slammin_sam

I've got a Fox 46 BB on an uproar and flew it for the first time today. The Fox only has about 30 minutes on it. It seems a little touchy when tuning. I have to increase throttle slowly or it hesitates. Any experience out there that might help?

Hobbsy

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The Fox .46 is normally one the best engines around, it should turn a 10x6 above 14,000, I prefer to run an 11x6 on mine, It sounds like your airbleed needs opened up a little or the top end is a little rich. A Fox Gold post standard or Gold Post idle bar runs best in these. I had two .46s but changed one to a .50 so I could put a Davis head on it. I believe the .50 is the lightest .40 sized engine there is. Even lighter than my Webra .50. But it sounds like a tweak on the idle air or main needle is all you need if it isn't the plug.

slammin_sam

Thanks Hobbsy. I tweaked the low end a little and it is running great. I'm running a 11X6 on it. Lot's of power. The more I run it the better it gets. What Idle bar does it come with? Do you have any suggestions on a tuned pipe? Thanks again!

jmupilot

I too have a Fox 46 BB and it is having the same problems. I have tweaked the low end air bleed needle til i'm blue in the face and no improvement. It runs great at high speed and if throttle is transitioned from low to high slowly its fine. but let the thing idle for a few minutes and it loads up and quits. It's brand new and has about 20 oz of fuel thru it now. I have 2 of the older 45BB snd even tried on of those carbs on it it ran fine then. I know the air bleed is very sensitive and a little goes along way but i cant seem to hit the right combo. I've got an APC 11x5 prop on it. It will idle reliably at 3000 for a long time and the high end hits 13000, but it just wont go from low to high. any suggestions. to fix this?

Pete

3D Romeo

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jmupilot

I'm no expert where Fox engines are concerned. As a matter of fact, I have a NIB Fox .46 sitting on my bench right now that I'm trying to decide whether to sell, or keep?

...But one thing everyone at my club that uses Fox engines tells me is, they need to be broken in before you start to realize the benefits of these engines. With only 20 oz. of fuel through yours, it is still basically new.

That's one reason I'm debating whether to sell mine right now. I need an engine for one of my 3D planes, and I don't know if I want to mess around with the sensitive tuning, and longer than usual break-in procedure that the Fox engines seem to require. I'm wondering whether to just get an OS .46FX and hover out of the box?

Any Comments?

jmupilot

Yes I've heard that Fox Motors do need to be broke in. I have 2 45 BB that are at least 20 years old. They are well broken in and run great, but have the old style carbs, both turn 10/6 APC's in excess of 14,000 rpm. I acquired one of them from a person that could not get his Fox to run, and said, "if you think you can get it to run then here have fun". He gave it to me. Its been running fine ever since. I have 4 or 5 more Fox motors that are from the 70's and they run great. I just am having problems with this new 46 BB. I have ordered a Perry Carb and adapter to try that route. I have perry carbs on some of my other R/C engines and they have solved finicky carb problems i've had with them. I'm about at wits end with this new 46 BB. Just running fuel thru it to break it in is nuts. I think I'll put it on a plane that doesn't need a lot of power to fly and run it rich and at least break it in as i fly.


Pete

3D Romeo

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Pete,

The problem you are having is the exact reason I'm thinking of selling my .46 while it is still NIB.

When you are into 3D flying, I don't know if I can sit back and wait for an engine to break-in. Sure it may be a good and powerful engine, but I don't know if I want to take the chance when I know of several other engines that will perform great right out of the box. Granted, they cost a bit more. But when you are hovering at a couple inches from the ground, I want to be sure the engine will respond if called upon, and not have to second guess if the engine is broke-in enough to do this.

Good luck with your problem...I still need to do some thinking.

slammin_sam

I've got another hour on the Fox since I started this thread and it's running great now. I think it's worth waiting for but if I wanted something almost ready to go out of the box I'd go with the TT 46 and a tower muffler.

3D Romeo

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slammin_sam

I agree exactly with what you said...which is why I originally bought the Fox in the first place.

But for the way I fly now I kinda' want that 'out of the box' performance and reliability.

I'm also leaning toward your recommendation of the TT .46 Pro, as well. I was almost 100% sure my next .46 size engine would be the OS .46FX. But after reading through dozens of threads since my last post here, I'm amazed at how many times the TT .46 Pro came up as peoples favorite engine! I've never really heard anything bad about the OS .46FX (except price)...but I really haven't heard anything bad about the TT .46 Pro either, and it costs much less.

Thanks for the reply Sam!

Sport_Pilot

IMO I don't see what is so hard about clamping an engine to a test bench and runing a half dozen tanks of fuel through it. After the first couple of tanks or so, you don't have to stand over it constantly.

3D Romeo

My Feedback: (111)

Sport_Pilot

I appreciate the comments, and standing over an engine may be fine for some people...

...But I would rather have half a dozen flights, than half a dozen watching an engine breaking-ins.

I'm not disagreeing that the Fox is a good engine. I just would rather fly NOW!


The engine will be going up for sale soon, most likely...so if you want to buy a NIB Fox .46 BB before I post it on RCU, I'll let you have it for $80 (NIB).

Thank You!

Sport_Pilot

The point I was trying to make, after I can be sure the engine will run continously without overheating, I DON'T STAND OVER IT AND WATCH. I am usually near by inside the garage working on models, or the car. While the engine is running outside on a small bench wighted down with bricks.

3D Romeo

My Feedback: (111)

Sport_Pilot

I understood what you meant...but obviously you didn't understand what I meant.

Whether you are standing over it, standing under it, standing on top of it, or even working in your garage while it runs. I agreed that this may be fine for some people. But for ME, I would rather be FLYING!

Guess what, while you were inside your garage working on your car...I was flying. While you were in your garage working on your airplane...I was flying. I fly whenever weather permits, and if the weather is to bad to fly, it is probably to bad for me to run a motor outside, as well.

Also, your very description of your engine is the exact thing that scared me away from them in the first place.

"after I can be sure the engine will run continuously without overheating"

"While the engine is running outside on a small bench"

I have several other engines, by other manufacturer's, that I could trust right out of the box, to idle, not over-heat, and give very good power.

But once again, please understand me when I say this...I am in no way knocking Fox engines. After all, I bought the engine because at the time I wanted a powerful, and good running engine. But things change, and now I want to FLY right NOW. I don't want to go through the lengthy break-in that Fox & Enya engines (another fine engine once broken-in) seem to require.

Another thing that has turned me off a little about Fox engines, after reading through countless threads on people that had problems with theirs, they are always told by Fox to use Fox fuel. That's not bad if you only run Fox engines...but I don't want to be inconvenienced by having to stock, and bring to the flying field, two different kinds of fuels.

Let me close by just saying...You know what you want, and I know what I want...and anybody that wants to buy a NIB Fox .46 BB or a NIB Fox 15 BB please let me know.

Thank You...and sorry for getting a little lengthy with my post.

...and once again...Fox is a great engine...just not for me right now.

zx32tt

My Feedback: (9)

I've had a Fox 46 for several years, and its likley got at least 5 gal. of fuel thru it. I too was about ready to chunk it for something more reliable. I happend onto a website that caters to Fox owners of all sizes. One of their suggestions was to swith to a Fox Wonderplug. It worked. Fox engines (mine anyhow) are pretty tight from the factory. They need a little bench running, and they like a higher castor content in the fuel. Hope this helps.
If all else fails, e-mail me with your price, we can talk.
ProBro #229

zx32tt

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Here is the Fox web link http://www3.bc.sympatico.ca/fliteline/

3D Romeo

My Feedback: (111)

Hi,

I noticed that you might be interested in my NIB Fox .46 BB?

Like I eluded to in my posts, I've heard many good things about this engine, and I know they are right up there with the most powerful engines in this size range. I just don't want to wait for it to break-in, or have to keep 2 fuel mixtures on hand. The glow plugs wouldn't have been a problem though, since I use Fox plugs in all of my engines right now.

Anyway, I'm asking $80 for the engine. I'm just looking for a good down payment on the engine that I plan to replace it with. I just checked Fox's web site, too, and they are selling it for $186.95 + Shipping! (http://www.foxmanufacturing.com/stor...Motors%20R%2FC) I would have set the price higher...but I already said I'd sell it for $80 a couple posts ago.

I also have a NIB Fox .15 BB that I got for combat...but since I don't fly combat anymore, I won't be needing it either. Fox says it is the most powerful .15 out there! I wouldn't know...I never ran it.

Well, what do you think?

Mark

3D Romeo

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Sorry for my last post...it was meant to be a PM. But I accidentally hit the 'Reply' button instead.

slammin_sam

This is getting old. I seem to be back to square one. I was idling along for 30 seconds or so to start to bring it in, hit the throttle and had an instant stop. I was lucky to get it back to the field and had a very hard landing. I thought I had it tuned pretty well unless the tuning changes as it continues to break in. Someone had mentioned a dif idle bar earlier. How about a little more info on that???

Woody 51

Sam, contact the guys at http://www3.bc.sympatico.ca/fliteline/

This site has been mentioned before in this thread.

They helped me fix my .74R. which was a dog. Now it's a great runner.

Fox changed the .46 casting internally, that makes it prone to sucking in air via the front bearing!!! (Result- engine quits)

The above mentioned site explains what to look for and how to fix it.

Also, have you considered the new Fox Twin Needle Carb for your .46? It makes for more reliable running as well when compared to the air bleed carby. The website will have details and part numbers etc.

I also have a Fox .45R. It is extremely reliable, has been since 1st start. Not the most powerful engine around, but in a semi scale PT19, it's perfect.

ArthurR

Fox has had many problems with improperly drilled high speed and low speed needle valve seats. They are sometimes drilled too deeply due to poor quality control. They know it but continue to ship defective engines. I have five Fox engines and four of them had the problems you mentioned. Calling Fox and describing your problem will usually get them to send you a new carb. Don't listen to the line "You're the first one to complain about that."

A good fix is to buy a OS 50SX with an Ultra Thrust muffler from Performance Specialities and sell the Fox to someone who like them.

Sport_Pilot

Since the needle simply goes into the spray bar there is not a seat, so nothing that they can drill too deep! Fox has on some engines sent needle which have a steep taper, and some of the instuctions show how to file the needles to get the proper midrange. Unfortunately a lot of second hand engines are sold without doing this and without the instructions.

ArthurR

Sport,
Poor quality control of the drilling operation for the needle valves was told to me by Charlie at Fox motors as the reason for inability to properly adjust carbs on some new Fox engines. He manages the company since Mrs. Fox passed away, so I assumed he knew what he's talking about. He knew exactly how to correct the problem and was ahead of me as I described it to him. The replacment parts he sent solved the problem.