Cylinder Mismatch?

Balogh
You’ve provided just what I wanted though not a direct solution to my problem. I’ll get this figured out yet. So, many thanks are owed for your taking the time to respond.
All the best…
Dave Mo

No sweat Dave, I enjoy engine discussions and sharing experience...what was your takeaway from my guesswork?

@DaveyMo , I am being more speculative, but the Medallion is considered the poor man's Tee Dee. It has excellent suction feed. I saw @Cribbs74 running his hopped up Medallion .049 on bladder pressure, was able to fly the pattern on his C/L Baby Clown (same wing area as Ringmaster Junior). But, may be the forced feeding help to put more fuel down its throat so it could breath more efficiently with the greater intake bypass capacity of hotter porting like your #1 and #5 cylinders with subport induction.

I think that for others to help, they need to know more details on the exacting environment that these engines have attempted to operate on but failed. (i.e., shimming of glow head, type of glow head, exact mix of the fuel you are using, test setup, tank height, length of fuel line, height of tank with respect to venturi needle, etc.)

IMO, there is no rocket science, and once you discover the factors causing your starting problems, can be on the way to having your engines run successfully.

Got on the back burner a Medallion .049 conversion to muffling by replacing the single bypass port cylinder and SPI piston with a R/C Bee NOS non-SPI dual bypass and exhaust throttle muffler (same with silicon rubber cover. So, when I do, don't anticipate problems, but will know more when I get there. (Just got too many irons in the fire, now.)

Hello

My takeaway from Balogh’s follow up is that poor fuel might be the problem. Most other bases have been covered. Tried the go juice on three motors and no luck at decent runs or even good starting. The motors were two Golden Bee’s and a Wen Mac 049.

Will get a new batch of fuel, give it the ol’ college try and then report back here. At that point if things are still in the doldrums, I’ll take GG’s advice and lay out the particulars on these three mills. GG: the 049 Medallion is one fine motor in my book!

Much obliged, good brethren.

Dave Mo…

Hello again:

Had good success with one of the double-ported Golden Bees. I tried new fuel and an electric starter. Of the two variables, I really think the problem was in trying to hand start the beast. Even with the electric starter I had to figure out a routine that worked. Will try the older fuel tomorrow after my nerves settle down. The successful run was with a full tank on a very tail-heavy Baby Flite Streak. Oh, was that interesting!

Thanks all. I'll be back with reports on the other two mills.

Dave Mo...

PS: My electric starter is a little homemade job fashioned from a Dust Buster motor and PVC pipe. It actually works.

D...

Good to hear you finally managed it with an electric starter. (Is the compression of the engine OK?)

In order to prevent excessive wear of the crankcase nose when cranked with a starter, a steel or phenol washer is placed between the prop drive plate and the nose. I am not sure if the Golden Bee has that or not. Also, an overprimed engine is prone to hydraulic lock and this may damage the piston conrod or break the crank pin, if forced by a starter.

I therefore add the washer for engines that I start with electric starters, and bump the starter then release the start button before the cone touches the prop spinner, and the engine is cranked by the inertia of starter rotor only. Safer than starting with current running constantly through the starter.

Don't know if you know this but we have instruction / start procedure manuals where it says INFO >   https://www.coxengineforum.com/h24-instruction-sheets   Trouble shooting > https://drive.google.com/file/d/1iNo75W7RzPkE4QDKCHwa1ixYhbhjiYSq/view  Just saying everybody here will help though it may take time and there is alot of good stuff in there too .

Balogh:

Yes, the motor's compression is very good. I don't intend to rely on the electric starter as I hope to learn the best routine for hand starting (don't want to damage the engine). I'll be careful to avoid hydraulic lock as I saw what it did to a connecting rod in a Norvel at the AMA event in Oshkosh a few weeks ago. Thanks.

Getback:

Hey, that is a great collection of info sheets! Thanks for mentioning it, and many thanks to whomever did the work on getting them into format.

Dave Mo...