Hey guys I need some help. This is my first glow plane and I am having some problems. I have a thunder tiger .25. ok It started and ran in my yard yesterday after a long time of trying, then it wouldnt start after that. This morning I went to the field with my dad to maiden the plane and it wouldnt start again. The engine is not new but it has great compression. The glow plug is the one that came with it and seems to be pretty old but still glows. I think I will try and get another one. also its not the glow starter becuase I charged both of mine and it wouldnt start with either. btw all I have is a chicken stick. any advise? Thanks in advance for the help.

Go ahead and get a couple spare glow plugs.
An electric starter is very nice ESPECIALLY WHEN DIALING IN A MOTOR. After you have a motor dialed in the chicken stick is fine.
Try this starting technique. always run the fuel out after the last flight of the day. if you suspect the engine is wet. remove or clamp off the fuel in line remove glow plug and spin it a few times upside down and in a position to drain the cylinder and exhaust. Check the glow plug for a BRIGHT glow while its out.

reconect line and install plug. hand turn the prop WITHOUT glow drive until fuel is in the line to the carb. move throttle to just a few clicks open. Flip the prop vigorously 2 or three times without the glow driver. apply glow driver and flip to start.

sometimes in old engine removing the needle and blowing some fuel out clears gunk.
A new O ring on the needle can save HOURS of agrivation don't ask me how I know.

Ok thanks for your help. I would have gotten an electric starter but they are like $60 so I didnt but I guess Ill get one. I am recharging my glow starter and if it starts in my yard again I will be pretty angry...really wanted to maiden it today and wouldnt turn over at all...[] lol. maybe I can get my dad to take me back to the field if it will start. Ill let ya guys know.

When I used to work as an auto mechanic my boss used to say that to make an engine run you only need three things - spark, air, and gas and that everything else was just tuning. Since this is a glow engine we can change spark to "a reason to fire" and gas becomes glow fuel. The air takes care of itself.

Before you look at the engine, check out your fuel. Is it new, or did it come with the old engine? If so, it's suspect. Methanol (the main part of glow fuel) will keep virtually forever if it's sealed up well but it is hygroscopic, meaning it'll absorb water from the atmosphere if not sealed up properly. There's no real way to tell if it's absorbed water (if there's a fair bit it might get cloudy) and it's almost impossible to remove the water (no, you can't freeze it out - the water molecules are bonded to the alcohol molecules) so if your fuel's old and suspect throw it out and buy some new fuel. You also need to have the right amount of oil in the fuel - I'm not familiar with Thunder Tiger's but typically 15% oil should be fine. You'll probably also want some Nitro (nitromethane) in it... typically 5-15% is heaps for two stroke engines.

The first thing to do on the engine is to get a new glow plug. FYI a glow plug works because of a reaction between three things; heat (initially from the battery, later residual heat from running), pressure, and a catalytic reaction between the methanol in the fuel and the platinum coating the plug's coil. The platinum will wear thin sooner or later which is why plugs stop working, even though it'll still glow with the battery connected.

The second thing to work on is the carburettor. Check to see that the carb is firmly mounted against the crankcase and that the O ring sealing it there isn't cracked/missing/etc. A loose carb or damaged O ring will allow air to get in which will make the fuel mixture very lean (too much air, not enough fuel). Check that the barrel rotates freely and doesn't feel "gummed up" with old fuel/oil. You need to check that there's no fuel blockage too - do this by connecting a length of fuel line to the inlet nipple, opening the barrel wide, and blowing into the line. You should be able to hear air hissing through the carb - if not try open the high speed needle a few turns and try again. If there's still nothing, pull the carb apart and find out why. If old fuel has evaporated in the carb it can leave the oil (often castor oil) in there to turn into gum which will stop the fuel getting where it needs to be - you can wash this off by soaking it in new fuel and carefully wiping with a coitton bud/cloth etc.

The next thing to check is the mixture settings. Your carb will have two settings - the high speed needle which will be fairly obvious, and a low speed needle which will probably be a screw hidden in the throttle shaft. Rather than typing out the whole procedure for setting the mixture here, just [link=http://www.lymanslack.com/Articles&Archives/st.htm]click on this link[/link] to go to a good article about it. It addresses Super Tigre engines but the principle is the same.

Finally, go over the engine and make sure all screws etc that are supposed to be tight are tight. Once you're sure you have fuel, air, and an ignition source all the right places and proportions, fuel up the tank, open the throttle wide, cover the air intake of the carb with your finger and turn the prop through a few (2-3) full turns to "prime" the carb (this sucks fuel out of the tank). Then close the throttle, connect the glow starter, and start the engine.

Oh, and I'd really suggest investing in an electric starter - it makes life much simpler. Good luck, and let us know how it turns out.

Thanks for your help sandmann, the fuel is good. I was going to buy a new kit but i guess getting the engine to run reliably is more important so ill get an electric starter(which is the same price as the kit i want (mojo 25)[]) lol. Im going to try and start it in a few minutes.

Good choice. If you want to save a few bucks at first you can run it off a car/motorbike battery if you have one around the place (just be careful of the acid) but you can get 12V 7Ah gel cells for about $20 and a charger for a few bucks more. Until you get into engines bigger than 120's (in fact I even use mine on a twin cylinder 160!) that starter'll make starting every engine you have so much easier - you'll wonder how you lived without it.

You should not have to buy a $60 starter to start your small engine with. A cheap one on a 12v battery will do fine. Something like this:

http://www3.towerhobbies.com/cgi-bin...&I=LXJC35&P=ML

Wow i didnt see that one! lol when I looked on tower all I could find was the $60 sullivan ones...thanks! also now it starts! I cant wait to go fly it later today! thanks for all the help guys

I have a TT .28. I learned a number of things on this site. One was that my TT has an air-bleed carb, rather than a two needle carb. Adjusting the idle/slow-speed air bleed screw is back-wards of a two needle. So, if someone tries to help you, and doesn't understand air-bleeders.... he/she is probably turning the idle screw in the wrong direction.

The other was that the little engine wouldn't suck fuel with hand turning at all. With an electric starter ( my electric starter is VERY similar to the $19.00 dollar one already suggested above) the fuel was easily drawn up into the line. She then started easily most of the time. regards, Rich

p.s. When you get the electric starter, you may find that you have to reverse the rubber "cone" so that it will fit the smalli spinner or nut of the little .25 engine. RG

Yeah, a good way to get it to fit really good is to spin the starter and hold a pocket knife blade against the inside of the rubber cone as it is spinning to shape the rubber so it will grip your spinner really good. I had to do this to get my starter to grab a spinner nut, and it worked really well. It does throw little rubber shavings all over the place, so do it outside.

If you suspect the engine is flooded you can easily clear it with an electric starter by removing the glow plug and spinning the engine a few seconds. Watch out for the fuel spray coming out the plug hole.

Wow now that Ive actually got it tuned I dont even think I need the electri starter. it starts right up! Thanks for the help guys. I am going to maiden my scratchbuilt flycat tomorrow and if it dosent fly I am getting either a taylorcraft or the house of balsa at-6/p-51 as a kit to build up. cant wait(even if it flies im getting one of those kits but im getting a new radio first then (dx5e))