I bought a Tower Hobbies .46abc did the complicated break in procedure exactly as printed in the instructions, I have run 2 gallons of PowerMaster 10% through engine. It will only tach 10700 to 10900 with a APC 10x6. I switched to 15% no improvement. I did the break in procedure again and no improvement, the engine has no compression and no power. I have checked all things, backplate, carb mount etc. I called Tower hobbies and they reffered me to Hobbico for warranty. I called them to request a new cyl and piston instead i get this customer service rep that implied since I switched nitro percentages I had to do the break in procedure again so the engine could get used to it, then wanted me to mail in engine at my expense to be checked out by them. What do you think?[][]

Breaking-in involves successful heating and cooling of the engine parts so they mate correctly from theoretical tolerance to "real" tolerance. Its a one-time event....changing fuels does not cause the metal on the engine to suddenly "reappear" to be rebroken in again. What changing fuels can cause is "old" cold carbon deposits to free loose and result in sudden "unreliable" performance...but this shouldn't happen on new engine where there is no deposits yet.

I think they are trying to get you to join their super saver club.

Definetly doesn't sound right and I'm getting ready to buy one of these. Any other symptoms? You tried basic things. You unscrew the needle value and look at it with a magnifying glass? Tried a different glow plug? (sometimes they are bad right out of the box...I had one that was brand new but one side of the weld was broken and barely making contact but enough to pseudo work)

10900 isn't exactly bad, what are you expecting from it?

I would be expecting 13,500...(but those are expectations) maybe its just still too new...too tight.

I personally never break my engines in with APC though. I break them in with cheap and light MA so I don't over work them and then go to APC later on...as a tweek

I replied to your post in another thread, but I will list it here also. I have two tower .46's myself and could not get them to run good. I later found out that these engines need a glow plug that has an idle bar. That made all the difference in the world.

I had three at one time. I only have 1 now. Anyway they all turned a 10-6 Rev-Up prop at 14,200 with Omega 10% on the 2nd tank of fuel. I thought they all ran like that? The one I still have has 100 flights on it and the compression is still like brand new. They guy that bought the other two thinks they are the greatest 46's ever made.

Enjoy,

Jim

buy a real motor like os 46. tower hobbies motors are not very good

lol.. Tell us what you really think...

If the Tower .46 no longer has compression, it was either bad to begin with, or has had an overheat.

We've tached a properly broken-in Tower .46 at about 13,300 RPM with an APC 10 x 6 prop.

Please remember that the Tower .46 engine is non-ringed, and can be ruined if it's run too rich.

I have 2 of the that run well. After the initial break in and a few flights they needed adjustments to the low & high settings due to poor transitioning but are fine now. Sorry to hear of your difficulties. Please keep us updated so we know what to expect from tower/ hobbico.

I to have been pleased with my OS engines. They seem to do as well as mySTs,Enyas, Saitos, K&Bs, Foxes,and one Magnum.

[hr]
Really?

Whys that?...never heard of that. How can the engine be ruined...I thought it would just 4-cycle and virtually all the break-in manuals I have (I admit to not yet owning a Tower but I have lots of OS) experience says run them rich and lean intermittently. Does it cause to much pressure on the head or something because you get unfired fuel as an uncompressible liguid instead of a compressible gas? Thats my guess..but I'd like to know if I'm right. And, if that is the case, not sure what rings would do to solve that issue.

To Bill Baxter, I need to add a little history I started flying RC in 1986 and flew daily until 1996 when I bought a real airplane. During that period I bought and broke in numerous glow engines even did q-500 racing. I did not run the engine too rich or overheat it per instructions. I did join the Tower Saver club to double the warranty to 4 yrs on the engine. During the first 9 out of 10 flights ended in deadstick. I had to adjust the low end extensively but finally wound up with a very satble idle and great transition but just no top end power. I called the warranty desk expecting them to ship me a cyl and piston as there advertising indicates with parts support. I did not want the bozo trying to tell me that if I switch nitro percentage it changes the engine configuration. He even tried to tell me if I ran reg unleaded in my vehicle and switched to super unlead it would take 5 to 6 tanks before my vehicle would adjust to the new octane and run correctly. I did check inside carb and inside muffler for restrictions and debris. I really expected this "power house" motor to turn a 10x6 around 14 to 15k. Am I expecting too much, but at 10,900 it does not fly a H9 ultra stick at all.

I also need to add. I bought this TH 46 because I have 3 friends and they each have a TH 75 2 out of 3 run great. 1 is new and just went thru the break in procedure and only has 3 flights on it. 2 dead sticks (low end still needs adjust)
On my 46 I have tried an OS #8 plug (3 of them) 4 tower hobby plugs, a used plug w/idle bar out of a very good running K&B 61
and nothing worked to make it better. It needs better compression.

I'm starting to think maybe a GMS instead of the Tower....[&o]

It is $5 cheaper...

ABC/ABN/AAC engines need to reach a certain temperature to get the proper piston/sleeve clearance. If run too rich, the sleeve doesn't expand enough and the piston is too tight in the bore. This will ruin the engine. A search for ACB+ Break In should turn up a few pages of posts on this.

2muchthrow,

I don't pretend to be an expert - here's my observations from my own experience.

There is a big difference in the break in procedures between ringed and ABC (or similar) engines. I recently researched this subject after buying a new OS46FX. I found out that ABC engines deliver the best performance and reliability if you:

- initially use a smaller propeller than normal eg. for a .46 use a 10x5 ~ 9x6. This ensures the engine can reach sufficient RPM but at a rich needle setting. A large prop will load the engine causing higher heat build up and requires leaner settings to achieve sufficient RPM.

- initially start it and get it to run at a slow 2 stroke ie. plenty of smoke but not 4 stroking and ensure you have the throttle at wide open. This ensures that the engine reaches operating temperature quickly and has plenty of fuel (and oil) doing the cooling and lubricating. Continuous 4 stroking will mean the engine is too cool and won't allow the cylinder and liner to expand to the correct dimensions.

- run the engine at wide open throttle at the above setting for as long as you can hold the head with your fingers - Don't burn yourself!! This ensures that the engine doesn't over heat. The engine does its !QUOT!break in!QUOT! whilst the piston and cylinder are reaching operating temperature. The engine wear that needs to take place is happening as it's warming up, not when running it too rich at a 4 stroke. 4 stroking will cause it to wear out.

- Stop the engine when you can no longer hold the head and let it cool down. I found that my OS46FX would take about 30secs to get hot - that's it just short bursts.

- Continue the process of short fast runs (with the smaller prop) for one or two tanks (about 10 to 20 oz). This will provide a series of heat cycles for the wearing process to do its job. The period of each short burst gets slightly longer as the motor is getting more !QUOT!run in!QUOT! - due to the tolerances opening up and partly 'cos your fingers get used to it!!

- Put on the !QUOT!normal!QUOT! prop and give it one more run to set both the low and high needles then go flying. Keep the mixture at a rich two stroke for as long as you like but try not to lean it out until a couple more tanks have been used.

The test is in the eating - I've compared my engine compression and performance with others of similar age and usage but they were run in !QUOT!by the book!QUOT! ie 4 stroking for a tank or two. Mine has better compression and performs beautifully.

There are some words of wisdom from Dar Zelon who has posted them in this forum - read them, he knows this stuff inside out.

i have a tower with great power...........here is what i did for break in..........first on 1/2 the tank i moved the needle from lean to rich every 5 seconds..........then on the second half or the tank i let it run at idle for 2 min then at full for 1 min.........repeat second tank......then i just flew it rich for the first few flights.............i also have a 91 FX and that runs sweet..........i broke it in poorly though i ran the low end WAY to rich and the high end alittle lean and that was on a 13-8.......also the engine on the first few runs was leaning out very badly the engine would be SOO hot.........but after a rough breakin i have a great engine with great compression and great power and has great relieabliltiy.........havent had a dead stick since (the fuel ran out once)

Well I don't have any problems with my engines...I just follow whatever the manufacturer tells me....that way is their problem if it doesn't work.


Sounds like what this guy did. If it is, than I say Tower cough-up or shut-up.

I have had a similar experience with my Tower .46.

I ran it in as required, but is would never allow me to lean the motor out sufficiently. Initially, I thought that it was due to the motor still being tight, but I have run about 10 litres of fuel through the engine (while flying), and still cannot get anything better that a rich 2-stroke run. Any leaner and the motor starts to sag. I have since put in an OS 46 FX in the plane and it was run in and performs perfectly. This lead me to believe that the Tower motor was just not up to the standard of the OS.

A fellow club modeller informed me that he had a Tower 46 and it was a real performer. He tinkered with the motor and even used the plug from his Tower motor. He was surprised at the poor performance of my motor.

Any help ???

Poteety,

We're not trying to "blame" anyone. If the engine's not doing well, we'd like to help you get it going well. We DO honor the warranty, just send the engine to us for examination/repair. If we have any difficulties we'll get back to you, otherwise, it's likely the engine will be handled under the warranty.

We can list dozens and dozens of reasons an engine will have problems similar to yours. If we can have the opportunity to work with you, you'll see that we are easy to deal with.

Please ship your item to:

Hobby Services
3002 N. Apollo Dr. Suite 1
Champaign IL 61822
USA

Package your item(s) carefully against shipping hazards. Please make sure it's insured against loss or damage in shipping. Include a letter with your name, return shipping address, daytime telephone #, Fax, Email (as much contact information as possible), and a detailed description of the problems you are having with your equipment. If your item is still within the warranty period, please enclose a photocopy of the purchase receipt to validate any warranty claims. As soon as it arrives, we'll take care of you as quickly as possible.

We hope you find this information helpful. Should you have any further questions or concerns, please do not hesitate to contact us at this email address. (Please be sure to copy all previous emails into any future questions.)

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Thank you all for the input, thank you Bill B for responding. I would have been more happy with you sending me a new cyl and piston, but I guess I have no choice but to box up this engine and ship it in at my expense, and then wait for it to be checked out.
Then it will be discovered the cleareance between the piston and the cyl will be out of tolerance.
If a new engine under warranty gets a new cyl and piston does the warranty dept test run the engine i.e. break it in?
Do you know the approx turn around time?
Thanks
Joe

I feel for you Joe.

Mike....it sounds like you had the Tower motor way over-propped....[X(]

Dave.

FWIW, I just ran one of the two new Tower .46 I bought for the Phoenix Sukhoi and Giles. On the test bench, after about 30mins of ON-OFF break-in, it managed just shy of 13,000rpm with an APC 10x6 on 10% nitro 20% oil. I stopped at a few clicks on the rich side, so it will probably go anther 2-300 rpm, if I pushed it. I don't think it's fully froken it yet, but I will break-in the rest of the way flying.

The engine was VERY tight brand new. I had to put the Tower HD starter on 24V to crank it over. So far it has been a good runner, powerful with a very low and steady idle - 2000rpm with a 11x5 APC. We'll see how it does in the air.