Matt Kirsch

My Feedback: (21)

Send me your so-called "doorstop" Tower Hobbies .46 engines. I'd offer money, but then we'd have to take this discussion over to the marketplace

taildragger101

My Feedback: (2)

One other thing no one has said, I had the same prob with my 46 on my profile , nose high and it starved for fuel. Found out minimal muff preasure. Had a rubber extension on the outlet and took a tiestrap and put the sqeeze to it. Runs like a dream. Try this before you use it as a paper weight

JimRoss

Naw, just box it up and send it to Jim Ross, he knows how to make 'em run.
After all, a paperweight won't fly anything.

William Robison

My Feedback: (3)

All right!

We have one who will take the doorstops, another who wants the paperweights. Now all the rest of you can send me the trash bag fillers.

Haw.

Bill.

jsevey

This may be way over-simplified- but I recently deadsticked my Kadet MkII on 3 successive flights within 30 seconds of taking off. Out of frustration, I packed up and headed home. The fuel line was empty so I figured I had a major leak somewhere. I have limited storage at my house and hang my planes nose down for storage. I hung the plane for a week and the following weekend I brought the MKII out to the garage. I pulled the tank and saw that the klunk had bent the fuel line down and was leaning against the front of the tank and hung up on the top side of the supply line. When I go flying now, I always check the klunk before I even put on the wing or fill the tank. 25 flights later- no more flameouts. I did get some good experience turning the plane around deadstick right after takeoff and landing, but I'd rather not have to do that anymore.

Just a thought.

Prop Nut

My Feedback: (3)

Here is another thought, my only one for the day......so dont waste it. I read in the AMA mag about others having this trouble. Seems the screw holding the two halves of the muffler together (Dont know myself if the tower has a two piece muffler, I use OS, they always work......no..........no......dont flame me!!!) comes loose and in flight the higher rpm causes the back pressure loss to kill the engine. I believe the artical is in the December issue, not real sure as it is in the reading place and I am in the office. Its winter here and I am to lazy to walk to the bathroom and fetch it. But, if anyone wants more info on this I guess I could be talked into it. No telling when I would get back out of there though, have several new model magazines I havent yet purused.

DiscoWings

My Feedback: (76)

my tower hobbies sucks as well, I even did warranty replacement on it... man I'm not paying another 7.99 to ship to tower just to get another retarded 46[]
We should all get together and sue tower for making such horrible engines.

dwaynenancy

My Feedback: (62)

Send me your tired and poor. Dwayne in Amarillo

Gravityisnotmyfriend

My Feedback: (2)

I have two tower engines. One, that I bought new, runs like a champ - makes tons of power. After its warmed up, it will start with one or two flips of the prop. The other one, which was given to me, has never run right (that's why it was given to me). If I tune it for WOT it makes monster power, but won't idle. If I tune for idle, it dies in the mid-range. But, after reading Bax's post, I'm flabberghasted. I've been reading all I can about engine tuning. As someone else said, it does appear to be a black art. From what I understood, you always tune the low speed first, then the high speed. I thought that the low speed settiing affected the high speed, but not the other way around and that's why you adjusted the low speed first. I also thought that I was well informed that these engines leak around the front bearing. I presently have my poor running engine dismantled with the intention of replacing the front bearing. I did a search to find more info and came across this thread. I guess I'll put it back together and see what I can do. If I can get this one to run like my other one, I'll be a very happy guy.

Gravityisnotmyfriend

My Feedback: (2)

Just a quick update. I put the engine back together and I compared the gap between idle needle and fuel nozzzle to the engine that runs good. I guesstimate (I don't have a feeler gauge that will fit in the carb) that the good running engine has about a 1.5mm gap. Then I looked at the poor running engine. Guess what - no gap! I'm amazed that the thing ran at all. I'm looking forward to putting it on the test stand and see what it'll do. Bax, thanks for the info. I'll post how it turns out.

dasflugmodele

Perhaps I should have left the tower 46 I have at the yard sale. Its new never run but I need mfg. instructions for it. With all you folks throwing them out someone must have a copy of the instructions I could beg,borrow or comshaw. Hate to ruin a perfectly new 46 by not following the mfg. rules.
das

Prop Nut

My Feedback: (3)

They come with Instructions? What are these instructions things? Do you get them with everything? kidding

RC-Captain

Although You didnt provide enough information this is what I came up with from the tower web site.

Factory Settings:
High speed: 1-1/2 turns out
Low end: 2mm gap
Idle speed: N/A- adjusted through throttle

Once you set the needle , then do your up and down test with the airplane . be very careful people are just cutting themselves up now a days witht he prop.

mrfx2001

My Feedback: (2)

What's with that..full moon lunar year...one of the guys had the nerve to chop off the end of his thumb and then bleed all over the interior of my car as I carried him to the hospital.

mrfx2001

My Feedback: (2)

Gentlemen,
Here are some thoughts I had on the subject and thought I’d pass them on. Every field has an engine guy or two and I’m one.
I am an old nitro boat racer from the 60’s, 70’, and 80’s. I have two of these tower 46’s and some MECOA’s and GMS’s and they all exhibit these symptoms. (Seems to be all of the Chinese \ American knockoffs of the OS 46). Oh yes, I run OS too. The problem has been hit on a bunch of times in this thread. Engine leaning, then thermal runaway. The engine goes lean for what ever the reason and then the hotter the engine gets the less the fuel draw. I went through my engines and found that if you have a machinist friend and get a carb adaptor for an OS carb made, then mount a OS carb the problem goes away. (I had some OS 4D carbs from the OS 46 marine engines lying around.) The OS carb seems to be superior to the original part. Yes, I know, this is not a practical solution to the delema. The problem is one of fuel draw, tank pressure, and engine temp. If you keep the engine temp in check the manifold vacuum will remain constant for a given throttle setting given proper tank placement. (The aircraft will not “G� out lean in a maneuver.) If you have proper tank pressure for the range of throttle response the engine will not lean out. If the tank is mounted in line with the spray bar the effects of tank position relative to the engine is minimized. (ALL IN A PERFECT WORLD) Another item that just came to mind that has not been mentioned is fuel foaming.
All of the above have fixes and the price is the main factor. (At least in my case)
One at a time…..
1.) Fuel foaming. So you say…… I don’t see any bubbles while it is running. Stop the engine and let it set for a short time. Thump the fuel tubing with your finger and see if some bubbles appear from a fitting or barb. With the engines running at the rev/s they do, vibrations are sufficient to homogenize the air with the fuel. (Yep it’s a big word, look it up….I had to.) In a simpler form, the air might be there, you can’t see it, and it may only happen when airborne. An easy fix is to contaminate your fuel with Teflon. (Reduce the friction between the molecules.) I do it all the time with no problems. 2 to3 drops of ARMOR ALL per gallon. Helps in Combat. Next, get rid of the AIR. Run a BLADDER TANK. Expensive but effective.

2.) Engine temperature…….. I harp at the field about this one the most. Anyone that thinks they can break in an engine on a aircraft in flight has lost there mind, unless they are a seasoned pilot able to handle a dead stick landing from any quadrant of the field and has enough sense to grab all the altitude necessary during takeoff, just in case. Take some lessons from combat pilots. Every landing is dead-stick (for the most part). If the airplane has a cowl you don’t have a chance to control the engine temperature. (DOOMED FROM THE GET-GO.) Break in is a process of the parts wearing to a running tolerance at which time the engine will not have a tendency to overheat due to the parts being tight. (Remember the post that said the engine that was replaced felt like it had good compression.) If the engine is tight for the fuel and prop setup, it will overheat. Recommendation…Break-in on a bench so you can measure the temperature and easily control throttle and mixture until you have reliable run-up and idle. You might just save yourself from a botched approach to the runway. (Unless you’re good.)

3.) Fuel Draw……….Here is the Tough one. Generally the builder has a lot of restraints in the model as to where the tank can be placed. If the engine is an old faithful friend the placement is not critical. If the engine shows a tendency to run hot there are a few things to consider. Is the tank center in the center line of the engine spray bar? Get it as close as you can. Increase the exhaust back pressure by restricting the pipe opening. (Till the engine breaks-in.) And the one I like the most is to install a supply on demand fuel system. This system allows the builder to put the tanks anywhere in the aircraft. Yes it’s a little pricey, but how much is avoiding a botched dead stick landing worth?
Ref:
http://www.billsroom.com/pcfs/produc...uelsysdesc.htm
http://www.ironbaymodelcompany.com/W...Regulator.html
Hope this helps. Works good for me.
mrfx2001

CRAPTECH

I thought that I was going mad. I have gotten back into RC after about a 12 year absent. So I wanted to get all new gear to retrain myself. I got ugly stick and a Tower .46. All my friends and I cannot get that thing to run in the air. We have tried almost everything. I just run it wide open and a little rich just to fly. So I called tower to see if there was something I was missing. I could not talk directly to a tech person. So I got a 20 year old, gummed up super tiger 40, put it on the plane, using the same fuel tank, same fuel lines, same prop and spinner, same plug. After about 1/8 of tank it started running very good. No problems... Had to be something in the Tower 46.
So I took the super tiger crab put it in a drill and turned down the base to fit the tower 46. Put the tower 46 back in the plane. It runs great. Next I started looking at the tower 46 crab, that is the problem, the motor is a great little motor, just a bad crab design,
If you look at super tiger or OS crabs you will see a spray bar, this DRAWS fuel. The ST and OS motors have a tapered low-end needle.
The tower motor does not really have a spray bar it just has a flat tube type thing and the low end is a type of plug that closed off the plug of idle. I suppose that you can get the stock Tower 46 to run if you put the tank high enough so fuel draw is not an issue. I thing you get what you pay for. Pay the extra and get a motor that will last a long time and run right out of the box..[]

NM2K

My Feedback: (14)

---------------------


Rick, you have to understand that model engines will run, even with the carburetor off.

Don't believe me?

Try this:

If your engine is mounted in a test stand or your model, do the following.

Make sure that your booster battery is fully charged. This is the battery that provides power to your glow plug during starting. A fully charged nicad battery will provide sufficient voltage to start your engine, IF it is fully charged. Carbon zinc flashlight batteries can also be used.

Remove the carb.

Pull the glow plug now and ensure that it will glow brightly with power applied. If it doesn't light up, your engine will not start. It is your responsibility to ensure that the mechanism used to conduct power through the glow plug works effectively - not the engine manufacturer.

Reinstall your working glow plug, or install a fresh, working glow plug.

Put three or four drops of fuel into the slot of the exposed crankshaft, right under where the carb was positioned. You may have to turn the propeller to find the open slot in the crankshaft.

Flip the prop four or five times, to distribute the fuel droplets throughout the engine's internal passages. This is without booster power applied.

Apply voltage to the proper, working, glow plug that is installed in your engine. One side of the battery connection goes to the center post of the glow plug. The other side of the battery connection goes to any place on the crankcase, or the glow plug body.

Smartly flip the propeller through TDC (top dead center), ensuring that your chicken stick is adequately out of the way in case the engine starts, which it will. DO NOT flip the engine's propeller with your fingers. Regardless of how quick you are, eventually you will injure your fingers if you use them to flip the propeller.

If all of the above steps were carried out as I "think" I have written them, your engine WILL start - even without a carburetor mounted.

------------------------

So what was the point of all of this? The point is to demonstrate to you that carb needle position or quality has nothing to do with starting your engine. The engine requires that certain criteria be met in order to start. If these criteria are met, proper fuel/air ratio/ignition source, the engine will start.

Of course, the above assumes that your engine has not been previously damaged (no compression), or improperly reassembled (liner reversed).

Try the above and get back to us here on the group. I know you can do it. Good luck.

mrfx2001

My Feedback: (2)

Well I see someone else has come to the same conclusion. I will be posting a thread later about the Chinese clones. They for the most part have the same problem. GMS, Thunder tiger and Tower hobbies are all from china and a knockoff of the OS product. I had 2 Tower, 1 GMS and 1 Thunder Tiger with the same problem. Good idle, lean on top end. All of these engines were bolted on the aircraft for break-in and resulted in disaster. The engine needs to be run in on a bench for ease of adjustment and max cooling to the point of piston cylinder fit. The story in short is that I acquired a pressurized fuel system from Iron Bay as to eliminate the system completely. What a nice piece of equipment. (This will be another post) I then benched up a Tower 46 that I have and runs like a cheetah. The benchmark was set. Engine runs, idles, and does not overheat on long runs. (30 min.) I bolted up the GMS and I could set the idle, the transition to full throttle was lean. If the top end was set the idle could not be obtained. While running the pressure system you have to pay attention to the pipe tap as the placement in the pipe can generate vacuum if in the wrong place. Pressure matched the Tower engine. The pipe was swapped for elimination sake. No improvement. The prop was the same used on the Tower engine. The Fuel was the same. The carb was swapped and the engine ran fine. Now to find the carb problem. I went to the garage and grabbed the flow bench that I built for model boat racing in the 80’s. My suspicion was confirmed. The top end was restricted at the idle adjustment point that the carb would provide reliable idle. All the problem engine carbs did the same thing. I wanted another bench mark so I went back to the garage and obtained an OS 4E carb modified for nitro boat racing. This carb will usually not run well on a stock piston and cylinder port timing. It ran well.
Now, what is wrong with the carb? I found a plastic part under the acorn nut where the needle went before the remote needle setup. The plastic was removed and the acorn nut was replaced and threads sealed with RTV. The barrel was compared to the working Tower 46 carb and I found that the idle mixture needle disengaged the spray bar sleeve at full throttle and the GMS did not. This cannot be compared to the OS as the spray bar is made differently. I put the GMS carb on the engine and adjusted for good idle, removed the carb and put a scratch on the idle needle at the end of the spray bar. I then removed the idle needle and filed the needle to the long side of the scratch. Then the needle was polished and installed. The engine ran fine. The flow equipment read in the range of the Tower carb. This engine was returned to the owner who has not installed it on an airplane to this date. The jury is still out. I will make a thread with pix if the flights are successful.
Fred

estradajae

Hi Guys!

Well, it seems the same problem that wass discussed on a GMS tread... take a look at the hole where the fuel nipple at the carb goes...in the GMS engine, the conduct was obstructed by a brass insert that was misplaced, so when the engine is at WOT, it just can deliver enough fuel to work properly, so the engine overheats, wuits and so on... you can test if this is what is happening by blowing through the nipple with a long fuel line...and take a look at the GMS problem tread...theese guys there solved the same problem!..good luck

Jorge

David Cutler

Is any part of the fuel tank directly touching a part of the fuselage, and/or is the prop balanced properly?

It sounds like your fuel may be frothing from vibration, which tends to make it seem like it's too lean, but not constantly.

Make sure the tank is as isolated as possible from vibration.

-David C.

estradajae

Check if the fuel nipple at the carb is blocked....The GMS .47 engines had the same problem, and it was widely discussed in a forum here... They found that below the fuel nipple at the carb, there was a misplaced brass insert, that didn't let fuel flow freely at high speed...the solution was to drill it out carefully, and all problems had gone..Hope it helps!

Jorge

mrfx2001

My Feedback: (2)

David,
An old trick that most all of the combat guys have learned about fule foaming is very simple. Most combat Rc aircraft are very simple and built for distruction. The fuel tank is mounted to minimize vibration but with the simple construction there is not much room for isolation. A additive to the fuel that I have found to be very helpfull for foaming is ARMORALL. Three drops to the gallon makes a lot of difference with no dretrement to performance. I found this hint some time back on this website and it has served me well.
Fred