hpiaddict

iTrader: (17)

I got a Losi LST2 in trade and it already had a nitro engine in it. There are no clear markings to tell what brand or make it is. I couldnt get it to start and after reading many many articles. I figured out that it was extremely rich. I found that ALL needles were set to flush. I started leaning out the bottom end hour by hour until I got it to idle. That for me was a huge success as I really dont know much about tuning. Now I have started leaning the high speed needle some and now I can blurp the throttle to rev a little without it dying out. My one concern is that the rps continue to climb until I hold the brake. I checked the carb setting and the carb is not moving when brakes are applied. Could this be a sign of an air leak?

Jerm13

iTrader: (36)

It could be a sign of an air leak...But when you lean out the high side needle ( also called the main needle) it is leaning the bottom end as well. I would richen the bottom side a couple hours and see if it helps. Once you get it to idle steady and come back from partial/WOT and idle steady, you should be fairly close to optimal settings. But it never hurts to run it an hour or 2 rich. Good luck.

HaulinBass

iTrader: (16)

if it doesnt increase with brakes on but does at neutral, your linkage isnt set up properly. do you have a throttle return spring on the truck?
You linkage should be set up so at neutral you can pull a tiny bit of throttle before the carb moves. there should be a spring and collar on your linkage near the ballcup that attaches to the carb. try to preload that spring a little bit so there is a slight bit of force(very light) holding the carb closed.

hpiaddict

iTrader: (17)

I will have to try to richen the bottom end a bit. I knew it would lean it out. I still feel like its still running very rich. I feel that there is plenty of exhaust smoke. Also still having oil coming out of the pipe. Thanks for the response.

I have 2 throttle return bands on the carb. I will definitely look at the linkage and see if there are any adjustments that I can make.

HaulinBass

iTrader: (16)

if you have band on the carb and the servo isnt pulling the carb open at neutral I would say is tuning issue and depending on the motor may be an air leak problem.
How big is the idle gap? just to be sure, everything is up to temp and the chassis is heatsoaked when your tuning?

tysonsk

iTrader: (5)

First!!! Check you linkage. If the idle increases unless you are on the brakes, that is a sign that your throttle is pulling open the linkage in the idle position. Adjust your throttle linkage before you do anymore needle turning.

+1 to what HaulinBass said. That is very important to how an engine runs and tunes.

hpiaddict

iTrader: (17)

I have not had a chance to check the idle gap or double check the linkages but it is on top of the check list for when I get a chance to mess with it. The idle will not increase when its idleing. Its only after blurping the throttle. I really do appreciate all the input. I really doubted that this thing would start and the fact its idling is amazing to me.

HaulinBass

iTrader: (16)

You did say its an lst, does the tank have the primer pump?

hpiaddict

iTrader: (17)

yes it has a primer pump

HaulinBass

iTrader: (16)

that might be your issue, all your tank pressure is blowing out the primer or its sucking in air. google how to remove that