...Don't know....

[Bootlegger]

      if this should be in the engine section or not, but I have been having trouble getting my new os 46 la engines to start for the first couple of times, it seems that they don't have enough compression.
     They will stop on compression instead of flipping thru, so today I tried something new, I oiled the engines, installed a glow plug, then mounted them in an drill motor and ran them for a couple of minutes.
   They did get rather HOT so maybe this will help getting them started.
  Anybody else having this problem, and what did you do to get them started???

[Dick Pacini]

I have a new LA 46 still in the box that has not been run.  However, the manual that came with it is pretty thorough and lists the starting procedures and a troubleshooting chart.

My first question would be what you are using for fuel, percentage of oil and what kind of oil.  That could affect the compression.

If you have clean fuel and a good glow plug and starting battery, it should start as long as it isn't flooded but has been primed.  This stuff is basic and I apologize if I have offended you.  I am just getting back in this hobby after 35 years, so I am having to re-learn it all myself.  Glow engines have evolved to a point, but they still function the same way.

I would not spin the engine with a drill motor.  The cylinder needs to heat up from combustion, not mechanical friction.  If no fuel or lubricant was fed at that time, serious damage may have occurred.

[Alan Hahn]

Gil,
I tend to agree with Dick.

The LA series of engines are usually pretty user-friendly engines. I haven't ever had an issue getting them to start, even when new.

I can't tell from what part of the country you are in, but I assume it must be somewhere where the sun is shining--but it still may be relatively cold. These type of engines typically are pretty tight when cold, due to the fact that the brass cylinder liner expands/contracts more than the aluminum piston. So to get a good fit when at running temperatures, they must be tight when cold. Now if you throw in winter temps (even in sunny climes!), they may be very tight when new.

If you run them in the way you did--on the bench and cold, you are liable to completely destroy the compression when the engine gets to normally operating temps.

So don't do that!! I hope it isn't too late as is.

[Alan Hahn]

Also go to the engine section and click on one of Randy Smith's stickies. I believe he has a whole list or breakin instructions.

[Jim Oliver]

Gil,
On NEW abc/abn type engines I have sometimes used a heat gun to warm the top of the cylinder and head a bit before the first start.  This causes the liner to expand away from the piston a bit to make the first few flips easier than when cold.

It is very important to not turn the engine over when it is new and cold---serious wear usually results.  At this point, I would suggest that you flush out the cylinder to be certain that no very tiny metal particles are present, then attempt to start the engine.  Maybe it will be OK; if not, new piston/liner sets area vailable from Tower.

If you must remove the liner from the case, try very hard to reinstall the liner exactly as it was to match up the liner/piston wear areas.

Not mentioned very often, there is a "GOTCHA" with break in of ABC/ABN engines.  To avoid damage to the rod, it is necessary to have enough fuel flowing through the case for good lube and heat removal.  To avoid damage to the piston/liner, it is necessary to get the top end up to operating temp very quickly. This is usually done by running a fairly light prop load (to help protect the bottom end) at a slightly rich two stroke mixture setting to help get the top end up to temp quickly.  I usually use the same fuel that I plan to fly on........with a prop one inch shorter and or one inch less pitch than normal.

The OS La engines and the Brodak 25 and Brodak 40 can be difficult to start the first few times because thay are fitted so tight.  Using the heat gun will help, as will being very careful to not get them flooded.

Probably more than you wanted to know........

Cheers,
Jim

[Bootlegger]

  Guy's thanks for the response's..  I am using Power master fuel 10/22 with added castor for more cooling and lubricant.
   If I made a mess, I got a chance to learn, I don't intend to make this mistake again. 
  Again thanks for your advice, and Dick I didn't take your thought's as an insult, I appreciate your thoughts as I do everyone's...

[Brian Massey]

When I bought my first LA46 I was troubled with it's refusal to start on the bench. I slowly figured it out, it seemed to me to flooding very very easily. It took some doing on my part (I'm a fresh retread just getting back into it too.) but finally got my 20 or so bench runs in.

The first time on a plane and at the field I primed, flipped and was stunned! It started right up and has been that way every since. I'm using 10/22 50% blend also. I'm been flying the engine for about 5-6 months and have to say that for a box stock engine, it is great! 

Brian

[scott bolton]

  Gil, Hope to help you a little bit. I have several la46's and they are great engines. But they do have a unique starting procedure so here goes. If the engine is inverted I flip it over put my finger over the venturi and pull it through ONLY TWICE. Then flip the plane back over add the ignitor and should start with in several hard flips. These engines can flood easy compared to the old loop scavenged motors ie.fox 35,s etc. The fuel your using is OK, Also if you want to refuel right after a flight I usually only pull fuel through the motor one time then restart and fly again. Hope this helps, please let us know the outcome. PS.these engines break in very easy as well just 6 or 8 tanks through it with a 11-4 prop or so and go have fun!!! THANKS Scott.

[Paul Taylor]

I like the LA's and will take them over any other engine for a 20-40 size plane.

Chris Sterner showed me how to get one flip starts with these puppys.

Put your finger over the vent and pull thru 3 times. Remove finger and flip hard 3 times, without the glow starter.
NOW attach the glow starter and flip one time hard. It should fire right up if you have the needle set correct.

Tach it between 9800 and 10200 rpm depending on prop and how fast you want to fly and let her go.

I do this with a box stock engine.

[Steve Helmick]

Try priming the engines with Ronson lighter fluid (or naptha). Be sure the battery is well charged, and the glowplug is a hot one. I wouldn't expect any problem with starting, unless you're using the RNV. The problem there is "drainback" which doesn't seem to be a problem with a front NV. Most guys put the LA's in their plane, run one to three tanks through on the ground, and fly them. I have run a .25 and a .46, and each got one ground run. They "followed the needle", ran steadily, and showed no signs of having any problem, so I flew them the next run.
In both cases, they ran well, and I had no regrets. Both still run very well.

The .25 did not get converted to FNV right off, but shortly did get the .25FP backplate and a K&B NV Assy. after showing some bad traits.  The .46 got the .40FP backplate and a ST clone NV Assy. right from the git-go. It's easier that way...  Steve

[Perry Rose]

I have 2 LA .46's that act the same as Gil's. I ran each for 20 minutes on the bench.. I had the chance to fly one today and it went better than expected. I heated it with the heat gun at home and put it in the cab and left it there for about 25 minutes. I took it out just before hooking up the wires and, with the plane on it's wheels, choked it 3 times. The fuel ran out when I took my finger off and I flipped it 4 or 5 more times. Then hooked the battery to it, still on it's wheels, and flipped it about 6 times when it started. The temp. was 40 degrees and I didn't use any lighter fluid or other prime. Same thing on the second flight.

[Bootlegger]

        Guy's, ran one of the engines today, started on the second or third flip, got about 35 minuets run on it and it ran just great, will get the others run this week.
   Thanks for all the responses and advice...