tuning

[raaazzzeee]

i am trying to tune my .27 egine on my 1/8th scale buggy I'm afraid of overheating by leaning it to much(i have no temerature gage) I'm at about 4 1/4 turns out wich seems to rich but if i lean it anymore it emtis very little smoke what r ur sugestions for tuning wihtout a temp gage???

 

[sweetdiesel]

You should have a nice trail of smoke at all times. Check the LSN by pinching the fuel line, it should take about 2-3 seconds to die. If it cuts out sooner the LSN is too lean.

 

[raaazzzeee]

how nice is nice? i usallly have a thick trail in acceleration then at top end at thin trail.

 

[GoVert]

Every thing that I have read says to start rich and move lean with 1/4 turns or less and take it slow. The last thing you want to do is blow your motor. Look for the obvious: blue smoke through the entire rpm range, no smoking engine, the engine is startable, etc.. You can not use the temperature alone to tune your enging and the better tuners will tell you that it is a combo of the amount of blue smoke, sound, responsiveness, changes in idle speed, and heat.

Just keep it simple and start with a rich mixture that will get the engine started and allow you to run it. Start with small turns to lean out the mixture and give the engine time to work through the change ( a couple of high speed passes) before making another change. Untill you have a better feel for you engine do not worry about "fine tunning" for race day. The last thought is your LSN, follow the same theory as with the HSN.

I hope this helps.

 

[raaazzzeee]

thanx for the help i will be sure to do that first thing tommorow.

 

[GoVert]

A couple of assumptions that I made.
1. That you understand that Blue smoke is a good thing. That means the engine is getting enough fuel to keep it lubricated. To much blue smoke means that the engine is running rich and you will not get good power, also known as running sloppy, but at least you are not under lubricating your engine, because that can do alot of harm.
2. Counter clockwise turn is for more fuel (richen) clockwise is for less fuel (lean out).
3. The best way to test the LSN is the pinch test. When you pinch the fuel line to cut off the engine it should run for 2 to 3 seconds, go up in rpm's slightly, and then cut out. If it runs for more than a couple of seconds you will need to lean it out, if it cuts off right away then you are not running rich enough and will need to richen the mixture. Always make the LSN adjustment last.

Let me know how it goes.

 

[raaazzzeee]

i just finished tuneing i emit alot of smoke in acceleration but at topend only a little trail also when i slow down it makes kind of a sputtering noise dont know why