Engine tuning question - plenty of smoke but sputters at high

[lundmatt1]

Hi, I picked up a used 8ight for my first nitro car and I'm learning the tricks of tuning the engine. I'm getting some of them down - I know how to at least tune the low and idle enough to get it started and keep it running.

When I punch the throttle it'll fly on an open parking lot for 1-3 seconds but then it sputters and seems to idle despite my trigger being all the way down. Then it will come back to life for another second or two. 1 out of 4 times it'll stall out completely.

I was told that the stuttering is a symptom of being too lean and that I need to make the high needle richer. But I don't understand why I'd be seeing plenty of smoke if it's rich.

 

[digger]

Need to get a temp guage. It is really helpful tuning these little engines.

 

[lundmatt1]

I've got a temp gauge and I got some experience using it for tuning when we leaned out my brother's car.

But with this car and engine, I can't even really run it at full speed long enough to where taking a temp will mean anything...

I'm being told it's probably a lean bog but if so, I don't understand why there's already plenty of smoke!

 

[jetmechG550]

Had the same thing happen to me mid run. After I decided to cash the round we found that my pressure line had come off at the pipe. Check your fuel lines over real good.

 

[digger]

Sorry, just took for granted being new you wouldn't have a temp guage.
My bad.

 

[.21Rc10GT]

If there is plenty of smoke, it is probably a rich bog... Well, it doesn't bog like when its lean, it sputters, as you said...

 

[neobart]

It's hard to explain but you can almost hear(or I can atleast), if it's starving for air or fuel.

 

[lundmatt1]

OK, I'm getting confused between a bog and a sputter! It sounds like understanding the difference is critical because I'm either too lean or too rich and I need to know which.

In my case it would accelerate up to top speed but as soon as it got there it would usually stay running but basically coast for a few seconds then it would kick back in. Bog? Sputter?

 

[lundmatt1]

Got it figured out!

I returned my settings to factory and then got it all worked out. I'm almost fully tuned at this point. Thanks for the input.

 

[bourney2006]

Too Rich