Hi ive got an OS.46 2Stroke and my buddy has an ASP.52 4Stroke he brought it over to the house the other day and wanted to test run it. I got it fueled up and ready to start we worked seems like 30 minutes to try to get it to run I had the wire from my starter hooked up to the battery as follows. I had the negative wire to the negative terminal on the battery and possitive wire to the possitive terminal. I thought to myself maybe i have the wire hooked to the battery wrong I switched the wires it started the first hit of the starter. Okay when we went out to fly saturday i hooked the starer up just like we started his with that day negative wire to possitive terminal and possitve wire to negative terminal we got my OS.46 ready to start it started on the first hit i flew for a while and landed well we got his ready we worked for 30 minutes to get it to run it would start but die befor you could make it to half throttle we adjusted the low side and high side with no luck I switched the wires on the battery possitive to possitive neg to neg and it started first hit of the starter. I thought all engines started the same and run the same direction?
so whats the deal what direction is the starter supposed to be turning to start the engine clockwise or counter clockwise?????

Unless you have a reverse rotation engine, They generally start counter clockwise.

rbeck

Four strokes often fire better off the back side of the compression stroke.

The engine belong's to you guys. Do whatever you can to get it to work. With experience, You will be very firm in your thought and be back on here helping someone else?

Good luck,

Jim

Is there any way to tell if it is a reverse rotation engine?? One more thing after we got it to start and run we tuned it used a tach to do this we got it up to max rpm then backed it down checked all the controls to make sure they went in the right direction and no mater what the plane would not leave the ground. It had enough elevator in it that if it did leave the ground it loop 3 feet of the ground seems like it just wouldn't pick up enough speed to lift he started out with a 10x6 and went to a 11x7 with still the same out come I just don't get it any ideas??

Won't take off:

Wrong prop (try a different prop, in the recommended range for the engine)
Engine running poorly (Tune or repair engine to obtain peak performance)
Engine too small (Get larger engine or smaller plane)
Plane too heavy (Put plane on a diet, or fit a larger wing)
Wheels too tight. (Loosen wheels)
Wheels too small (Get larger wheels)
Grass too high. (Cut the grass, or find some pavement)
Mud/water too deep (wait until field dries, or find some pavement)
Negative AOA while on ground (adjust landing gear to gain level attitude, or slight positive AOA)
Wing not covered (cover wing and try it again)
Hold-downs attached (free the airplane from its restraints, and try it again)


If none of the above work, suggest that your friend get a boat or car/truck/buggy instead

The plane is a Sturdybirdy so i figure a .52 4 Stroke should fly it shouldnt it??

I never cared for those things much, but yes, the 52 should fly it.
(On an 11x6, 11x7, or 12x5 prop, probably.)

Have him go over some of the other things... I was being facetious with a couple,
but most are things which could be keeping him on the ground.

Has the plane ever flown before? With what engine, and how did it fly then?

Special attention to the way the plane sits on its gear, and how tight the wheels are.
If flying off grass, the wheels may seriously be too small, too.
(Too much drag on the wheels, so it never gets to flying speed)

I have an Advance 40 that will barely pull itself into the air, with its current wheels, if
I try it from the grass. It flys just fine from our paved runway, though.

We do fly off grass but i didnt have any trouble with mine it left the ground within 15 feet. this was the first flight on the birdy and engine not sure on the size of his tires but they r bigger than mine i think they r like 2 3/4 inch he has plenty of AOA the last prop he tried was a 11x7. Do you think it could be a reverse rotation engine? I started my OS counter clockwise the .52 would start but wouldnt run past half throttle I switched the wires on my starter it started and run so i dont know what the deal is.

The engine could be starting backwards and that's why it will run very poorly with no power. When it runs backwards it will spit fuel out of the carb and you can feel the air off the prop towards the front. Check that first..

You'll know when it fires properly.. it will rev up alot better running the proper way. That ASP is not a reverse rotation if I remember correctly..


by the way.. cool nickname..

by the way the .52 is plenty .. I trained a guy awhile back who had a sturdy birdy with a old o.s 40fp and it was enough..
I thought the plane was a mess though.

RE: Engine running backwards or not:

If it's pulling the plane forwards when you rev it, that's a sure sign it's not running backwards

As for which direction the starter is turning, both your engines should be cranked
counterclockwise. (From your perspective, that is) However... it is entirely possible that
his is cranking better on the backflip, even with an electric starter. Especially if it's
a weak starter, or if he's "bumping" the starter, instead of leaving it in place until
the engine is actually running.

Just thought of something, due to the nature of these questions, and the planes involved...
If he's never run a four stroker before (we're talking... hours and hours experience needed),
he really needs to get an optical tach to check for peak rpms, and richen up a few hundred
from there to attempt flight. They are very hard to tune by ear, for the inexperienced.
He could simply be running too rich to develop enough power for a takeoff. Just a thought.


I also noticed that you say this is the maiden flight of this particular birdy.

I'm not familiar with how complete these are when you get them... but it could be that
he has an incidence problem keeping him grounded, too. Just something else to check.

I said I didn't care much for them... but I've never seen one "not fly". They fly fine

CäÞ¯²³² ,

You mentioned you tuned it using a tach, but didn't mention the results (RPM). That kind of information could answer alot of questions. As a new engine, it may not be fully broken in yet, and isn't achieving sufficient RPMs to fly.

I guess I missed the part about him already using a tach, earlier.

I know this may be common sense to most, and I won't go into the sordid details of my own experience,,, but,

Is the prop on the right way? and

It isn't a "pusher" on the wrong way, is it??

John
aka "Murphy"

Putting a prop on backwards only reduces the thrust, it'll still work.

Hi, well we might have figured it out I didn't think about it but could the engine be out of time??? The reason I ask is this when he first got the engine first thing he done was tried to tighten the glow plug up like superman and striped out the threads. He had to order a new top assembly so he striped the motor down could he have put it back together wrong??? He e-mailed the place about the engine and they told him that thats what it sounded like to them that it was out of time they told him they would fix it for $35.00 but he thinks that is too much money.