Patriot

How long does it take to get one of these K&B 65 sportsters to run right? I got mine to start a few times but only runs for about a minute then quits. I noticed the exhaust is a grayish color, ,so I richened the heck out of it, and still grayish color, only with lots more goo.
Is this normal for first runs on this engine? It has the finned carb and seems to work well, but just doesn't seem to want to stay running for a long time, nor does it want to wing up to full throttle before it quits. If I run it lean then it really hates me, so I am not even going to try that. The needle is about 7 turns open, and really gushing oil out the exhaust, but it seems to like that better.
I am running 5% nitro Powermaster w/18% castor/syn blend, I think it is 6% castor, and 12% synthetic.
I have also tried two differant plugs. The original K%B and an OS-8.
Also, I am running a 13x6 Zinger.

Any suggestions? Or, just keep running it like a slob, puking its guts out until it settles down?

My arm is getting worn out. I need an electric starter for this one.

Patriot

RaceCity

Patriot...

Is this on a test stand, or the model???

Try to get the motor on a test stand...makes it a lot easier to babysit the set up.

7 turns out on the HS needle is an awful lot. Sounds like the motor is having a tough time getting fuel.

Check your fuel tank/lines for starters. Tank on level with the carb, no pinches/pinholes in the fuel lines.

Ensure the backplate and carb are properly seated and tight.

Ensure the muffler is mounted securely.

Try to use a slightly smaller than normal prop (ie: 12-6) for break in, and a 13-6 for the flying afterwards.

It wasn't uncommon for these motors to have some metal "swarf" in them which needed to be flushed out before
running the motor. Sounds like we showed up a little late for the dance so to speak on that issue....

The fuel you're using is good, but some added oil (castor) would be better for these motors. Try to get the oil content to
at least 20% if you can. (about 5 oz added to a gallon of fuel is about right)

The supplied plug (KB1L) and the OS8 are both well suited to this motor, so you're OK there.

That's where I'd start with this anyway.

Hope it helps,

'Race

Flyboy Dave

My Feedback: (21)

You might try pulling the needle out of the carb, and blowing the lines
and nozzle clean. There may have been a bit of debris in the tank or
lines than you didn't see, and it is causing grief !

7 turns out on the main needle....[X(]

FBD.

Patriot

I know 7 turns is way too much, so I cranked it in to 3 turns to today and she ran for a couple minutes. Not great, but better. So, I turned it in to 2 turns and she runs a little better still. I think I was drawing so much fuel I was cooling the glow plug too much, as it would quit as shortly after I removed the Ni-starter.
I got it to run much better at 2-2.5 turns, but will work on it some more. I don't have an electrical starter, ,so I only toy with it once per day, as my arm is getting aweful tired, and I am actually in pretty good shape. LOL

Anyway, each time I run it, the engine goes for a little longer without quitting. I think I need to just keep running this thing. The exhaust is still coming out gray in color. Almost like there is alot of wearing in going on. The engine is not getting too hot, as I can touch the head after it runs and it is ok. Hot, but not rip roaring.

I think part of my problem is the fact that it is mounted inverted on the plane as well. I don't have a mount for my test stand for this one, so I was just running it alot on the plane. I figure it will get there eventually.

I did remove the needle and blow it out, everything is nice and clear.

I have noticed these engines make alot of mechanical chatter because it uses a bushing design, not bearings like the newer ones. But, I heard that is normal for this engine, and as long as I use castor in the fuel, it should be ok.

Progress is being made, but ever so slowly.

Patriot

DarZeelon

Curt, Aaron,


Aren't the Sportster .65, .45, .28, .20 series engines, of bushed ABC construction?

If so, isn't 25% Castor and a slightly rich mixture the correct break-in method?
Heavy piston crown scuffing can account for the pulverized aluminium...

This happens when ABC type engines are broken-in cold and rich; not hot.

Hobbsy

My Feedback: (102)

Many times when the needles are turned way out, the fuel flows back into the tank between flips. Also as Dar mentioned it needs to be broken in fairly warm and fast.

Bruce Rolfe

My Feedback: (37)

I found on my 45 Sportster that I needed to remove the Head Shim. After I did that the motor really came alive. Not a deadstick landing after either. Just a thought.
Bruce

Sport_Pilot

The Sportsters are a reversed AAC construction. The piston is plated and the sleeve is high silicon aluminum. They tend to have more flouling of the plugs from worn aluminum than normal AAC construction. Best to use a cheap plug during initial break in. If it won't tune, replace the plug.

JCM

My Feedback: (2)

I have two of these, I run 15% nitro, 20% castor.
I just checked where I have the main set and it is
4 1/4 turns open.
All I do is start an engine out rich and with it
wide open screw the main in for max rpm then
back it out a little.
I am using the K&b standard glow plug and it
seems fine.
I will say that these engines seem to start hard,
and when hot real hard to get going again. Let it
cool a few minutes and it starts easier.
My two only took two or four 8oz. tanks of
fuel(15%) to break in each. One tended to quit
suddenly the first tank or so but the other one
was good to begin with.
Also, I used a 11x7 prop.
Some people think these engines are a
little on the low power side but I think
that they may be quite powerful when well
adjusted.
Good luck,
Jim

Patriot

UPDATE:

You guys won't believe this. I found where this thing will actually stay running....

1 1/2 turns out!!! Holy Smoke-A-Roonies!!!

Can you believe this? I thought for sure it would fry itself, but none-the-less, it runs like a top. I got it up to full throttle today (finally), and stayed running without flooding itself (one full tank). At full throttle it is still sputtering rich just a tiny bit, which is ok, as it needs to run in a bit more. However, I did notice the oil discharge is very plentiful as the wing was drenched, and it is slowly getting a little less gray as it runs. I do think the aluminum in the exhaust oil is normal as I do believe these are ABC engines.

It seems to get up to full throttle pretty quick on the stick, only a 1/2 up and she's at full blast. So, I think I will program the radio to give a little smoother transition.

I know this sounds very lean, but something must be up with this needle. Remember guys, this engine is mounted inverted, so fuel delivery is not a problem. the stuff drips out of the carb on its own. I didn't have an extra mount for my test stand, so I am just running it in on the plane.

Some of your advice gave me some ideas and really helped out.

Don't hesitate if you think there is anything else I need to know about this engine, as I don't want to ruin the poor thing.

Patriot

MikeSell

My Feedback: (2)

Upright or inverted the fuel should not run out of the carb. The fuel tank should be almost centered at the spraybar height or you will have problems in the air. Consider how rich it is now then invert the plane in flight and too lean deadstick.
These are AAC engines not ABC. They have no removable liner. That is the very reason they cool so much better. If the bore is damaged you replace the entire cylinder.

Hobbsy

My Feedback: (102)

You simply cannot go by the number of turns, even from engine to engine of the same make and size.

Ed Smith

Believe me, aluminum in the exhaust oil is neither normal or desirable. If aluminum is coming out of the exhaust then metal is being removed while the engine is running. When you purchased that engine all of the machining operations had taken place, there were no more metal removal operations needed. There is a good chance that the piston/liner fit has been destroyed by running the engine too rich and too cool.

Dar Zeelon posted the complete, correct break in procedure for ABC type engines on this Forum. Do a search and take a look at it.

Ed S

Sport_Pilot

It is normal during break in.

Yes, the aluminum is being worn off the piston as is normal during break in and to a much lesser extent throughtout its life.

If this was possible then there would be no need to break in our engines. Engines with short break ins are built with closer tolerances, have softer metal, or both.

Patriot

All I know guys, is that this little guy surpised me with is 1 1/2 turn needle setting. The center of the fuel tank is inline with the carb, so when the tank is full, the fuel level is a little higher than the carb, and drips just a tiny bit when the carb is fully opened. About one drop every 5 seconds or so, not like constant fuel pooring out.
The plane is an ARF, and only one way to install the fuel tank, and only one way to mount the engine as everything was pre-installed (engine mount, and fuel tank mount with a hole in the firewall for the front of the tank). If it does become a problem during flight or testing, I can just go ahead and install a Cline fuel regulator. They always fix this kind of problem. So far, it seems to be set up pretty much the way I would set it up myself, if I had built it from scratch or a kit.

As for the gray exhaust. As I said, it was still there yesturday, but began to get a little less as I ran a whole tank through it. I am assuming it will subside over time. I bought this engine new, but is old stock, so it has been sitting for a long time. I don't think they make these anymore like this one. This is the one with the finned carb and needle in the carb, which came out before the remote needle valve version. So, I think it must have been made in the mid-90's sometime.

Today, I will run a full tank through it again, and see how it's doing.

Patriot

Ed Smith

Believe me, aluminum in the exhaust oil is neither normal or desirable.

If aluminum is coming out of the exhaust then metal is being removed while the engine is running.


When you purchased that engine all of the machining operations had taken place, there were no more metal removal operations needed.


Where do they get this stuff??.

I do have knowledge on this subject. If anybody firmly argues that aluminum coming out of the exhaust is normal then they are way beyond any help or advice that I have to offer. I will no longer waste my time with this.


Ed S

DarZeelon

Ed,


I agree with you for the most part.

The break-in thread that I began is [link=http://www.rcuniverse.com/forum/Tapered%2DBore_Engine_Break%2Din_%2D_Upgraded/m_1850473/tm.htm]here[/link].

The whole purpose of the warm, operating temperature break-in is to prevent excessive scuffing of the piston's crown, by having the sleeve top expand due to heating.

Very little aluminium should wear of the piston, if any at all.


However, I am told the Sportster series engine, which I never held in my hand yet, does not have a tapered-bore, like other AAC type engines. It should use a warm break-in, since it causes parts to mate more quickly.

I would worried by the described amounts of aluminium that Aaron noticed.

That is not normal!

Patriot

Sorry fellas, didn't mean to start a p***ing match, but I will say this, after running it for only one tank, the amount of aluminum in the exhaust oil is deminishing, and noticably at that, after only one tank. So, I am sure there had to be some wear going on there, and it is going away. Keep in mind, this engine sat for a long time, as it is new, but old stock , so I am sure, now that I think about it, there was probably a bit of gunk in there that worked itself out. I suppose I should have flushed the whole thing thoroughly before running it, but it is a bit late for that now.
It actually is starting to run much better.

Generally, I would agree, that aluminum in the exhaust is bad. My Enya four stroke did not have anything, but its alloy is very hard by comparison to K&B. Plus this is an engine that was old, so I honestly am not too worried after seeing a noticable drop in the level of aluminum in the exhaust after such a short run.

I will let you all know what I see on my next run.

Patriot

Patriot

Ok, i just got done running a second tank through it, and the xhaust oil is still gray, but the engine does not seem overheated. As a matter of fact, the second tank actually ran more smoothly than the first, ad the engine is getting more responsive.

One thing I did notice, is when it was at full throttle, it wounds up nicely, but after running a bit, the rpms drop off a bit, then kind of settles out with a bit of sputter. I think it is still a click or two rich, as evidenced by the goo all over the plane.

I am going to seal the muffler and run an exhaust extension, as the plane is getting excessively full of oil. I will do this before the next run.
Patriot