almost wide open throttle will be affected by the taper of the needle and the clip position, the main jet has an effect on the A/F ratio across the same range especially at wide open throttle.

There are several circuits that overlap during the operation, the overlap prevents flat spots from leanness and/or bogs due to over rich conditions.

.870 or your preferred setting is simplyan easily determined position to do repeated measurements. The float is partially submerged, and it's volume displaces some fuel. Remember you are setting the float level with the carb upside down and it is the point that the needle seats stopping flow.
 
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