Tuning Help

[iWantSpeed]

Right i have broken in my engine, had a fair few tanks thru it, now comes tuning, I dont know wat i am really doing. The engine only has a large screw as far as i can see to tune with, What steps should i take to get the best performance outta it? Someone suggested that i close the screw completely and then open it out till i feel that it is going fastest????? but i was also told that this can make it run too lean??? Help!

 

[PiErow]

You wnat to start by getting yourself a tempgun. For the hsn(high speed needle or the big screw that sticks up on your carb) Turn it to the right 1/18th of a turn at a time(lean it) untill you get best prformance. Make wot(wide oppen throttle) passes then bring the car in and check the temp. You DO NOT want your car running at temps over 300.



That should help you .

 

[robriguez]

what type of RC do you have? Do you know what model engine?

On Most RC engines there are two adjustment screws called the HSN (high speed needle) and the LSN(low speed needle) and they adjust the fuel/air misture when either at high or low speeds...hence their names. If you turn these "needles" clockwise (to the right) you are leaning out the fuel mixture. This increases performance but decreases the amount of lubrication and can cause damage if tooo lean. Turning counter clockwise richens up the mixture and creates tons of smoke at the lossof some performance. You only want to turn these needles about 1/12 turn at a time. (about the spacing of the numbers on a clock) I would recommend that you only touch your HSN for now until you become more familiar with tuning your engine.

Read through your manual to try to locate those adjustment screws. The two things you want to try to use to tell how well you have tuned your engine is the amount of smoke comming out of the exhaust pipe and the tempurature of the engine when it is as speed. If you havent already gotten a temp guage then I would highly recommend getting one. Either a small hand held unit or one that gets installed on the engine.

You want to make sure there is a nice stream of smoke comming out of the engine at top speed. Make sure that you dont over do it. If you do the smoke will almost completely dissapear and you run the risk of damaging your engine. Once you get to that point where there is still a nice amount of smoke and the engine is running fast then you can fine tune it witht he tempurature guage. I would not recommend letting th tempuratures getting over 280F degrees (138C)

 

[PiErow]

One question how do you tune the low speed needle?

Temp or feel or something else?

 

[SokuShi]

the low speed needle kicks in while you are accelerating from a stop, if you are standing still give the engine a few revs to clear it out then go open throttle, if the engine bogs down or hesitates its too rich, if it stalls out your too lean just find a happy in between and you shouldent have to touch this needle hardly at all.

 

[militarymaxx]

LSN settings are for just off idle, that quick punch from a dead stop. After that, you're using the HSN settings. The way I set my LSN is just that, from a dead stop. With the buggy sitting still, idling, I punch the throttle wide open. I get a little smoke and off she goes. Think of the LSN and HSN as a hose faucet and a hose nozzle. The faucet on the wall is the HSN. The nozzle on the end of the hose is the LSN. The HSN affects the LSN but the LSN has no affect on the HSN. Just like our faucet/nozzle setup. If you have the faucet fully open, you can control how much comes out of the nozzle. A little or a lot. But if you have the faucet opened just a tad, no matter how much you open the nozzle, you're only going to get the rate that has been set by the faucet. Sorry, beating a dead horse, I know. And remember, small adjustments, run it some, then check. Repeat if necessary. Think of the screws as clock faces. 1/12 of a turn would be from 2 O'Clock to 3 O'Clock.
Clockwise is lean, counter clockwise is rich. This applies to both needles. Temp guns are great, but don't rely soley on them. Along with temp, sound and visual effects (smoke) are also key.
An inspection of you glow plug will also tell you alot about what your engine is doing. Fuel residue, wet looking is rich, dull gray and dry is lean and shiny and clean is just right.