Bad Brodak 5/29 fuel?
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Bad Brodak 5/29 fuel?
Someone gave me a quart of Brodak's 5/29 fuel a while ago and it runs horribly in 3 different Fox Stunt .35's I've tried it in. It seems plenty oily, but they behave like the nitro content is below the claimed 5%. The engines behave like its a straight alcohol/oil fuel.
I've tried Stunt .35's on 75/25 FAI fuel and they behaved just like this stuff. Kinda hard to start, super critical needle setting, significant power loss.
The stuff smell like there's a touch of nitro in there, but it can't be right...
I've tried Stunt .35's on 75/25 FAI fuel and they behaved just like this stuff. Kinda hard to start, super critical needle setting, significant power loss.
The stuff smell like there's a touch of nitro in there, but it can't be right...
#3
RE: Bad Brodak 5/29 fuel?
Sound like the can hasn't been sealed tight, methanol evaporated and some humidity (from the air)got into the rest. The % of oil get higher as the methanol evaporate.
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RE: Bad Brodak 5/29 fuel?
Na, it was capped tight and unopened until recently, and the volume was to the top, so nothing significance evaporated.
#5
RE: Bad Brodak 5/29 fuel?
ORIGINAL: cutaway
I've tried Stunt .35's on 75/25 FAI fuel and they behaved just like this stuff. Kinda hard to start, super critical needle setting, significant power loss.
I've tried Stunt .35's on 75/25 FAI fuel and they behaved just like this stuff. Kinda hard to start, super critical needle setting, significant power loss.
#6
RE: Bad Brodak 5/29 fuel?
Weak glow plugs? I know unlikely on three engines, but possible. High humidity in the air could also be an issue.
I don't know what needle you are using, but the old stock Fox was not very precise. The new ones should be great, no detents so you can get really fine.
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RE: Bad Brodak 5/29 fuel?
ORIGINAL: cutaway
I've tried Stunt .35's on 75/25 FAI fuel and they behaved just like this stuff. Kinda hard to start, super critical needle setting, significant power loss.
I've tried Stunt .35's on 75/25 FAI fuel and they behaved just like this stuff. Kinda hard to start, super critical needle setting, significant power loss.
No starting o behavior issues of any sort , almost every engine started first flick with usually a generous prime both in the carb and the exhaust. When mufflers became a norm, only carb prime ...sure when I tried 5% nitro needle settings became way more consistent ( I even used to cut a slot in the cowl to detach the engine without disturbing the needle for not to loose that "magic" setting found ). No particular power gain over straight fuel, as far 5% nitro. Maybe with more....
Also the we always used the original FOX needle ( even if whe had lot of cheap Supertigre needle valve assemblies ) because, once used to the strange one click=lean-two click=rich behavior, no problems of any sort.
When the fashion was toward ST 46, whe had a hard time to find again that FOX built in stunt friendlyness ( 4-2-4 etc .... )
I think your fuel is good to be presented to your closest competitor ( or...maybe actual FOXes are not the same as before, who knows...)
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RE: Bad Brodak 5/29 fuel?
Cutaway, do you have some known good fuel for comparison, or is the gift fuel all you have to run in these motors? I'd try to get some fresh Powermaster GMA 10/29 at the LHS. If they don't have that (and most don't), get some Wildcat Premium Extra 10% nitro (18% total lube) and amplify it with castor oil to 28-29% total lube. To do this, put 4 oz of castor oil in a quart container and fill it with the Wildcat Premium Extra fuel. That'll give you 28.25% total lube, which is sufficient for the Fox. Try it and see how it compares. If that fixes the problem, you know what to do round file the bad fuel. If not, then at least try a fresh hot glow plug in the motor just to eliminate this variable.
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RE: Bad Brodak 5/29 fuel?
ORIGINAL: chuckiezback
Cutaway, do you have some known good fuel for comparison...
Cutaway, do you have some known good fuel for comparison...