houstonrevo

Hi,

I used to own a Lst and got rid of it for a REVO. I just missed the Losi so I went and got one back. It was supposed to be new but it arrived used (long story). Anyway, I was checking out the truck and noticed that the idle adj screw was screw in a lot more to get the carb to open at idle at about 1 mm. I seems to recall with my original truck that the idle screw was setting about flush with the carb. Can someone let me know what theirs look like. I am just suspecious about anything that is out of the oridinary since the seller of this truck has not exactly been up front about the condition of the truck.

Thanks

2DMaxLST!!

[link=http://www.dennisnadams.com/tmaxx/LST/idle_screw.JPG]Link: It's large for detail[/link]

Nitro Goose

I had a similar experience with one LST I bought. I'd had 3 previous to this one, all with idle screws that sat about flush to the carb body. This one had to be screwed in to what looked like about half way down. Freaked me out for a little bid, because I didn't think there would be that much difference in tolerances between engines. Nonetheless, that's where that particular engine idle speed screw needed to be to run correctly...while the others preferred to have their idle screw head flush with the carb.

Weird, huh? Maybe there's a logical explaination for it. My thought is just differences in manufacturing tolerances or castings of the block.

nebula8080

was this bought someplace far from where you live? atmospheric conditions/weather/temp/nitro/etc would explain the changes from what you remember using. You are prob. best off putting in the plug you want to run, nitro and start over on the tuning. For the idle screw turn it counter-clockwise until you hit slightly less than 1mm... 96% of the time you should be able to control the way the truck idles w/ the LSN and not the idle screw.

I've been having really good luck lately w/ OS #8 and 25% / 12% oil trinity fuel (had equally good luck w/ 20% and 8% race fuel as well..same plug).

Thats a bummer about it being used when you thought it was new. It would prob. be worthwhile pulling the motor, doing a full inspection and seal off w/ High Temp Copper RTV. http://www.autobarn.net/per81878.html

Good luck -

AKFireMedic

My Feedback: (2)

I disagree with nebula. You should not tune your LSN to make the truck idle right. You should set your HSN, then the LSN for best launch, then set the idle to just low enough that the truck doesn't move at idle. If you use the LSN to set the idle it will be muc too rich and can actually mask an overly lean HSN which will damage your engine.

sk8ingsailor

FireMedic is correct in my eye too. I think your LSN will have an effect on the idle but.....hmmmm...... how do you put this.................THAT is why the tiny black screw is called the IDLE SCREW. I have heard some people call it the idle stop screw also. This is my 3rd nitro rc and 4th engine so I am no expert, but when you take it to a hobby store such as HobbytownUSA they too use the black screw to adjust the Idle.

nebula8080

Let me clarify....

the "96%" of the time that I mention is assuming that you've already:

a.) Broken in the engine completely
b.) already gone through the iterations of HSN -> LSN -> Idle adjustment that has to be done on any new engine (or engine you dont know the last working state of).

In my experience, once you've done a+b properly its a rare occasion (assuming fuel and plug are constant of course) that you need to re-adjust the actual idle screw to get your truck to idle correctly. I'm also assuming that you aren’t constantly making fuel / glow plug changes as well. For example...its been cooling off quite a bit here in Maryland so I've rich'd up the HSN and LSN just slightly to compensate for the denser cold air. However doing so did not require an idle stop adjustment.

Make sense?

AKFireMedic

My Feedback: (2)

Yes, that is for the most part correct. Once you have everything set perfectly and the engine is broken in, you probably won't have to touch the idle screw and any idle problems you have (too fast or too slow) will be handled by simply bringing the truck back into tune again. As a side note, I have found that once the Mach is adjusted properly it reguires only small tweaks to the HSN to re-tune and I nearly never touch the idle or the LSN. Usually when I have to mess with them....there is some other problem. Hope that helps.