Moki/Mark G140RC rod failure

dieselcrazy

Well-Known Member
Hi All,
I thought I would start a tread and post as I learn from this incident.
Here is what I know so far.
100% premium gas octane 91
Morgans Cool power oil at 24:1
Timing, not know at this point when engine is reassemble I'll check it.
prop is APC 18x6w turn 7800rpm
temperature of engine running unknown.
engine runs inverted (shouldn't matter?)
rod has no holes drilled in the ends
 

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red7fifty

BadAss Member
Hum?
What are we looking at? Crankpin damage?
I have a small BME 90 (converted SuperTiger .90), has similar construction on the inside. I have not run mine yet.
The needle bearing has enough opening at the crank pin for oil......it shouldn't need an oil hole, as in a nitro engine....but, that is my opinion. BME says 32:1 oil on their website....and an email to him, says Redline 40:1 "Should work"
Your 24:1 mix is very oil rich......should have a lot of protection.
When TOM/PAT gets here......maybe he will shed his input.
 

dieselcrazy

Well-Known Member
Did you check your BME? I talked with them the other day and if I recall correctly they are putting holes in the end of the rods.

Two gallons of fuel.
 

dieselcrazy

Well-Known Member
The spark plug had a layer of black carbon on it, the piston had a thick layer of carbon built up on it (like 6 paper thick).
 

red7fifty

BadAss Member
What type of gasoline are you using? Blended?
I am NOT a fan of ethanol-blended gasoline.....in my opinion, the alcohol blend causes all sorts of problems.....corrosion, attracts moisture, affects rubber parts, etc.
Even in my full size car, I use non-ethanol gas....but, that is not available in all locations.
 

red7fifty

BadAss Member
Next time you are at the gas station, look at the pump, for signs of additives/blends.
MOST gas stations blend ethanol in the gas.
 

Tired Old Man

Staff member
dieselcrazy and I spoke on the phone this morning and I couldn't put it together. The photo at the top helped a lot though. The bearings are galling the crank pin due to poor lubrication. Perhaps discontinue use of the Cool Power and just go with the Echo you have been using at the same oil ratio. Based upon your mention of friends running similar engines without issue using different oils it's worth a try.

BTW, thanks for your patience this morning and sorry I was late. I mistook the Central time zone for Mountain.
 

dieselcrazy

Well-Known Member
I went and got fuel tonight at the same place I get gas and double checked 100% gas no ethanol. Some additives are added, what ever Shell uses.

I got the parts today and go my engine back together. I checked the timing, it is set to fire 15 degrees before top dead center. It's a SV ignition.
 

dieselcrazy

Well-Known Member
Hi Tired Old Man. I think you miss understood me this morning, my friends are running Cool power oil in their small Evolution engines.

No worries, I appreciated the call.
 

dieselcrazy

Well-Known Member
I have no experience with Morgans Cool Power oil......is that oil recommended for Gasoline pre-mix?
Cool power and Omgea will mix with gasoline

According to Fred at Morgans, Cool power oil is the same oil that Evolution is selling for their small gas engines.
 

Tired Old Man

Staff member
I did, I thought they were using something different. My error. In any case the bottom is not getting as much lube as it should. The carbon depth you described is from running rich and cold but with the bottom failures I wouldn't be in any hurry to change the mixture.
 

dieselcrazy

Well-Known Member
Thanks for the information. I would going to run the engine but now will wait till I modify the rod with the additional oil hole.
 

dieselcrazy

Well-Known Member
Just got off the phone with Morgan fuels and this is what I found out.
So DO NOT MIX COOL POWER OIL WITH PETROLEUM OIL! It turns into a redish or black goo.
I was mixing the synthetic Cool power with Echo petroleum oil. Lesson learned.
 
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