I've used them in 2-56 size and even smaller in metric at work. As I said before be real careful and real straight. A little loc-tite can be used to hold in the helicoil if needed but NOT on the screws.

http://www.mcmaster.com/
2-56 p/n 91732A892
2.5 mm p/n 91732A873

buy complete kits or individual inserts 91732A873 (need to have installer and tap though and please note the tap is a special heli-coil tap.)

Like bruce say, the 2/56 are slightly larger than the metrics....jack screws for D-sub are 2/56.
This way you can still mount the bracket onto the jackscrews. (male to female)

or get a slightly longer metric..then use washers behind the bracket..
maybe there's still some threads left on the inside.
Just go to your LHS and get longer metric...if you have a dremel..cut the length

Are you sure your friend use the correct lenght screws when he put the engine back togehter.
maybe he use the head's screws instead and they're a little bit shorter than the backplate's screws.

Are you sure they are strip...strip ?

You can try to re sit it and remove the rear needle valve bracket, so the screw will thread in a little bit deepeer.
and loctite the screws into place...
Maybe you can mount the rear needle valve bracket to the firewall or the side of the fuselge.

At the very least...a nice coat of JB weld.
Don't worry about the JBweld not being able to come off...it'll come off.
I sometime use JBweld for the carb and engine to prevent air leaks there for some magnum engines.
They weren't the purdies engines in the world with the JBweld but they ran good.
If you do a good job it won't look that bad.

theres still some treads deep in the case. I put the screws in without the back plate to see if they hit any treads. and they do without the plate, so I guess I'll get some longer screws for it. Do you guys know what size screw that is that fits it? I can always just take the engine with me.. thanks guys.

Do you deadstick because your going vertical? If so its not the engine its your pressure. Before you take off go full power and hold the aircraft vertically. If it dies on you its the pressure from the fuel tank all the way to the carb. Check for leaks. If not then you might have a cracked engine and you may need to send it in for repair.

I forget..I think it's #4 or #6...probably #4

Just get longer metric screws..from your LHS. They should have metric screws up the waazoo.
It's a bit toucher to find it at a harware store...you can look in those special tray section.
But i think I drove all over SD to hardware stores looking for metrix screws for R/C and they didn't have
the smaller sizes. Your best bet is probably your LHS. The owner might even have them in his personal tray.lol

Take one of the screws just incase and match it up

The engine mount screws for nitro RC cars are the same size.
They might be just what you need.

If they're long enough or lightly too long (with bracket). Just use washers right behind the screw's head.
This way it'll press against the bracket...you know what I'm saying.

Yes I got it . thanks flyx.

I had to send in my engine to Clarence Lee to install the coils for me. I kept messing up the hole and making things worse by the minute.
Things getting stuck in the prop: Let us not forget that neck strap we wear around our necks. I toss mine behind my neck whenever I'm starting an engine. I have never had this problem myself but saw it happen one day, it got ugly very fast.

its possible that your mixture screw sometimes known as the low idle screw is out of adjustment . if this is out of adjustment then the high speed screw becomes very touchy for getting the right mixture and the engine varies with different throttle settings. Check to see how many turns the mixture screw is out. if it is far from factory setting then reset the screw. to factory settings. I wasted about an hour dead sticking a friends plane until I decided to check on the low speed adjustment screw.

does anyone know what the setting for a 46fx should be for the low speed needle ? I dont have the book, bought it used.

I know that you, RCKEN are probably better than me but i would just like to say that i had 3 glow planes at the feild one day and it kept deadsticking on me and some one told me that it was probably the wildcat fuel, they said that their planes deadsticked on them whenever they used it to. so i went out and bought OMEGA fuel and none of my planes havent deadsticked since. it could be something that i did wrong but i dont think so because i didnt mess with the needle valve any after the fuel change. Or i could have just bought i bad gallon of fuel.

He DOES know what he is talking about....

I'd give more credence to a bad gallon of fuel than RCKen being off ( even when I disagree with him! ).

That's possible. Probably more likely is that that jug of fuel got moisture in it. That's exactly what will happen when fuel gets moisture in it. Engines just don't run right. Since the engines started running correctly when you switched to another jug of fuel I'd bet dollars to donut that the old fuel had water/moisture in it.

Ken

Now that would never happen would it??

Ken

Not that I know of!