I have the O.S 65 engine and the problem I'm having is try to get it started. When I hand prime it I can see the gas coming up to the carburetor. That’s turning the propeller and plugging the hole in the back of the muffler. However, when I put my starter to crank it the gas starts to backup back to the gas tank. What possible cause this problem.

Thanks,

Usually when the engine fires it draws the fuel up to the carb so it shouldnt be a big deal. Do you have the main needle adjusted? about 2 turns out should get you started.

ok this is a new one on me.....what happens if you continue to turn the engine with the starter? usually when i prime i do it this way....glow stick off the glow plug, open the throttle full, put your finger over the carb opening and turn the engine to the left as you're looking at it.....stop when fuel gets to the carb...then close the throttle except for the trim for idle....hook up the glow stick and start the engine with the starter

Iwill sometimes hold my finger over the muffler outlet briefly while cranking with the starter on a hard starting engine. You should be able to start it a like 1/4 throttle or less.

I'll try it on tomorrow and see what happens, and thanks for responding.

When you see the fuel reaching the carb DON'T STOP

Continue turning the prop x2 more revolutions.
Then remove your finger over the carb (..used it to prime it )
Turn the prop x2 more revolution to be sure your engine won't hydrolock..

Then install the glowplug driver and use your starter.
Throttle must be set at 1/4 of the movement,
or 5mm open!

Been there...done that...my O.S. 65LA never let me down !

Kostas,
Speaking of the OS engine, I'm about to build a giant big stik. I have my eye on the O.S. 160FX Ringed w/Muffler. Is this a good engine for this plane? Also, the problem I was have with my other plane was I had a pin hold in the tank cause it to loose pressure. All fix up now and thanks to all for the help.

Sure, the OS line has a great reputation. The only one I ever had give me any trouble was a 91FX. And I have had a bunch of O.S. engines over the years.
Stiks are GREAT as long as that motor is in the recdomended range or a bit bigger it should do the job nicely.

On your 65 LA be sure the air bleed needle is dead in the middle of the hole. Find a pin or paper clip that is half the size of the air bleed hole and use it as a feeler gauge[8D]
the needle itself has a blunt taper and is hard to visualize in the hole sometimes. You want the tip at half way not the begining of the threads. Set it a bit rich as these things have lined cylinders that DON'T LIKE BEING LEAN.

The LA 65 will start easier with a long prop.<div>
</div><div> Check fuel lines and tank .  Any small leak can cause this problem.</div>

$30 more and you can put in a DLE 30cc.....You wont be sorry!

Scotter,
I never consider a gas engine but how much more maintenance would be involved? Also, what addition of equipment other the the glow I need to purchase.

Just need the engine. Turn on the ignition, hand start and fly. You don't even have to dran the tank at the end of the day. $3 gas vs $20 glow, that's easy math.

Gas engines tend to produce more vibration
and being more heavy in comparison with a glow-engine of similar power...

mrcoolpop ,

your Giant Big Stick will fly with authority using the O.S. 160FX.
I had an O.S. 160FX. on my Giant SuperSportster
which i think is heavier that your Stick,sooooo.......

But plz explain to me this : ' Also, the problem I was have with my other plane was I had a pin hold in the tank cause it to loose pressure. '

I took out the tank to make sure that the lines were correctly installed. That’s when I notice a dripping from the coner of the tank. I had some epoxy patched it up and let dried. I installed it and the gas flowed through the tube. It then started and running fine now.

If it was me i'd replace that tank,
for safety...

You don't know if epoxy holds up as time passes by..
And you don't want balsa filled with fuel []

I never consider that but will put one on order. And back to the engine, I think I'm going to stay with the 160 FX.

Get a new tank pronto......I doubt the epoxy will hold for long

Yes,indeed,

the 160FX is a very nice choice.

If you wanted less oil mess,
i'd suggest you a SAITO FA-150S.....wonderful engine!


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Very Nice, but out my price range.

Kostas...beautiful country in the picture...is that your field in Greece?

Yes it's my/ours field in Athens/Greece.

It's the place where my local aeromodelling club is located. [8D]

Very nice...reminds me of Hawaii