My prop adaptors have a .375” steel stud with 5/16 thread on the outboard end. A 5/16 self-locking nut is used to secure the prop.

Bill

Thanks. Just to not misslead anyone, on the fourth photo you can see the aluminum prop nut. As a matter of fact there are two nuts for the prop. There is a high-grade steel hex nut to hold a prop and the aluminum prop-nut is used just to lock the steel one. Aluminum prop-nut was turned inside for the outside diameter of the hex nut, and the depth of just a bit less than the height of the hex-nut. So the steel-hex nut is kind of hidden inside the aluminum one.

The steel threaded part of the prop-shaft is made by cutting off the head from the high grade machine screw and set in the hub with green loctite.

Rysium: Very nice work!!

AV8TOR

I fired up a poulan 42 today on gas/glow. Using a carb that I think came off a Poulan 46. It's a WT 285. Site says it is 13.49mm. All I have is 15% nitro/18% oil total synthetic. Used that and mixed according to earlier advice here. Tried a couple props. A MA Classic 18x8. Turned 8000. Then went to a APC20x10W. Turned 6650 to 6700. Going into a CMP Katana 140. Already balanced out fine. I think once I figure out the best starting procedure it will work out fine. Hand started and used a starter both. Transition is good and idle is smooth all the way down to 1700. This is showing some real promise. Hats off to you guys that worked on this!!!!!!!!

Eagle flyer: What does your 42cc engine weigh? Thanks Capt,n

It's on the test stand now. When I take it off I can weigh it. I want to use an inferresd temp gun to check my glow plug temp. Any body know what it should be checking in that manner?
Thanks

Glad that it worked for you buddy, later you may try to thinker arround with the portings if you wish to get more power (RPM's) out of that baby I know that it will fly that katana very well, let us know your test flight results!!!!.

31cc ryobi with glow plug adapter ,original zama carb, 10% glow fuel ,mixed 1/3 glow 2/3 premium gas, ( glow fuel is pretty old ) , runs with heat on but is surging to full rpm's and falling off then surging to full rpm's again; all across throttle setting, from idle to high speed. switched back to magneto ign. and runs fine ( very rich but no surgeing) in addition when on glow/gas wants to backfire and run backward sometimes resulting in prop hub kicking off :any suggestions????

P.S. I have been running this engine as a gas/oil with magneto and it performs well in this mode total time on engine is maybe 5 hrs.

My first thought is it might still be too lean. Sometimes we have to raise the diaphragm lever in the regulator a touch to get a little more pressure and richen them up across the range. Are you using a four stroke glow plug??? And then there's that "old" glow fuel...

Good luck,
AV8TOR

Cal45 - sounds too lean to me and I suggest you get a larger carb. The original carb is too small for any performance. Suggest an 11 mm or 26/64" walbro.

More info, I am leaving the glow driver attached so that the plug will stay red hot, & I had tried richer settings on low and high speed needles; won't run at all with carb set at rich settings ???????????????

I think the first thing then would be to get some fresh, 10% oil and 10% nitro glow fuel to try. One can spend hours working a problem like this, only to find it's something simple like the fuel, which you mentioned was old.

Have fun,
AV8TOR

try lifting the lever underneath the diaphragm, right now is to lean, also check the screen filter on the pumpside of the carb see if it's dirty

Now I'm a believer!!!! Had some fresh 15% mixed it up and runs great idles good and makes good power on top end,have 2 stroke plug in now so it died when I pulled heat off, and still not as clean as pure gas (oil residue) but what the heck, I will try a four stroke plug , and even if i have to use an onboard glow driver I will still shed the flywheel and coil weight and that is a big weight savings. Av8tor you were right it was the old fuel
P.S. I scored 3 gals of 10% nitro/10%oil powermaster at lhs Thanks for yall's input
P.S.S. No modifications of carb were needed and needle settings were close to what they would be for gas

I wouldn't celebrate just yet. The engine is dying when you remove the booster battery from the glow plug. Something still isn't right.

I'm with someone else that suggested that you check the screen that filters the fuel. Surging is usually a sign insufficient fuel flow.

Glow fuel doesn't go "bad" unless you leave the cap off for hours at a time, or let it catch sunlight directly. I doubt that was the cure. Nitro helps any engine, so that part of it was a possibility. These low compression utility engines will burn just about any flammable liquid without protest. I have ran mine on Coleman Fuel. It doesn't get much worse than that.

I'm still trying to figure out the fascination with this mode of running a gas engine. Let's see, you take a perfectly good running gasoline fueled engine and then you ruin it? <G>

OH WELL....

I will give you 2 very good reasons. LESS WEIGHT......NO IGNITION GLITCHES...case closed. Capt,n

"Let's see, you take a perfectly good running gasoline fueled engine and then you ruin it? <G>"

Maybe we have different definitions to what Ruined is.
Adjust Carb, Add weight (replace plug & ignition parts).... run gasoline again.... I fail to see the ruined aspect, seems like it was a gas engine that can be setup for glowplug and reset back to gas. The Glow works without having to grind the mounts. As ruined as chalk ruins a chalkboard.

If what you meant is Degraded rather than ruined, that depends on your scale of standards and priorities
----Weight, Interference, Cost of Fuels, Power
Would you lose 2lb if it cost 10rpm drop? What about lose 1oz if it cost 1000rpm drop. Clearly there is some point in the middle where it is RPM cost effective to lose weight. And that is a personal opinion/preference. Same with LBs vs FuelCost.

You already asked this question here: [link=http://www.rcuniverse.com/forum/fb.asp?m=4353673]http://www.rcuniverse.com/forum/fb.asp?m=4353673[/link] and got at least 2 answers. Which part didn't you get

Hmmm, last night I told myself I wasn't going to get into it again.... But...

Besides all the benefits of less weight, no ignition interference, etc., all my engines GAIN a few hundred rpms on gas glow, start much easier than with gas/ignition, and idle much smoother and slower.

I think maybe Artisan is one whom has had lots of problems with glow engines, (kind of like my brother), and therefore thinks using a glow plug is "ruining" an engine. Personally, the only problem I ever had with glow engines was having to clean the gook off the plane afterwards. Not a problem with gas/glow. It's kind of like having the best of all worlds!

AV8TOR

--------------


These guys are burning 1/3rd regular glow fuel mixed with their gas/oil mix. That's why it works.

Just finished reading this whole thread......

Looks like if you took a Moki glow engine and installed needle bearings it would run well on this two parts gas to one part 10% nitro/10% oil mix. But the oil would probably need to be 100% castor in that engine.

What got me to this thread was what oil would mix with E85 and how ould are gas engines run on it?

I meant to say a 10% nitro/ 10% oil glow fuel blend.

Guess you missed the part where I experimented with E-85. It won't work. The E-85 is 85% alcohol, but the alcohol is ethanol, not methanol. The glow plug needs the methanol to work. After lots of experimenting by all of us here, the best mix is 10% oil/10% nitro glow fuel, mixed with high test gasoline. 1 part glow fuel to two parts gasoline. That glow fuel is commonly sold as fuel for Super Tigre engines, by nearly all the large glow fuel suppliers.

Good luck,
AV8TOR

You could very easily use it on a big bore engine (Super Tigre, Moki, Magnum etc.) but you will need to use at least 5% oil without having to replace the brass bushings for needle bearings, as a matter of fact they are currently brewing a special glow fuel for the supertigre big bore engines which contains only 5% oil, that means that a big bore glow engine can safely run on 5% oil, the only thing I would change on a glow engine it would be the carb, I would adapt a walbro carb to make it run better. So my suggested fuel combination would be to take a regular 10% nitro plane fuel (18% oil) and mix it 1 part glow fuel wit 2 parts of 92 octane gasoline at the end it will result the following mixture:
Nitro: 3.33%
Oil: 6.66%
Methanol: 24%
Gasoline: 66%
This mixture should work very well on a Moki or other big bore Glow engine without any further interior engine modifications.

Not always You can read back this thread and [link=http://www.rcuniverse.com/forum/fb.asp?m=3134961]in post 156[/link] I wrote about running Poulan 25cc on straight gasoline/oil mixture (no methanol). Glow plug powered all the time, and the engine performed better then with original magneto (and was almost a pound lighter).