mikemnh

My Feedback: (8)

I have run about 1 gallon of gas through my MVVS 35. I continually get black slop out of the engine. I talked to Morris Hobbies and they suggested switching to Lawn Boy ashless 32-1 (from HP2 40-1) for break-in. I can't get rid of black goop and can't get engine to 2 cycle in mid throttle range. I have about three clicks of high throttle, then as I back off, the engine four-strokes, Morris suggested running more fuel through on the ground (it's in a WM GS Zero). Additional 1/2 hour of running, and leaning of low screw has resulted in no change in slop or mid-range burble. Any ideas or thoughts out there?

Nogyro

My Feedback: (10)

You're going to get black residue out of the engine until the rings seat. The Lawn Boy oil is a petroleum based oil and will speed this process up. Run a gallon or so of this oil, then switch to your synthetic. Lean the low needle down until it sags when throttling up, then open 1/12th turn or so. This should help out with the rich mid-range a bit.

the Wasp

My Feedback: (1)

mikemnh,,, Nogyro is right,,, every "new" gas model plane motor I have been around has spit this black goo !! even my MVVS 35, my friends BME 105 spit really bad for like 5, 6 gallons,,, I don't think your MVVS will spit goo as long as that BME because your MVVS was made differently,,,

if your motor is rich and it stops spitting, it will spit more when you lean it, then after a few flights it will stop spitting, then you lean it more and it will spit more, as it brakes-in more and more it will stop spitting,,,

a MVVS thing,,,
MVVS should tell there customers but they don't,,, when you got your MVVS did you look in-side at the black piston ?? your MVVS piston is coated with graphite, this graphite will come off and be in the black goo, and it will get in the spark plug, so you will need to clean your plug after a gallon or so (make sure to check the plug if you get a flame-out), as I found-out when I removed my plug to look at it, the graphite will chunk-up in the muffler too.

Jim

pe reivers

Jim,

you are quite right about the engine spitting black goo when not yet run in. All gas engines I know do that more or less.
However, you are not right about the graphite coating.
This coating helps run in the engine a lot without wearing down itself, and so far, when the engine is lubricated well, and cared for properly, I have not seen it come off, or foul plugs and the like.

What oil are you running? Oil to gas ratio?

the Wasp

My Feedback: (1)

Preivers,,, I am using Bell Ray H1R at 32 to 1, I have only 2 gallons on my motor, and if I remove the muffler and look in at the piston I can see the graphite coating has started to come off (or getting thin), the cylinder is not scratched,,,

I don't see how the graphite coating can stay on ??


Jim

OBDOC

My Feedback: (73)

Mikemnh,
I too have to break in a new MVVS 2.15 and would like to know which motor mount you are using. Thanks in advance.
Tim

mikemnh

My Feedback: (8)

OBDOC, I used a Sullivan anti-vibration mount for break in and on the GS Zero. It seems to work very well. I did have to plug the pressure/smoke tap on the side mount muffler, because the nipple hit the mount. Good luck with the break in.

pe reivers

Mikemnh,

I have seen engines with up to 20 gallons under the belt, and the coating still in place, albeit slightly thinner in local spots. You may fly at a field where the engine ingests air that is polluted with dust particles? In that case use of an air filter could be beneficial, or start the engine with the plane placed on a mat to avoid sand being swirled up.

IMHO, the very slight wear of this coating, which is only a few microns thick, can not be held responsible for the black goo. More so because my Quadras and Ryobis all had it. They do not have the graphite piston coating that MVVS has.