i have an evolution .40 in my alpha trainer,after-run oiled it in november, went to start it today and all she does is backfire, so hard that it stripped my spinner backplate. maybe i should just use an electric starter for the first few run ups, cuz it hand started fine last year.

Sounds like it loaded up on fuel. Did you pull the plug and use the electric starter to turn it over before hooking up the fuel line to it? Some engines will start with out doing this, but others really need to get the oil removed from the cylinder before firing it up. My OS .46 needs the plug pulled and the after run blown out before it will run good. My Supertiger GS-40 will fire up with out pulling the plug, but needs about 20 seconds to get the oil out of its system and start to run good.

Hogflyer

Hog, Nah im handstarting it, ill get the starter and batteries from work tomorrow i suppose

Might have too much oil in it too. Do yourself a favor and remove the plug, turn it over with the elec starter for a second or 2 and then put it back together and start it. If you do have too much fluid of ANY type on top of the piston you can bench the connecting rod. Isn't it worth the few seconds of time to make sure?

Most likely the oil, however if you are in Jersy, and out in the cold, along with trying to handstart, I suggest you are over-choking and creating a flooded condition.

Here's a trick that we used when I lived in the Chicago-land area and we were out ski-flying in the winter.

Take a small bottle, fill with half glow fuel and half GASOLINE. Prime with that mixture and start normally. Engine started down to 20* (my personal lower limit) just like on a nice 85* day. Gasoline's flash point ( the lowest temperature at which vapors above a volatile combustible substance ignite in air when exposed to flame ) is much lower than methanol.
That will also help clear that congealed after-run oil which clogs up everything. Even here in the humid South East TX area I never -now- use that stuff. Use a good fuel with at least some castor in the fuel, and a few squrits of light anti-rust oil every so often and your engines can be thrown in a box, then start right up after several years. Another myth of RC-- After-run oil!

Also might want to make sure you are spinning it counter clockwise. I had a brain fart one day trying to start mine clockwise and all it would do was sputter!!

I frequently start all my engines clockwise, then they backfire, and continue running!

didnt know i could mix gas and nitro, i have a new problem now, the sucker dont draw fuel, i might just yank my carb and soak it in fresh nitro for a while, my fuel is a lil old too i might get a new gallon

My Evo 46NT (on an LT-40 ARF) did this same thing and it seems like it was caused by flooding. A couple of time it started backwards.

Since its installed in a well proven plane I don't think the flooding was related to fuel tank position.

A simple work around is just don't prime it as much before starting (4 - 5 prop turns with your finger over the carb should do it).

Once flooded, you have to remove the glow plug and spin the engine up with your starter. Watch out for the fuel "shower".

None of my 3 GMS engines (32, 40 & 76) have this problem.

Other than this, the Evo 46NT has been an excellent engine. Very quiet (has an actual baffle in the muffler) and flies the LT-40 nicely.

Dave

it doesnt prime , its not getting fuel for some reason, i think its the old afterrun in the carb, ill soak it in fuel and blow out the jets

Check all your fuel lines to for pin holes. If you plane has been sitting for a while just replace them. Don't forget the line in the tank.

everything is new as of november, i had to clean the carb with nitro wash was all and replaced the lil tubing between the remote needle and the carb high side, it goes from medium tubing to almost 1/2 A tubing..........not gonna make a comment there but it primes now so we'll see what happens tomorrow. nice 67 there MR, ive got an 89.5 anniversary GT :-D

Just curious, how does a two stroke glow engine back fire.

I also have a 90 GT that has the 25th annaversary badge on the dash... I think that makes it a 89.5 as I understand the late 89's and early 90's were the only ones to get that badge. I'm not real familiar with Fox Chassis facts like I am with the first generation models.

m8 it is 1 of these things, crap fuel, rong plug,too much fuel in engine , overcharged glow starter

Overcharged glow starter? HUH???

if u load the engine with too much fuel, the engine will bounce backwards off the excess fuel when you are hand starting and run reverse basically, and a backfire is when the air/fuel charge lights off in the intake ( on a real car for instance) and it makes a loud pop, hurts your ears too. Ahhh the good ol days at the garage......

MR67, Ford didnt commemorate the 25th anniversary till 1990 but the true birthday was 89.5, came with 140MPH speedometer, the 90's had the horse badge on the dash, with the 140 speedo