Changing Fuel?
 

Hey all,
Just burned the last of my 20 gal of 15% Ritche's Brew and never had a problem with it. It is not readily available here in Ohio so I purchased some 15% Cool Power from AeroTech in Canton. I run two identicly set up OS160s with pipe and pump. They both ran well untill I changed the fuel. One is OK but the other went mysteriously rich. I had to turn the HSN in almost a half a turn to clean it up. This is after running 3 or 4 taks through it where it seemed to be OK. Anyone ever had a similar problem?



Thanks Again,
Rick

RE: Changing Fuel?
 

I had a problem with an OS 1.40 going rich at low throttle.  Turned out to be the rear bearing was going bad . . . Yeah, that's what I thought too!!!

RE: Changing Fuel?
 

Rick,

Every motor is different. I have several YS's and they are all close in setup, but none are identical. You could have slight pump pressure differences or anything else, also your airflow to the carbs could be slightly different. After you change fuel if you can get the needles set and the engines are happy, just run them. I'm actually more surprised that you didn't have to adjust both, than I am that you had to adjust one,

Arch

RE: Changing Fuel?
 

They both ran fine with only minor adjustments. Then all at once I started the VF3 and when we went to clear it before takeoff it wouldn't come up and was throwing some serious smoke. I turned the HSN in and it seemed to be OK.
First thing I'm going to do is change the plug. I'll put in a K&B1L.
Scott had a problem with a newly purchased plane. The oils seemed to be incompatable and created a string-like substance that gummed up the works. I was feeling around to see if anyone had a problem changing from Ritches Brew to Cool Power.

What say you?
Rick

RE: Changing Fuel?
 

Rick

Watch out on the latest batch of KB1L plugs, cause the element sticks out from where it's welded to the face of the plug. The wire portrudes so that when you go to thread it into the head it sticks out to the threaded O.D. causing difficulty threading it . I have had to dress the wire down with a small file.;)

RE: Changing Fuel?
 

Rick,

That wouldnt surprise me. There was a similar issue a few years back if you switched from Power Master to Cool Power. It really made a mess until you got the pump flushed.

Arch

RE: Changing Fuel?
 

Rick,
I used Riches Brew for a winter and spring in my OS160 before changing to Cool Power. I have ran 2 OS160's with Cool Power 15% and they both run great (OS type F plug & 17X12, 18.1X10 props). Have you checked your exhaust system, engine-header interface, header-coupling, coupling-pipe? Over the past 3 years the only time ihave had to adjust the needle setting was because of a leak somewhere in the exhaust system.

Glen

RE: Changing Fuel?
 

Thanks Guys.
Looking for all your thoughts and experiences. It gives me lots of things to look at. All your thoughts and experiences are greatly appreciated!
Rick

RE: Changing Fuel?
 

I had a similar experience when switching from Ritch's Brew to Cool Power. A buddy of mine says it is the difference in the way the two companies mix their fuels. If I'm remembering correctly I think he said Ritch's Brew mixes by volume and cool power mixes by weight. Not positive on that, so don't quote me. Either way, it's apparently normal.

RE: Changing Fuel?
 

My Brio acted up the same way last night. I had flown it with the CoolPower for probably 20 flights then all at once I had to lean it 4 clicks to get it to run right.
With different specific gravities, volume and weight will yeild different actual amounts of ingredients. MEOH(methanol) has a specific gravity of .8. Nitromethane has a specific gravity of 1.139 meanig that by volume it will actually give you more nitro in your fuel. I understand that you will have to change needles with nitro changes but I am puzzled why after the original adjustments after the fuel change, both set ups suddenly went blubbering rich.

Thanks for all the input people.
RC