A65 Mixture control

[8708]

I am overhauling my A65 now and am wondering why there is no mixture control. Is it just not needed for an engine this size or?

[mulwyk]

Re: A65 Mixture control

Folks that have a functioning mixture on the A65 report that it doesn't do anything. So you'll usually find either a non-mixture-control carb or one with the mixture wired in the full rich position.

Bob Gustafson

[Ragwing nut]

Re: A65 Mixture control

Believe it or not, it is almost what was considered an option. It is not needed, but makes life easier if you do any high flying or for those 100* days where 1500 ft field elevations can reach 4-5000 ft due to the temp. First determine what carb you have. If it is a NAS-3B, it doesn't have any mixture parts in it unless it has been added. If it is a NAS-3A1, it may just be saftied full rich like many were and all you will need to do is add a cable. Look for a very short horizontal arm above the fuel bowl.

Mike

[VictorBravo]

Re: A65 Mixture control

I agree it is probably a marginal improvement to have the mixture. But then again, everything can be marginal on a 65 powered airplane. Another 3 or 4 actual horsepower to the propeller under many circumstances can be a big deal. I hooked mine up. I can get another 25 RPM in cruise at 5000 feet. Probably reduces plug fouling anyway.

[taylorcraftbc65]

Re: A65 Mixture control

Guys,
I have a mixture control on "Manu Sina", and at 4,500' and 95 degrees Temp, it DOES make a difference. I don't think it makes a ton of difference, but the engine does not seem to load up at all as I slide the throttle to the firewall on takeoff, and the plugs are real clean. Before I removed the wire holding the lever full rich, the plugs were very carbon fouled. Brie

[8708]

Re: A65 Mixture control

What a great forum! Thanks for the information. I will see what model of carb I have. I live at 3000 ft elevation and we get hot in the summer so it sounds like it would be good to have.
Thanks again!
Jay

[Mark Julicher]

Re: A65 Mixture control

I have a functioning mixture control and it will raise the EGT by 175 degrees at a cruise power setting of 2150 RPM and 3000 ft altitude.

This saves about $4.73 a year in avgas at the rate I have been flying. I think I better go roll one and get high

FWIW, a package of wintergreen Lifesavers will make your plane smell the same as MMO, but it it won't run quite right. Now THERE is information you won't find on the Aeronca forum

[Vasey fan]

Re: A65 Mixture control

I've got a Stromberg with functioning mixture control on my C-85, it works. It really doesn't do a lot below 5000', but my home field elevation IS 5000'.

I usually do a full power run up to check static RPM, if it looks good I don't lean, during the summer I end up leaning it just about every time. At 10,000' on up I can cruise with the throttle wide open @ about 2450 rpm (cruise prop) with the mixture way back, fuel consumption is usually 5 gph or less.

[srf471]

Re: A65 Mixture control

When I bought my plane (C85-12) the mixture was wired full rich. The seller told me he did that with all of his C85's because the mixture is so sensitive that it is very easy to accidentally kill the engine when leaning.

Any truth to this?

BTW, I live in South Florida at sea level. Even on the hottest of summer days we might reach 2,500' density. But, later this spring I hope to fly it up to our cabin in the North Ga mountains where the airport is at 2000' and the mountains are 3,000 to 5,000' high

Nick TOF#695

[NY86]

Re: A65 Mixture control

Yes, that's the main reason they get wired. If you pull it out quickly, especially at low altitudes, you can go from "no change" to "no noise" in short order. Scares the heck out of student pilots! It doesn't work the same way as a Marvel. The trick is to pull it a little at a time and wait to see if there is any effect. If you don't get any RPM increase, then it's not doing any good and you might as well leave it in all the way.