Spark plug is black, clutch springs, and glug recomindations please

[joshreynolds777]

That means its been running too rich right?


so lean up the high side needle. Still on the very first tank. Havent read anything on break in procedure, so any thoughts on that?


Nice and Doggish on low end... how hard is it to change the springs in the clutch in these things?


Also the plug the guy had in it is an NGK CMR7H.


What plug do you guys recomind in the MT5?


Thanks guys

 

[Gas Jocky]

Yup black means rich, try to run your truck wide open for a bit then bring it in fast and shut it down quickly, check your plug then. or use a 3rd channel kill switch if you have one installed. If you have it idling awhile before you shut down you will get a kind of a false read on the plug.


Clutch springs are pretty easy or hard if you don't know how, remove the clutch shoes from the engine then simply twist the shoes like you would a rubics cube, now just reverse the steps to reassemble them.


The cmr7h is the right plug, that's what I use with no issues but some prefer the iridium plugs, there are 3 or 4 plug options I think.

 

[DemonRC]

Yes it's running rich would could explain some sluggishness. Try turning the High needle in 1/16 of a turn clockwise, check the speed, and then check the plug. Keep repeating this process untill your plug is brownish and dry. This would indicate the engine is running at ideal conditions and you would be running as fast as the engine is capable of.


I'm on the west side of Houston, near Katy, if you ever want to install a new headkit and need somebody to do it, just let me know.

 

[joshreynolds777]

cool guys


I'll try leaning it some and test...


What are the signs of too lean with these motors?


Im used to nitro.


And do these plugs ever foul?


how do you know when its time to change them out?

 

[joshreynolds777]

oh and I'm about to mix a tank of fuel...


1:25 Ratio right?

 

[kryptonite]

cool guys
I'll try leaning it some and test...


What are the signs of too lean with these motors?


Im used to nitro.


And do these plugs ever foul?


how do you know when its time to change them out?

small increments is the key. 1/16-1/8 of a turn max on the needles. the best way to tell if its lean is by the plug. do some high speed runs and "quickly" kill the motor as soon as it comes back to you. a 3rd channel kill switch will help. from that you can check the plug for color. black is rich, chocolate brown is good and grey/white is lean. you can also hear it in the motor, but you cant tune by the sound like a nitro. if its lean it will crackle or stumble at max rpm. the plugs do foul. mainly from a rich tune. with a decant tune you should get 1-2 seasons out of it. i mostly change them out of boredom.

oh and I'm about to mix a tank of fuel...
1:25 Ratio right?

25:1 is perfect for break in or everyday running. a synthetic oil is best. i run 32:1 mix, but you have to keep an eye on the tune

 

[joshreynolds777]

I picked up some Motul 2 cycle oil from a toy shop


they said its the best. So far so good at 25:1.

 

[C-Mac]

I ran 32/1 and it still seems rich, is that normal?