he is saying your LSN is rich... and to lean it out

If the idle drops and goes up again, then sorry but the lsn is lean.

i'm not doubting your analysis... just saying what i think the other guy was saying ok...

Ok..

THE FOUR RULES OF ENGINE TUNING

1. Rich is good. Blue smoke should always be coming from the exhaust.
2. Always set the high-speed needle first
3. Never try to tune a cold engine—wait for it to get up to operating temperature.
4. Always begin your engine tuning from a rich high-speed needle setting. Never start out with a lean setting.

Tuning all carburetors and Engines for the experienced racer:
1:
when starting a new engine follow the set up instructions first! Start the engine and let idle at a moderate speed for two or three minutes. Then shut it
down and let it cool for a few minutes. Be sure the piston is not at the top. Repeat this procedure three or four times.

2:
Now run the engine on the track, making sure the engine is rich. You should hear a “four cycle” sound. Be sure to let off the throttle going down the straightaway once or twice so the engine is not straining in its rich condition. Repeat this procedure for three or four tanks of fuel, letting the engine cool several minutes between tanks. Also, check the glow plug often. It should look new (shiny wire that is not distorted).

3:
You can now start leaning [turn clockwise] the maximum needle a little at a time in one hour increments [imagine the needle like the hour hand of a clock] checking the glow plug often. [I use a glow igniter with a meter on it] I recommend running a few more tanks a little on the rich side before “Race tuning” When tuning for maximum performance [Race tune] adjust until engine will reach Good RPM then open needle 1/8 to 1/4 turn.

4:
set the low end or idle:
After getting top end set close, bring model in, listen to the idle. If it is idling fast then it slows down in a few seconds, it is probably too RICH on the bottom (minimum spray bar). In that case, make it more lean (turn clockwise 1-2hr (clock method) turn), then run another lap and bring the car in again.
Repeat this procedure until the idle stays high for at least 10 to 20 seconds; at this point readjust the airscrew ( idlescrew ) so the idle is at a moderate speed. The wheels should not turn, and the clutch should be fully disengaged.

If you had to turn the minimum spray bar in more than two or three more turns recheck the slide adjustment! [Picco Torque
carburetor only]

5:
you may need to repeat steps 3 and 4 several times to achieve the “perfect tune”
Be patient. Tuning is the hardest part of gas racing, and is the first secret to race winning results. If you are a beginner, it is highly recommended that you ask your hobby shop or an experienced modeler for help.

Three last tips

1 Be sure engine is warmed up before tuning
2 always tune from rich to lean. When in doubt, richen up the maximum needle (top end)
3 If you have to turn minimum spray bar (low end) in more than three to four turns from flush, it is a indication the slide adjustment is too loose and
needs resetting (Picco Torque carburetor only).

Good Racing,
Ron Paris
Paris racing

another good chart

TUNING
This chart indicates the direction in which you should adjust the fuel mixture when faced with changing weather and other conditions. It assumes the engine is currently well tuned. You could face any combination of conditions listed in the chart; knowing which way to go with the mixture adjustments is half the battle.
Higher air temperature Lean
Lower air temperature Rich
Higher humidity Lean
Lower humidity Rich
Higher barometric pressure Rich
Lower barometric pressure Lean
Higher altitude Lean
Lower altitude Rich
Higher nitro content Rich
Lower nitro content Lean
Higher oil content Lean
Lower oil content Rich
Hotter glow plug Rich
Colder glow plug Lean

Awesome write up Ron.. There is allwase something to learn when it comes to tuning i find

What you say is so true about people trying to tune cold engines, It takes more than a few laps to get your engine up to temp and get the chassis ect soaked thermaly.... Few people relise this




Dave

Had opt for a 9853 SS tune pipe. It was crazy power for my buggy. Problem now is i could only manage 8min runtime compared to my 10min when I was running the 9901. I havent done/change anything, but I need my runtime back.

Suggestions?

The gentleman, Ron Paris, who wrote that tuning article several years ago is deceased. He was one of the best engine tuners in the world and a great man.

i recently got a 2009 model 21+4 blah blah blah. im using this engine on my eight-t 2.0

i think this engine is weak as shit & its got no balls whatsoever. (weak as hell on the bottom, and no top end)

im curious what i can do to make it seem like its got bigger balls than it really does. ?
ive been getting smoked consistently by "cheaper" engines.

also, clutch bell bearings are being eaten in a matter of minutes.. probably 30-45minutes of run time and they are shot

clutch springs/ shoes ?
different pipe ?
carb restrictor ?
clutch bell gear change ?



im currently running 41021 manifold/51016 pipe

clutch springs are 2 black/2 silver with aluminum clutch shoes (not sure what shoes, 2 look like they have green on them)

clutch bell is i believe a 13tooth (50 spur, or whatever stock is)



im going to be replacing my clutch assembly very shortly, perhaps even tonight and would love a suggestion or 5.

41021/9853ss had plenty of power for me! could still pit at 10 minutes at my local track! this combo seems to wake the bottom up a good bit and i didn't like all the snap it added. IMO, the 41021/9901ss is perfect. it offers a little better mileage and a smoooth power band. both combos would run with anything at my track!

I'm running it in my 808 which is lighter than a truggy but it has plenty of balls with the 9901/41021 setup and an ascendancy 4 shoe clutch. What are your needle settings?

41201 header 9953 pipe for the truggy 7mm restrictor. Gold springs with the aluminum shoes and green springs with the carbon shoes. Clutch bell bearings failing is not the engines fault, maybe your gear mesh is set wrong? Is there a track near by where you live? Real hands on help is the best thing.

try using the 6mm carb insert, and set your carb slide so the barrel doesnt open further than what you can see through the 6mm hole. My friend told me this is how drake sets his carb slide. makes sense to me.

correct on the full open setting. It should be just a couple of mm more than the restrictor. For Truggy I run Plus 4 c with 41021 header and 9853 pipe. This combo will produce the most power at the cost of runtime when compared to the 9901 and same header. I run the either the 7 or 7.5 mm depending on the track. Your needles will be around flush on top and in from flush about a full turn. These will get you close. This engine is more than enough for my truggy and I get great run time. 11 - 14 depending on the track.

I forgot to mention my clutch set up

for truggy I run aluminum flywheel with 2 alum shoes and silver springs and 2 carbon shoes with gold springs. This is with the regular 13 tooth clutch bell and 48 tooth spur.

when you rebuild your clutch you will want to get a clean sanding drum on your dremel and lightly sand the inside of the bell to get any and all contaminants off. It will be nice and shinny when its right. Also you will need to spray out your clutch bearings otherwise the oil from the bearings will get on the bell and shoes and cause it to slip. If you run all aluminum shoes you can skip this step.