Problem Please give advice. . .

[Nitro New Guy]

Ok here is the skinny. I have a 1/8 Scale Ofna Ultra mbx Pro I got it off Craigslist ( I know its hit or miss. This thing looked pretty goood to the eye. I see nothing wrong I have went over the whole thing it was dirty but nothing bad at all. Ok Now I have a problem with the idle I can get it wunning at a high Idle and take out the glow igniter and it will stay running for a little bit then whne I tap the throttle it will run high and then just cut off before it gets back to idle. I have started with the HSN at stock posision. I am stumped and I did not and still do not wantto play with the LSN. Now also the Idle screw id bottomed out and I am not sure it will hold a decent idle. I am at wits end I have been playing with this thing trying to fix this problem for almost 3 days. I think I need a little help please.

If you need any info ask and I will make sure I give you detailed info for the answer I really would like to get this thing running. Thanks. . . :\

 

[Zdragon71]

Idle gap needs to be 1mm. Try to lean your hsn a tad at a time and see if you can get it to idle. If not then try to lean your lsn an hour and go from there. You can also follow the tuning chart located in the sticky section of nitro talk or try this link also.
http://www.extremercmods.com/content/tuning-popup.html

 

[srusinek]

Here's the first thing you really need to do: Get the user manual aka the owners manual. Then once you get the engine up to operating temps or even warm, then you can set the carb to factory settings. Also if you're trying this while it's cold outside, it might be harder on the engine due to the cold. Next time you go out make sure you're receiver batteries are charged and the warmer is charged. If you're still stuck, please feel free to post the issue you're having and were here to help.

 

[Nitro4910]

There is no "Idle screw", you set the Idle by tuning the LSN & having the Idle gap set correctly.

You will need to reset the idle gap if thats what you were using to try to set the idle speed, 1mm is pretty standard & you can use a #60/#61 drill bit shank to reset the idle gap.

Z linked you a great tuning guide, here is another good one.
https://www.rcnitrotalk.com/forum/showthread.php?t=60832

 

[JoeMAXX]

I have never bought a used R/C because most of the time they are selling them because they want something new or there is a problem they cannot fix. In your case what I would do is pull the head off the engine and inspect the piston sleeve. My guess is it has might have got dirt into the engine. If the piston sleeve is clean then I would look at sealing the carb seals with a little Copper Sealent. I prefer the Copper type over the black Sealent because it has a higher temp range and will stand up to the fuel and engine cleaners better. I have run a cheap filter once and only once on a really expensive race engine and it allowed a little bit of dirt into my engine. I had to replace the engine and chose a better filter system for this engine.

Watch this [ame="http://www.youtube.com/watch?v=6xwDy-I0Z4I"]How to seal an RC engine from air leaks - YouTube[/ame]