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ORIGINAL: earlwb

No discounts or anything. I bought the carbs over a long period of time. One or two at a time. Usually when I ordered some other stuff.
Sorry no factory sponsorships for me. I wish.

Of course the new Fox carb works good on other brands of engines too.

quote:

ORIGINAL: earlwb

It is on a .61 engine. The original OEM carb worked OK but it was too rich for my liking through the mid-range. So the Fox carb was a nice improvement for it.

quote:

ORIGINAL: earlwb

The Fox .45, .50,  .60 and .74 engines all use the same flange mount carb. They do not make a round base carb that can be  inserted into the engine type of carb in this size range. The small frame .40 engines use a square base carb for inserting into a square hole in the engine crankcase (an adaptation from the Fox .36 combat engine days). What I did was make an adapter for the Fox carb to insert into a hole like shown in the pic above.

Oh yeah the carb has approximately an 8mm venturi bore to it  ( about 0.300 inches).

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ORIGINAL: 1QwkSport2.5r

quote:

ORIGINAL: earlwb

The Fox .45, .50,  .60 and .74 engines all use the same flange mount carb. They do not make a round base carb that can be  inserted into the engine type of carb in this size range. The small frame .40 engines use a square base carb for inserting into a square hole in the engine crankcase (an adaptation from the Fox .36 combat engine days). What I did was make an adapter for the Fox carb to insert into a hole like shown in the pic above.

Oh yeah the carb has approximately an 8mm venturi bore to it  ( about 0.300 inches).

I thought Fox had a round neck carburetor these days... I stand corrected. I may have to source an ASP 108 carb, or get one from Dub. I'd rather have one of Dub's carbs though.

Hopefully next year I'll have some spare money to turn in my twice killed Fox .40 small case in exchange for a Fox .60.

Thanks for sharing the info, Earl. I'll keep looking...

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ORIGINAL: 1QwkSport2.5r

HSukaria - I am not ultra fond of the idea of using a ''cheap'' carb, but I'm not totally opposed to it. I am in the market for a good 2-needle carb that works well and has a larger Venturi than stock. The ASP 108 carb is said to add 1000rpm, and a good tuner muffler/MCP will add another 1000rpm. We'll see how far I actually get on this.

My buddy needs stuff from HP/HK so I might tack a carb on his order to combine shipping.

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ORIGINAL: hsukaria

quote:

ORIGINAL: 1QwkSport2.5r

HSukaria - I am not ultra fond of the idea of using a ''cheap'' carb, but I'm not totally opposed to it. I am in the market for a good 2-needle carb that works well and has a larger Venturi than stock. The ASP 108 carb is said to add 1000rpm, and a good tuner muffler/MCP will add another 1000rpm. We'll see how far I actually get on this.

My buddy needs stuff from HP/HK so I might tack a carb on his order to combine shipping.

Sounds interesting. I wonder how the throttle response and tank pressurization will be with a big venturi.

I was just cracking up because your two choices included the cheapest and (possibly) one of the most expensive carbs out there.

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ORIGINAL: 1QwkSport2.5r

quote:

ORIGINAL: hsukaria

quote:

ORIGINAL: 1QwkSport2.5r

HSukaria - I am not ultra fond of the idea of using a ''cheap'' carb, but I'm not totally opposed to it. I am in the market for a good 2-needle carb that works well and has a larger Venturi than stock. The ASP 108 carb is said to add 1000rpm, and a good tuner muffler/MCP will add another 1000rpm. We'll see how far I actually get on this.

My buddy needs stuff from HP/HK so I might tack a carb on his order to combine shipping.

Sounds interesting. I wonder how the throttle response and tank pressurization will be with a big venturi.

I was just cracking up because your two choices included the cheapest and (possibly) one of the most expensive carbs out there.

Well, an OS 7D fits the ST 90 but they're very hard to find and expensive, possibly more costly than a Jett carb. The reason I'd lean towards the 7D or Jett carb is A) they're proven to work well and B) the .590'' neck size is common among many engines so it could be used on more than one engine. I know the quality is hit and miss with Magnum/ASP in the carb department so I'm a little leary of that. (I would prefer to support US companies if possible, another reason for thinking Fox or Jett). The crankshaft has a pretty healthy sized hole (I forget the exact size) that is a good bit larger than the carb throat. So I'm not real concerned with fuel draw. If I went to a 12mm or larger carb then I can see a problem arising.

Anyway, this was an idea I've kicked around for awhile. Not sure ill do anything just yet.

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ORIGINAL: 1QwkSport2.5r

I kinda figured. I will look into it when I'm off work.

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ORIGINAL: hsukaria

quote:

ORIGINAL: 1QwkSport2.5r

I kinda figured. I will look into it when I'm off work.

while you're at it, check out their dirt-cheap glow plugs. I wonder if they are any good. Has anybody tested the HK plugs?

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ORIGINAL: turbo.gst

I find the Perry section at Conley Precision to be a wealth of carb sizing info while indicating compatibilty between engine makes. I have tried just about every engine / carb combination in my stable. I am fortunate to have a huge collection to use for reference. I do the same with compatible mufflers. Sometimes the results are very rewarding.

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ORIGINAL: turbo.gst

I find the Perry section at Conley Precision to be a wealth of carb sizing info while indicating compatibilty between engine makes. I have tried just about every engine / carb combination in my stable. I am fortunate to have a huge collection to use for reference. I do the same with compatible mufflers. Sometimes the results are very rewarding.

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ORIGINAL: hsukaria

I finally got to read part of the owner's manual for my Fox 74 online. One interesting trick it mentions is to tune the HSN for max power while the glow starter is connected, then noting if the rpms drop after removing the glow starter. The manual states that if the rpms drop after removing the starter, that indicates that the fuel needs more nitro.

Maybe you guys knew that, but I guess I shoulda read the manual.

Another interesting fact in the manual is that it claims that the 74 can turn a 14x6 prop. I tried a 13x6 before, but I had other issues to work out with the engine. I will try to do some more tuning to see how big a prop I can run. I like bigger props on my planes up to a point. I am running 12x6 now, but would like to go back to 13x6 later on.

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ORIGINAL: hsukaria

quote:

ORIGINAL: turbo.gst

I find the Perry section at Conley Precision to be a wealth of carb sizing info while indicating compatibilty between engine makes. I have tried just about every engine / carb combination in my stable. I am fortunate to have a huge collection to use for reference. I do the same with compatible mufflers. Sometimes the results are very rewarding.

Thanks for the link, Turbo. I looked at the site and based on what 1QwkSport2.5r is looking for, he will need to use a pump carb with a Perry pump. The size of venturi he is looking for is around 9.5 - 10mm, which only comes as a pump carb.

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ORIGINAL: 1QwkSport2.5r

Typically, I run 5% nitro 20% castor in most of my engines. I run 25% castor in my lapped iron/steel engines, and my bushed crankshaft engines. Nitro is expensive, so I try to use as little as possible. I've noted a 500-800rpm loss when running FAI fuel (true 80/20) even with some acetone in it, so I went back to 5%. I have tried higher nitro in my Enya 4-stroke .60, but it didnt run any faster or better with more nitro so I went back to my normal mix. I have been mixing my own fuel for two years now because a gallon of glow fuel costs me at minimum $32. My car fuel with 20% nitro and 12% oil is about $37 a gallon. Mixing my own, fuel costs me between $8 and $12 a gallon. I think I burned 6-7 gallons of fuel this year (about half of that was breaking in engines.. )

I went out to run the G51 some more, trying to get a picture of the carb ''spitting'', but none of my pictures captured the spitting fuel like Earl was able to capture. I was using a 1600 ISO setting as well.

Hsukaria - before I ran out of light for my tach to work, I ran a 10x6 APC on the little G51 and got 14,460rpm on 5% nitro 20% oil at 50/50 blend of castor/synthetic. (using up some experimental fuel). I also tried an 11x9 and 11x6 but it seemed overpropped with both of these props. The needle had to be very rich on the top, but transition ended up being pretty rich. I also tried the Fox method for setting the needle, and I lost almost 1000rpm when I removed the glow driver. The plug I was using was the same plug I broke the engine in on, which was used and abused to start with. I think it is a medium or medium/hot plug; not my normal hot plug that I usually use. Tomorrow, pending the rainstorm, I will try again with a new plug and my normal 20% castor fuel and run a few props.