Powder coat is quite a bit thicker than paint and may inhibit heat transfer from the fins. I'd do some research before powder coating the fins. The crankcase should be fine though.

Jack

Powder coat! Wonderful stuff but not fuel proof and questionable in high heat situations. Wounldn't use it on an engine.

Rich

Ive never even read the instructions or anything yet.I do know your suppose to bake the powder at a certain temperature in an oven but ill have to look it up.I would think that after applying and heating and hardening up the powder it would take the heat from the cylinder.Ill have to look.
If not,i guess it would just be crankcases or whatever anyone else wanted done.
Maybe case and hub?

I have an FS74. Where can I get the prop hub adapter? I plan on trying the gas/glow mix.
Thanks, MikeB

Ill have to see if i have one made up or have to make one.Do you plan on using the center out of the flywheel or do you need one made up for that.
Or are you going over the whole shaft?

I really don't know. I won't need the flywheel. I do like the looks of the type that cover the whole crank end. Does that answer your question?
Thanks, MikeB

This is where i do not know for sure what to do. what is the best way to go?

I recieved your email and responded.Are you sure there left hand threads?

I do have one that fits over the crankshaft,it right hand threads and or 8x1.25.Is that what you have.There the same as an echo.Ill send a pic in a PM.

crank is 5/16 diameter, 20 threads per inch, left hand threads, no taper

I finally got the FS80 put together and on the test stand. I put a set of Bowman rings in and cleaned it up. Mixed up a batch of gas oil about 40 to 1 and put a 16x6 MAS prop. I got 8100 RPM on it which I thought was ok but it still lacks compression. Maybe the rings will take awhile to seat with the Chrome cylinder??? I think I'll try a bigger 17x6 or 16x8 to 10 and see if it pulls the same-could be it just won't rev any more than that based on the porting. Lite engine with OK power though.

Maybe your cylinder is not round (concentric), any scoring???

Nope! Perfect shape, I think it needs more than 10oz of fuel run through it?

Hmm, what type of coating is in the cylinder?? or is it sleeved. I'm not familiar with this engine. You might have to take a scotch pad and mildly scrub the cylinder, depending on the coating. Once the rings color (usually black) is gone, they are seated.
Ten oz's of fuel is not much, but usually, especially with two rings, you have decent compression right off of the bat.

I agree with two rings it should be good quickly-scotch brite pad wouldn't do a thing, 600 wet paper will hardly touch it. It may be designed with the this compression.

Dont scuff,sand or scotch brite a chrome cylinder. The chrome is a hard surface needed to prevent the rings from wearing out the cylinder. The rings will wear to the chrome not the other way around.


Jim

I thought I would bring this thread back. I have a stihl 25.4cc engine. I picked it up a long time ago from a shop. I ran it this spring on gas glow, and it seemed like a strong engine. I forgot my tach that day, so no readings. It screamed with an 18-6 and it sounded strong with a 18-8. I have stared at this engine many times pondering what rpm it was actually doing. I have an XYZ CDI that was originally supposed to be for my poulan, but I cant resist the urge to test this engine. I have the ignition all set up, and by tomorrow the JB weld will be set up. I need to get a different spark plug as well. I would have just tried gas glow again, but I have been addicted to burning avgas. I just love the smell of it when it burns, and also the fact it doesnt stink up my apt. I will post a video if all goes well tomorrow.

Guyscan you help a novice out with a conversion question. It's a Stihl 25CC that I bought from a guy that had already had the conversion mostly done. The only think I had to do was complete the spacer between the carb and the engine. I did as was told and dremmeled out a little channel to allow air or fuel to pass. The engine will run fine for one flight then it bogs down like it's not getting fuel on subesquent flights. It has a walbro carb but twisting the needles has very little effect. I cleaned out the filter screen but no better. Last weekend, I made a new gasket but have not run it yet. My question is, what is that spacer for between the carb and engine? I need to get another prop also. The engine is in my 1/4 scale cub. What is a good prop?

Greg

Greg,
The spacer is a heat sheild for the carb-they don't like heat. Also make sure the small hole in the spcer line up with the carb. This is a pulse hole that creates the pressure to run the diaphram in the carb and pull fuel from your tank. This must be correct to get it to tune properly. Sorry if i stepped in.
16x8 prop should be a good start

Thanks Frenchie. I can run a pin through the hole into the engine but I don't think it lines up perfectly. I may need to enlage it just a tad. Will that have negative effect? I made the gasket out of a manila file. What gasket material do you recommend?

Greg

The material used i believe is called G-3??or 7-Garolite. It is expensive and hard to work with but why don't you just get the stock manifold or have one made. Maybe some other will chime in.
The pulse hole should be a 1/16th to 1/8th in diameter. Make sure that it is free flowing and sealed off from the main carb and outside air.

G-10 is greenish fiber glass looking stuff for higher temperatures than the G-7

Never seen G-3

Ya your right, G10 is it, I couldn't remember the numbers. G3 ???? summit i suppose.

I see that the 56cc unit says Mahle on the cylinder.

Finally got something done. Thanks to my Uncle Byron for the stainless muffler. It turned out real nice. I will test run it once the hull is completed with all running gear installed.