JoeAirPort

My Feedback: (41)

hahaha...an oil taste test. Now that's a good one. Do we have any volunteers? Does Royal purple taste like grape soda?

Truckracer

My Feedback: (19)

Ya know, it would be as valid of a test as most opinions we get on here!

Seriously though, I can't ever remember a complaint about Pennzoil! Can you?

My experiences with Royal Purple oils in automotive race engines was nothing but bad so I'd be less than tempted to ever try their 2 stroke products. Just one old guys opinion though.

flyerdave

My Feedback: (212)

I am about to cry.I just pulled the DA50 engine from my airplane,took the muffler off and boy what a mess inside .The carbon buildup was thick and looking at the top of the piston after just three gallons of run time is very disheartening.I just wonder if running Penzoil will burn off any of the crud.The sparkplug was just as bad.BTW,I'm replacing the plug,what should the gap be on a new cm-6 plug?Thanks

tkg

My Feedback: (1)

Of course after this you must tell us the oil and ratio

Truckracer

My Feedback: (19)

Regardless of what oil has been run in your engine, if the plug looks fouled and there is excessive, soft carbon on the top of the piston, the engine has been run excessively rich. I'd look at the skirt of the piston below the ring. Does it look very stained or black looking well below the ring? If so, you have ring seat issues that may require mechanical remedies. If only slightly dark just below the ring, I'd give the engine a dose of 40:1 Pennzoil and run it for awhile with properly set needles. Plug gap isn't critical ...... I've seen everything from about .018" to .025" recommended ...... I guess I use about .020" or so but really don't worry about it much as it really doesn't seem to matter all that much.

Any decent oil, mixed in the 30:1 to 50:1 range will reduce the carbon buildup if run correctly. An oil like Pennzoil will clean more than a racing oil like BeLRay, Redline, Royal Purple, etc. Its just the nature of racing oils to be less detergent. One last thing ....... can't stress enough that the needles have to be set for your airplane, elevation, fuel system, etc. There is no such thing as a factory set needle and those who insist on running factory settings usually end up with fouled plugs and excessive carbon buildup ... then wonder what was wrong with the oil they were using when it was a user caused problem.

Jezmo

Yes, the Pennzoil will help clean up the chamber but if it's real bad you might want to consider cleaning it manually. Like truckracer said, if the needles aren't set correctly it can be just as much of a problem as the oil. Partially burned fuel is left behind as carbon and it can certainly make the oil look like it's the culprit. I'm like tkg, what oil was it and what ratio?

I edited to add this link to another thread where I posted pics of nephews DA50. The pics of the cylinder and piston are after about 15 gals of fuel and that should equate to around 20 hrs of run time. It was on Redline Two Stroke Racing during that stretch and IMHO looks very clean. It had NOT been cleaned at the point the pics were taken. I wiped the piston off and reoiled it and put it all back together. He's still running Redline because it runs so clean. His is mixed at 40:1; I mix my Pennzoil at 32:1 and my chamber looks just as clean as his. The pics of his engine are in post #25.

http://www.rcuniverse.com/forum/m_9019552/tm.htm

flyerdave

My Feedback: (212)

I am presently mixing the penzoil at 32:1,just like my DL50,when I reach 4 or 5 gallons,I plan to go to 40:1

ken graham

My Feedback: (10)

just thought i'd throw this in: if the plug gap is not very important? than why is it messured to .001 of a inch?? i can still remember a high school teacher telling me that 30 years ago. i have several gas planes and the one with a bme 110 would throw little puffs of smoke out of the exhust on one cylinder at a lower rpm. i pulled the plugs out and found out that they did not gap them at the factory, or they were miss handled somwhere before they were installed. one plug was gapped within .003 of the recomended and the other was .016 under the recomended gap. i cleaned them both and regaped them and installed. now there is no puffs of smoke from either exhust pipe. and by the way the plug with the smaller gap had alot more black carbon buildup than the other plug. so if you do not get a large enough and/or long enough spark you will have some problems.

HornetFitter

My Feedback: (2)

In my Zenoah G26, I run Zenoah oil and 100LL AvGas (because I have easy access to it)...

Here is something to think about... If there is a bunch of gooey ol' black sludge coming out of the exhaust, then it's not being deposited inside the engine and the unburnt oil is admittedly messy, but it still retains some lubricating properties even after it has travelled thru the engine and made its' way thru the exhaust...