OS .46 la problems (Full Version)

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Eagle0424 -> OS .46 la problems (12/10/2012 10:29 PM)

Hi guys,

I recently received this motor and it wont start. it has never been run and is over 10 years old. Also, it threw a prop when i tried to start it with an electric starter.
What am I doing wrong?

Thanks in advance for any help.



DavidAgar -> RE: OS .46 la problems (12/10/2012 11:42 PM)

If it won't start, I would check for fuel flow to the carb and the glow plug. As for tossing a prop, that would indicate that it is getting fuel and might be locking up. Does the engine turn over with ease, or is it hard to move. If it is hard to move, put some fuel in it to loosen things up. Good Luck, Dave



mooseflier -> RE: OS .46 la problems (12/11/2012 6:05 AM)

I assume there's no grinding or anything when you turn the prop. That said, check the fuel as DavidAgar mentioned. A good way to do this is to open it up full throttle, put your finger over the carb to completely cover it (dip your finger in oil to make sure), then forcibly rotate the prop counter-clockwise to draw the fuel into the carb. Watch the gas line... does fuel come through the line after a few granks? If not, you likely have a leak... check your fuel and muffler line.

Also, if the engine is that old and unused, I would put some oil in the thing. Take the muffler off and put some oil in the muffler slit to get it into the piston. I use some great stuff called 'mystery oil'... I forget who makes it. But if you fly glow planes, you should always put some oil like that in the engine in off-season. I'm not as old as some of these folks, but I've had an OS .46asb for about 18 years that I cherish... I've lawn-darted it into the ground 2 ft deep, flown it in the rain, and wrecked it countless times, but if you clean them and oil them well... they last... at least 18 or so years =)



mike109 -> RE: OS .46 la problems (12/11/2012 12:31 PM)

G'day

The OS LA 46 is a great simple engine which is very suited to trainers.

If the engine is new then it needs a little running in before it will perform to its best. It may be difficult to start in this process.

If it threw a prop, that usually means that the engine had a lean mixture in the cylinder when you tried to turn it over (or a really rich flooded one).

This is what I would do.

1. Put it in a test stand or mount it in a piece of wood with a cut out to fit it. Use 4 nuts and bolts to secure it.
2. Mount a tank behind it so that the centre line of the tank is level with the carby. If it is too high it will flood the engine and if it is too low it will have problems drawing fuel.
3. Put an 11 x 6 prop on it so that when you turn it over anticlockwise (looking from in front of the engine) it comes onto compression with the prop at the quarter past 9 position.
4. With the tank full and connected to the carby, open the needle about three turns. This will be quite rich.
5. With a muffler pressure line from the fuel tank vent connected to the muffler pressure connection, open the carby fully, block the end of the muffler and turn the engine over several times by hand. You should see fuel come up the fuel line to the carby. When the fuel gets to the carby, turn it over a couple more times to prime the engine.
6. Set the throttle so that the carby is open about 1/32 inch or a little more.
7. Turn the engine over by hand to make sure it turns over freely. If it does not, it is flooded. Turn it on its side so that the muffler is lowest and flip the prop back and forth to try to clear the excess fuel into the muffler and drain it out. If you cannot get rid of the excess fuel like this, remove the plug and turn the engine over with the plug out. Be careful putting the plug back. Use your fingers to get the plug started or you may wreck the thread. Do not overtighten. About 1/4 turn after finger tight.
8. Attach a glow plug driver or 1.5 volt battery to the glow plug.
9. Turn the engine over with the starter. If the engine does not fire, it probably is too dry and needs more prime (Step 5). Else, the plug may not be glowing. Check by removing.

Once the engine starts, let it run rich for about a minute and then gradually close the needle. It will need about 10 minutes running before you try to fly it. Leave it tuned a bit rich for the first few flights.

But the best advice I can give you is to find someone who knows about these engines and ask for some real help. A local club is the place to ask.

Cheers

Mike in Oz






rlipsett -> RE: OS .46 la problems (12/11/2012 1:52 PM)

The manufacturer of the oil is marvel. the mystery oil is a penetrating oil for loosening stuck or rusted parts but there air tool oil is great for engine preservation since the mystery oil is not good for the seals



Gray Beard -> RE: OS .46 la problems (12/11/2012 3:45 PM)

Moose, why would he need to be putting Mystery oil in this engine if it rolls over? Just wondering, I use marvel for a number of things, I have just never used it to oil up an OS .46la?
Eagle, you have one of the best beginners engines ever made by OS. Do what Mike said in his last sentence and find someone that knows how to operate an engine and ask for some help.
If you can't do that then open the high speed needle about two turns out, take a straight pin and place it in the small hole in the carb and turn the screw on the side of the carb in or out until the hole is about half way open. That should get it running so you will be able to tune it. The carb is an air bleed type so it acts/adjusts a little back wards then most.



Eagle0424 -> RE: OS .46 la problems (12/11/2012 9:32 PM)

Thanks for all the help guys. Upon further inspection the motor was flooded when it threw the prop. Also, the the new plug I put in it was faulty. Now that everything is right it runs great. after one tank it turns an 11x6 at about 11500 rpm. Does that sound about right?



Eagle0424 -> RE: OS .46 la problems (12/11/2012 9:52 PM)

Anybody know about rossi motors? I have a .40 with what I assume is a tuned pipe it runs 12,000rpm with a 10x7, 15% nitro, and a hot plug. Comapared to other .40s that is good but I've heard a lot of hype about rossi and I expected it to be higher. Should I change anything?



mike109 -> RE: OS .46 la problems (12/11/2012 10:08 PM)

G'day

Glad to hear you got it going. The revs sound about right.

As for the Rossi, they really don't like a lot of nitro. 5% or none might be better. As for the revs, they were great engines but the only Rossi I ever owned was a 15. It screamed. I have heard some Rossi engines were timed to scream while others were more torque engines. Some one will chime in with some real info.

Cheers

Mike in Oz



Gray Beard -> RE: OS .46 la problems (12/11/2012 11:42 PM)

RPMs sound about right. I used the LA .46 in all of my fun fly planes and the prop I used the most often is the same as yours. Been a long time sense I ran one but 11 sounds like it's in the ball park. The LAs are just bushed engines and like Castor oil to keep the bushing from wearing. I used a lot of the .46 and always wondered why they bothered with the under powered .40. They finally quit producing the .40 but I still have a couple of the dogs from trainers I have been given. No need for after run oil in them either. The castor oil in the fuel will keep them lubed up. I always did dry run mine after use though to get rid of the left over alcohol. I just gave away the last one I had on hand and the new owner is happy as can be with it.[:D]



jester_s1 -> RE: OS .46 la problems (12/12/2012 4:45 AM)

If your Rossi really does have a tuned pipe it probably peaks closer to 15-16k rpm. So it will need a prop that lets it turn probably 14k on the ground to ever get into its power band. A colder plug may improve your top end power a bit. Hot plugs are usually for making an ornery engine idle and transition better or for making an engine with lower compression run well with no nitro fuel.



jaka -> RE: OS .46 la problems (12/12/2012 7:59 PM)

Hi!
12000rpm with 15% nitro using a 10x7 prop (what brand) is not particularly good!
An ASP .40 Mk11/Kyosho .40 turns a 10x7 RAM prop at 12700 rpm on 80/20 fuel (Nova Rossi 4 plug and both head shims removed).
Same rpm does a Webra .40 GT using the same fuel and prop.

The old Rossi engines do not like to be lugged down with "big " props! Use smaller 9x6 or 9x7 APC props instead.



Eagle0424 -> RE: OS .46 la problems (12/12/2012 10:11 PM)

Thanks for all the help guys. I will definitely prop down and may experiment with plugs and fuel in the rossi.
btw the os .46 la keeps getting better
[8D]



speedracerntrixie -> RE: OS .46 la problems (12/12/2012 11:51 PM)


quote:

ORIGINAL: Eagle0424

Anybody know about rossi motors? I have a .40 with what I assume is a tuned pipe it runs 12,000rpm with a 10x7, 15% nitro, and a hot plug. Comapared to other .40s that is good but I've heard a lot of hype about rossi and I expected it to be higher. Should I change anything?



A 10X7 is too much prop, 15% nitro is too much nitro and you have the wrong plug. These are the 3 main components to ignition timing in a glow engine. What you are doing is the same thing as advancing the ignition on a car engine to the point of pre-ignition. I bet it's getting really hot!   What you need to do is put on a 10X6, an OS #8 or Enya #3 plug and if you want to use the 15% fuel check for a head gasket of around .015 to .020. The correct setup on that engine should get you in the 15,500 to 16,000 range where that engine wants to be run.




mooseflier -> RE: OS .46 la problems (12/13/2012 4:02 AM)

Hey GreatBeard... it was the fact that it hadn't run in years... with an engine like that I would always lube it up first. Normal use of that oil is for storing it, but still, something that old usually needs some oiling. Or at least I think it can't hurt. Sorry to be so vague before.



jester_s1 -> RE: OS .46 la problems (12/13/2012 4:34 AM)

Actually he's probably not advancing the ignition or running hot. You have to remember that the mix adjustment has a big influence on ignition timing as well. If he's at a peak setting, he's gone rich enough to retard the ignition back to the point where he is still making max power for his setup. The problem is that with that setup that max mix setting is too rich to produce the best burn, so he's losing power. Going to a colder plug and less nitro or less compression will retard the ignition, letting him run a leaner needle setting, thus getting his mix closer to optimal for power while still having the ignition timing right.



speedracerntrixie -> RE: OS .46 la problems (12/13/2012 4:48 AM)

I disagree. You have to remember that especially  the older Rossi's are set up with high compression in order to operate on low nitro. Running them with higher nitro then 10% will increase combustion pressure and cause the engine to fire too early. running a hotter plug will make it even worse, running too large a prop will create even more heat and pre-ignition. In my earlier post I reccomended some specifics for prop size and glug heat range. Where do you think I got that information? I got it from using Rossi engines in my race planes for the past 3 seasons, I have gone through the learning curve with them and was fortunate enough to win a season championship with them this past season. Obviously I know what it takes to get them to perform correctly.



jaka -> RE: OS .46 la problems (12/13/2012 3:57 PM)

Hi!
Speedracerntrixi !
You are right! How do I know? 30 years in pylonracing![;)]



speedracerntrixie -> RE: OS .46 la problems (12/13/2012 11:50 PM)


quote:

ORIGINAL: jaka

Hi!
Speedracerntrixi !
You are right! How do I know? 30 years in pylonracing![;)]


Jan, I may have a couple years on ya. My first Q-500 race was in 1979. No worries, we can't all agree all of the time. I beleive there is some merit to what you are saying but IMO what you are refering to is a symtom of what is happening and not the actual cause. I agree that he is not able to lean the engine to optimum fuel/air ratio but I feel it is because of the pre-ignition. As he leans the needle the cylinder temps go up, the engine pre-ignites and sags so he does have to run rich. Yes this contributes to the low RPM figures. The fix is to lower the cylinder temps via less load and lower plug temp. This will make the engine fire at the correct time allowing him to lean to the optimum air/fuel mix and get the engine into it's correct powerband. This is provided someone has left the stock head gasket in place. We have all seen guys that remove head gaskets thinking it will lead to more power and then wonder why they burned up a piston and liner.




jester_s1 -> RE: OS .46 la problems (12/14/2012 12:25 AM)

speedracerntrixie - I don't think we actually disagree. I understand what you are saying about those factors advancing the ignition. My only point was that as one richens the mix it doesn't stay advanced; the mix affects ignition timing too.



speedracerntrixie -> RE: OS .46 la problems (12/14/2012 12:30 AM)

Agreed the extra fuel will cool the engine enough to retard the timing but obviously kills power. Looks like we are in fact on the same page.



Eagle0424 -> RE: OS .46 la problems (12/14/2012 4:52 AM)

Hi guys!
Just some info that might help.
The rossi has an os #8 plug and is actually using a 10x6 prop.
And It is definitely running on the rich side. I haven't had a chance to look at it recently but am pretty sure there is no head shim. When I get the chance I will run it and tell you all what happens.

Also, should I stick with the plug it has in it or swap it out?
I know a couple have said to change props but what should I go to or should I just leave it alone for know?



jaka -> RE: OS .46 la problems (12/14/2012 7:58 PM)

Hi!
What prop size you choose depends on what plane you intend to use the engine in.
10x6 (RAM or Graupner G-Sonic is the best) is for low winged pattern type planes.
9x6, 9x6,5 or 9x7 (APC) is for Q-500 type planes (130cm in span weighting 1,6-1,8kg).
11x4 is for fun fly type planes!

The Rossi .40 is/was as standard equipped with a head shim. I would use no more than 5% nitro and a Rossi 3 or 4 plug. (Nova Rossi 4 or 4A is also good chosies).
Enya 3 or OS 8 will work good too.



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