hardnut

Hi all
i have a SC 46 2-stroke glow engine which i have inverted in a p40
its starts great and with a 4 stroke plug will run (idle) until the tank runs out . The problem is when i come to start it the next time the plug is always bogged down with the little fuel that must be left in the engine ?? and then of course i cant get it started, i do use after run oil every time i have finished with plane for the day is there any way of stopping this or do i have to remove the plug ever time i have finished to make sure there is no fuel left in the engine
rob

P47Tbolt

My Feedback: (20)

when starting it,put the plane on a stand inverted if possible.That way the fuel that has accumalated in the glow plug can
run out.put your glow igniter on it and start it.

TedMo

Using the after run oil is probably why the glow can't light. I have never used it and have no complaints about any of my egines in any way. To each their own though.

hardnut

Thxs for the help
TedMo how long have u been running glow engines without using afterrun oil ? this is only my second glow plane so allways thought it was needed but if i dont then i will try without
thanks p47tbolt for the idea [sm=teeth_smile.gif] never thought of that one so will try that tomorrow hopefully that will do it and someone has said about storing it upside down as well so will try that

many thx for the help
rob

jetmech05

I stopped using after run oil as well.....are you having trouble starting after every flight or just the first flight of the day? if it's the first flight of the day then I'd say the after run oil is the problem.....if its every flight perhaps you can try a spray bar glow plug.....good luck

hardnut

Jetmach05 its just the first flight(start) of the day after that its fine no problem at all

well ive tried a 4 stroke glowplug in it yesterday and well 40 minutes of idle without 1 stop so i think thats great now will have to try it again as didnt add afterrun oil this time and have stored it upside down so will wait and see fingers crossed
many thxs for all yr help

rob

bkdavy

My Feedback: (1)

I would question why you're using a 4-stroke plug. The four stroke plugs are much hotter than the normal two stroke plugs. With the engine running, this will cause earlier ignition timing, cause the engine to run hotter, and reduce you're power output. Running a hot 2-stroke plug like the OS A-3, with proper tuning on the low end, should give you a perfectly reliable idle. You'll probalby have to lean out the low end a little, but at the low end it won't hurt the engine. The engine doesn't really care if its inverted, sideways, or right side up.

My experience with after run oil was that the ARO fouled the glow plug and reduced its working life significantly. Morgan Fuels (Omega and Cool Power) claims to have corrosion inhibitors in the mix, and ARO is not needed. So I don't. The only bearings I've had to replace are bearings that were going bad on used engines I purchased.

Brad

Mode One

If you run a two stroke inverted, the after run oil, un-burned fuel and oil is simply going to collect at the lowest point of the engine, the glow plug cavity. There is really nothing you can do about it except remove the glow plug between flying sessions. I don't mount two strokes inverted. I know people do and have luck with it, to me it's a complication I am going to do without.

I have used and will continue to use afterrun oil! I have had no problems with doing so and have seen no shortened glow plug life. I have, on the other hand, had to replace bearings because I forgot to use it and stored the engine for a couple years. I use a 50/50 mix of Marvel's Air Tool Oil and Automatic Transmission oil. Been in the hobby for many years and this has worked well for me.

JRFisher

The after run oil is your problem for sure.
I have an OS 46 FX that's probably 10 years old and its still running fine. Never saw a drop of after run oil. However it probably is a good idea to use it if you are going to be storing the engine for a while. I wouldn't know about that. I fly as often as my schedule allows.

Mode One

"The after run oil is your problem for sure".

That's a pretty hard core declarative statement to make! JRFisher, Are you running your engines inverted? Hardnut is specifically stating this is a problem he's encountered because of running his engine inverted. In referance to what I said above, I have been using After Run Oil for 40 plus years without issue! I have no problems with you guys deciding not to, I feel it's a good idea from my perspective. I do so because of my experiences both in the hobby and as a person who has made a living from machines his entire life.

Hardnut, a good test would be to not use After Run Oil when quiting for the days flying session, then see if the problem occures the next time you go out to fly.

jetmech05

Mode one...I'd bet the after run oil is the problem...after all the glow plug becomes the low spot in the motor...the oil would puddle in the cavity around the coil....keeping the coil cooler than normal......
kinda the same thing that made recips smoke so bad on starts...all the oil running into the lower jugs......

hardnut

Hi
thanks all for the ideas ,Mode one i will be trying the engine tomorrow and as i said before i havent put afterrun oil in it so will have to see but i will use aftrerun oil if im going to store it for abit
if thats the problem then thats fine
Bkdavy i have spoken to many people and shops when ive been to models shows and most of them said about using a 4 stroke plug in a inverted 2 stroke as the plug doesnt get hotter it just heats up quicker so doesnt go cold because of the fuel. i have tried them and they run,idle very well and engine doesnt overheat

so many thxs to all for your help
will try tomorrow

rob

ktreadway

I have had engines for many years and they never saw any after run oil. I really see no benefit in it. Maybe if you were going to store it for several years. Also you may want to consider a on-board glow driver. Takes care of alot of problems with inverted 2- strokes.

Mode One

Hardnut, Did not using After Run Oil cure your problem?