Hey Guys, I've got a Saito 62 four stroke turning a 12x6 prop and I'm using Magnum 15% with a synthetic/castor mix. I broke the engine in with this stuff and have been using it with no problems. The manual says not to turn more then 11,500 RPM so I've got it turning at 10,200 max RPM on the ground. The engine runs fine in the air and I haven't had any trouble but I did have to adjust the valves finally. Anyway, after some flights I've noticed a black oily residue on the front of the plane and wing. I can't tell if this is good or bad and the fuel coming out the blow by tube underneath looks fine with no color at all. While I'm flying most of the time I fly 3/4 throttle and the engine doesn't seem over heated at all. Is this black oily residue normal?

If you've verified it's not coming from the crankcase vent, that's very good. The black residue could be coming from a loose muffler, or some other loose part, check eveything for tightness. Dark grey or black goo is usually metal dust mixed with oil.

After looking at your pictures closely, that little bit may be nothing at all, Is your field dusty, fly off grass? The oil you see on the LE of the wing will be caused by fuel spitting from the carb and maybe some leaking past the front bearing, all normal stuff there..............

Magnum fuel Has an unknown oil content. The guy refuses to divulge the oil type or percentage. It's Magnum #1 ,#2, or #3 and that's about it.

I was at Mac Hodge's Hobby shop in Andersonville, Ga a couple years ago at a fly in. Some guy had several skids of the Magnum fuel he was selling out of the back of his trailer for $12 a case. It all went like a hot cake. I didn't buy any.

rcdude7, there was another thing I forgot to mention, when I had to adjust the valves on the engine one bank was clean as a whistle and the other one had the black oily mess all over the rocker arm and under the cover too. I'm guessing that bank is the exhaust valve side with the black oily mess.
Looking at the picture of the plane you can see that oily mess is right behind the engine going up to the L.E. , there isn't any coming from the muffler on to the wing that I can tell. So maybe it's coming from the engine somewhere and getting mixed with whatever but the underside of the plane is always soaked big time from blow by.

Brown is ok, black MAY be bad. Take a close look at it. If you see tiny silvery metallic flakes in it, the engine is MUCH too lean.

Dr.1

I don't know about the magnum fuel. Sig fuel and Byrons I know for sure you can add a couple caps full of castor to it and it will mix. Some of the fuels that have a synth / castor blend are heat or chemically blended and won't mix with regular castor. Usually, that's what I do if I find some 16% on sale.

You shouldn't use a fuel containing ANY castor oil in a Saito or ,in my opinion, any other engine for that matter.

But Gen Saito specifically states not to use castor oil in the engine. He should know, he makes them !

I'm glad you stated that it was your opinion. I see tons of engines that are still running today that were made back when castor was all there was. As for the Saito, you're right ... they don't like you using castor in a lot of ringed engines.That doesn't make it illegal. I happen to like castor. I would never use an all synth blend that has the potential to flash. I care about my bearrings.

This has been discussed here before. The USA version of the Saito Manual DOES say that a blend of synthetic/castor is OK. Here is a "copy and paste" excerpt from page 3 of the Saito Small - Medium Single Cylinder Manual:

1. Fuel. For maximum protection and
loogevity of Saito engines, Saito
recommends a fuel containing 20% oil
and 10-15% nitro methane. If this blend is
not readily available, the next best
selection is a high quality 2-cycle glow
fuel, such as Hangar 9 Aero-Blend,
Omega, Cool Power, K&B, Power
Master, etc. Use of fuels composed
entirely of castor oil is not recommended.
A mix of synthetic-castor oil is acceptable
and can be found in the various fuels
described above.

If you would like to download and verify the above, go here:

http://www.horizonhobby.com/ProdInfo...der_Manual.pdf

Additionally, I understand that Europe has some synthetic lubricants that protect better than the synthetics we have available here in USA. For MY money, I plan to use at least some castor. It protects my engines better than the synthetics available here.

Wildcat puts their oil content righ on the jug as it should be.

Here in the US we don't have the super hi-tech synthetic oils that you have in Europe. We have klotz and castor. Castor is what keeps our engines from puking out thier internals and protects them from corrosion.

BTW, I've been running a castor/kltoz synth fuel in my old saito .65 and it's still running on its original bearings after several years of service. The castor turns the muffler brown, other than that, no problems.

It has been reported that Magnum is a little skimpy on total oil. If I read your post right , it sounds like your oil didn't turn black till you reset your valves. Your now getting more power and more heat. Tune for 10,000 RPM on the ground too make sure you get plenty of oil and see if oil turns light brown again.

Hi!
The black stuff can come from a lose silencer (aluminium rubbing against alu makes black residue).
Also try a larger prop like a 13x6 APC.

Castor still protects at higher temps than any synthetic oil.

blw, read quite a bit of your notes on Saito engines. I emailed Saito and they told me to tune the engine around 9000-9500 rpm on the ground and go with a bigger prop or more pitch to get the correct rpm.
Yesterday right after work I went right over to the LHS and bought some 12x8 props to try out and some Omega 15% fuel with a 30/70 castor/synthetic oil mix. I'm hoping these changes will do the trick and the engine will be OK....

I know Saito has mentioned you can use Omega 30% Heli blend with 22% synthetic oil and there are some guys at the field that say they've been using this fuel for years with no trouble. I'm just wondering is it worth it in performance over cost and longevity of the engine? Could you add castor oil to this blend?

I'm glad they responded, pywackit. You can expect something like 300 more RPMs with 30% nitro over what you would get with 15%. I always get 15% because it is available and the Saitos run fine with it. I add castor to Omega 15%. I got a quart of castor from the hobbyshop, but you can also use castor from drug stores. It costs a bit more but it works just as well.

How much castor do you add to a jug of Omega 15%?

1.28 ounces is 1% of a gallon (128ozs). I use Power Master which is 18% oil, 1/3 castor - 2/3 synth. I add four ounces of castor to every new gallon which brings the total up to approximately 21% oil.

It doesn't have to be exact. When you add four ounces of castor to a gallon you now have 132ozs of fuel, so it's off a little. You could always remove four ounces from the new gallon and replace it with the castor if you really want to get precise, but I'm not that nitpicky.

David

Dave is referring to fluid onces by volume. Measure your castor by volume. This is the best way.

A gallon of fuel contains 128 fluid onces as Dave said but jug and fuel together usually weighs right around 100 onces if you set it on a scale. So if you are going to weigh your castor just use 1 oz.

In other words, a 16 oz fuel tank only holds 12 oz of fuel. This is all due to the specific gravity of fuel being around .75 that of water.

I usually just visually do it by pouring "about that much" in by eye? It is not so critical.

I honestly never knew that! I always thought an 8 oz tank held 8 fluid ozs of fuel.

Yes, I was referring to measurements by volume, not weight.

David

Sheesh, you guys make it so hard for yourselves with those olde worlde measurement units.

It's time to make the move to metrics, fellas. Go on, you know deep down inside that they're better!

Forty five years ago I was certain that the USA would be all metric within five years. It has come a long way but it only amounts to having to know both systems in this country.

Automobiles are almost all metric now but there are many things that have never changed

A lot of the model airplane engines still have english thread sizes on the prop nuts

The world would be much more simple without the USA system of measurement as well as 60 cycle alternating current, the odd voltage levels, and the different scan rates of video displays

We have just over the last few years been making the switch to HD TV, whereas, most countries had high definition tv's from the outset. As for metric, we really should have changed over in the 60's/70's when it was being pushed, taught in schools, etc.

I would like to find a good source for metric dimensioned balsa here in the US. It's so much easier designing, drafting and scratch building using millimeters instead of 1/32" for example.

David

Rainydave,

No, most countries didn't have HD originally. The U.S. developed broadcast TV standards that was about the best for then. Other countries started their own broadcast industry years later from scratch like we did, and the technology had improved enough for them to adopt better standards at that time. It wasn't HD but it was better than ours. We were stuck with what we invented for all these years. I learned all of this while living in Europe and S. Korea. BTW, all S. Korean sockets carry both 220/50 and 110/60.

I've used both metric and standard. I've also used 10ths of inches while surveying and 10ths of a minute when flying.

I was under the impression that the UK and western Europe have always had tv's with higher resolution than ours. I know when I was living in London in '87 I could clearly notice the difference in picture quality when I first arrived. Maybe it wasn't the same as our current HD, but I'm certain there were more lines on their screens than we had. I think we have always had something like 480 vertical lines and Europe has always had 576 lines. It was a big enough difference in resolution to notice. But, I guess they never actually referred to it as HD, it was just their normal resolution.

Somewhere in my past I have used 10ths of inches. Anyway, when you're juggling several measurements in your head at one time it's a lot easier to keep track of centimeters than fractions of inches. At least it is for my brain.

David