Veraster

A few weeks ago I posted a thead where I was trying to get my new engine to start. You all were very helpful. I eventually got it to start but became busy and wasn't able to work on it any more until recently. The thing that kept it from starting is because I didn't have the throttle on "idle". It was maybe 1/3rd and I thought that was idle.

Now that I can start it I have a whole new problem. It wont stay on all the time. Sometimes it will stay on until I try to open the throttle past 1/3rd or so. It will also start backwards right after I prime it and run loud and steadily like it seems it should minus the fact it's going the wrong way.

I have tried messing with the needle vavle. If I turn it more than 1/2 a turn leaner or richer than the 1 and a half turns it says in the manual, it wont start and if it's running, it dies.

I'm using 15% nitro fuel and this engine: http://www.hobbypartz.com/72p-s61aii.html

So should I put on the propellor the other way? Should I touch the adjustable screw close to the carb? I dont know what to do but I know one of you guys know what im doing wrong or what I need to change.

Steve Percifield

My Feedback: (14)

I'm sorry, but it's really tough to diagnose engine problems this way. You need to seek out a local club and find their engine expert to help you. hands on works best.

jester_s1

As I recall from the thread about having trouble starting the engine, it's already been said that needle valves have absolutely nothing to do with starting. Starting is all about the prime. You can start a properly primed engine with both fuel lines disconnected and it will run for a few seconds. If you engine won't start, it isn't primed right. Tweaking the needles to try to get an engine to start right is an exercise in futility.

That said, I've never seen an engine that won't start on a good prime and run steadily at full throttle unless it was too lean to run or had a bad air leak. Get it started, then leave the glow driver on and run it up to full throttle. If it dies, then richen the high speed needle just 1/8 of a turn and try again. When it does run at full throttle steadily with the glow driver off, tweak the HSN until you get a noticeable increase in rpm when you pinch the fuel line for a few seconds. That indicates a rich top end which you want for the first two tanks of fuel through the engine. Once that is set, you start tuning the low speed needle to get the best idle and transition you can. There are plenty of detailed guides on RCU on how to do that, so there's no need to type it out again here. If that procedure doesn't work, it's likely you have an air leak either in your fuel lines or carburetor o ring, or you have loose bolts on the engine somewhere or (rarely in a new engine) a bad front bearing.

tschuy

My Feedback: (1)

what is the engine size and type... Sounds like the needles are way out of adjustment and need to be set to the manufacture settings as a starting point. Given the limited information posted here, there could be several issues with why the engine is not running the way that is should. Tank position, fuel feed tubing size, plugged ports on the carberator and many others.


Lets start with the engine size and manufacture... This will be helpful with getting a reference point for some research... Also list where the engine came from and any information if the engine experienced a crash. Has it ever been taken completely apart?

Send some responses to the above question and I'm sure some help will come your way.

oskartek

If you are anywhere near sea level or within 2000 feet, 1 1/2 turns out on the high speed needle
is too lean, go to 2 1/2 to 3 turns out and go from there.

Happy flyin'  Oscar 

larrysogla

Maybe this will help, it is rather long but very effective, but don't forget to read the last paragraph about clogged muffler pressure fittings....."Too often, I see newcomers to our hobby ask online how many turns do I set my needle valves, or I messed up the factory setting, how do I setup my low end needle so I can start my engine? Here are some great tips to make you an expert engine tuner.

How to setup the needles so you can get your engine started:

Start by opening the high end needle about 4 turns from fully closed. This is just a starting point to ensure the high end needle valve isn't restricting fuel to the carb so you can adjust the low end needle setting.

The low end is easily set to a good starting point with the following procedure:

Close low end needle valve completely.

Install a clean piece of fuel tubing into carb fitting, make sure it is long enough for you to blow into it with your mouth.

Open carb to 1/5 open from closed position

Blow into fuel tubing while slowly opening up the low end needle valve. Stop turning low needle valve when you first feel air blowing into carb from your mouth or hear the sound of air blowing into carb. The flow should be restrictive and very small. We only want a small amount of fuel to flow (air to flow) at 1/5 throttle opening. This low end needle setting will get your engine running and may require further adjustment. THis is just a ball park setting.

Now close high end needle valve and open carb to full throttle. Blow in fuel tubing and simulataneously open high end needle until you have FREE FLOW of air into carb. You should not experience as much resistance to airpressure as you did on the low end. Your needle valve should be open between 2-5 turns (it all depends on the carb folks).

This procedure gurantees you don't have a blocked carb or closed needle settings for low and high. This will get you in the ballpark which then will require you to fine tune your low end and high end for best performancehighly recommend the pinch test .

Pinch test procedure:

First start engine this way:
Prime engine by opening up throttle to full and blocking exhaust with finger. With blocked exhaust, rotate engine until fuel just enter's the carb-watch fuel line to see fuel displacing the air in the fuel line.

Remember the following rules about needles:

1. Low end needle affects the mixture below 1/2 throttle for most engines. Use it to adjust the idle and the transition from idle to full throtttle.
2. High end needle affects mixture above 1/2 throttle. Adjust it so engine is running 300-400 rpm shy of max lean rpm at wide open throttle.


Reduce throttle from full to about 1/5 throttle opening. Apply glow ignitor and rotate engine (hopefully w/ starter) counterclockwise (for 99% of all engines out there) until engine starts. When engine starts, move throttle to 1/2 throttle and then remove glow driver.

If engine won't start, try more throttle until it does. If engine will only start above 1/2 throttle, it means your initial low end needle setting was too lean. Richen it about an 1/8th of a turn until the engine starts at a low throttle (1/5 throttle) setting.


If engine will not advance to 1/2 throttle w/ glow driver is on then leave at 1/5 throttle with glow driver until engine is warmed up-about 2 minutes should do the trick.

Advance throttle again to 1/2 throttle slowly. If engine dies then your low end needle is probabably too lean. Richen by 1/10 increments.

Once you can get your engine running at 1/2 throttle then its time to remove the glow driver/ignitor. With ignitor removed, advance throttle to full throttle. Chances are your engine will be too rich and may even quit. If so, briefly pinch and release fuel line as you advance to full throttle to verify the mixture is too rich. If it is too rich, then in small increments lean it out until it will run at full throttle without quitting. This does not mean the high end mixture needle is set. This is just a starting point to ensure your engine is running at wide open throttle (WOT) so you can make the proper adjustments.

With engine running at full throttle, slowly and carefully lean the high end needle valve until the engine is spinning at its max rpm. This can easily be determined by sound alone-no tach needed. This is where engine is producing most power but the mixture setting will cause the engine to run too hot and overheat. So, as a safety feature, always richen the mixture about 300 rpm shy of max lean rpm. Verify this by briefly pinching and releasing the fuel line to the carb. If the pinch test causes the engine to speed up and back down, then you have correctly set your high end needle setting. If engine doesn't speed up much or dies then you are still to lean and need to riche the mixture slightly until it passes the pinch test.

You are almost there. With high end needle setting set about 300 rpm rich of max lean rpm, recheck idle and transition. Let engine idle for 30-60 seconds and then snap throttle to WOT. If engine hestitates in the transition, fine tune mixture so that the transition is snappy and idle is reliable. I personally like a lean idle mixture so I can idle for long periods without fuel pooling up in the crankcase which causes stumbles when transitioning to full throtttle. You can also use the pinch test when the engine is idleing. Pinch and hold fuel line with engine at a fast idle. Engine should speed up and die about 4 seconds. If it takes longer, your low end needle is too rich, if it takes less time or if your engine dies instantly, you are to lean and need to richen your low end needle.

Once low end needle is set, you will probably never have to adjust it again. However, your high end needle should be checked before every flight by doing the pinch test at WOT to verify the mixture is slightly rich. This 5 second test and adjustment, if necessary, will gurantee you a reliablie engine that will last a long time. Our carbs do not adjust for changes in temperature, humidity, barometric pressure, etc... and a small change of 5 degrees in temp can cause a properly tuned carb to be out of tune and possibly too lean (or too rich depending on whether it gets hot or cold outside).

Hope this essay helps the newcomers to our hobby and prevents them from becoming one of the set it and forget it crowds that do not benefit from optimum tuning for the best engine performance and longevity out of an engine."...........
Now,that is good advice. Also check with another NEW glow plug recommended by the manufacturer or ones that work very good with others with the same engine as yours here in RCU. I would also try NEW fresh fuel. Also and this is SO IMPORTANT.......poke the muffler pressure fitting with a paper clip to unclog any carbon clogging or restricting the pressure fitting...a clogged muffler pressure fitting will cause all kinds of throttle and transition problems and it does not take long for the exhaust contaminants to clog up that tiny hole. 'Nuff said.

Gray Beard

My Feedback: (-1)

In post #2 Steve mentioned finding a club so you can find a mentor or instructor. Give it a bit of thought. People trying to get advise and learn how to operate an engine on a web site are doing thngs the hard way. Out at the field I can usually teach two stroke engine gas or glow in a very short time. It's very easy but without seeing and hearing what is wrong with an engine it may never happen. Go find a club in your area and get some hands on instructions. It really is the best way to learn how to do these things.

carrellh

GB,
Finding local help, including a link to a club in his area, was mentioned in the other thread.

Veraster

I swear that this engine wont start if my needle vavle is set more than 2 turns open if it's cooled off and hadn't run in the last 2 minutes. However, I did manage to get it to start on 4 turns open after I took a heat gun and heated it up real good. This was only after I was about to give up and this was the last thing I was going ot try before giving up for the day. After I heated it up, it started on the first try.

With the needle valve as far open as it can go, my engine still stops after about 1/2 throttle. When it starts going the opposite direction, it runs louder and seems to run better. So I thought i'd turn the propellor the other way and see how that went.

I was so so close to getting to what I thought would be the thing that finally works. 2 months or so of hard work and it was finally going to do something right. I tried to losen the hex nut holding the propellor. It was kind of stuck. So I took a clamp and held on to the metal ring that's behind the propellor and everything which is the only thing that I thought was part of the shaft. (picture below). I tried to losen the nut. Well that metal thing came loose!! Oil had leaked under it and made it come off. tried to clean everything off with degreaser once I got the propellor off (by putting a nail in the piston inside the engine so it would temporarily stay). No matter how hard I tried I couldn't get it to become clean enough to go on and stay on so I could tighten anything.



WHAT DO I DO NOW??? Order a new engine?

JohnBuckner

My Feedback: (1)

The reason the propellor was difficult to remove was most likely you or someone turned it on without reaming first.

While I am not a fan at all of Magnum/ASP/SC engines. However I do have a few various ones that were successful but I watch a lot of folks struggle with them.

You asked, what do I do now? My suggestion is to network and find a local hands on experienced mentor to help you with your engine woes. You can only do so much through these forums and you need help.


John

Veraster

Ok. I' sending an email to my local club now.

EDIT: after internet research and hours of messing with it, the bottom line is that the threads on my engine's shaft are gummed up to such an extent it's impossible to screw anything on there especially with how it leaks oil and there is no possible way of getting it to ANYTHING like that. Im really mad. Is it possible to fix that?

JohnBuckner

My Feedback: (1)

What does the threads gummed up mean? Are they damaged? Yes threads that are actually damaged from say crossthreading the prop nut on (its usually the nut the gets the worst of it) can sometimes be repaired easily by running a 1/4-28 die or threat chaser over the shaft.

Oil leaking from the front bering is normal to some extent. This is not an issue.

John

pimmnz

I notice you said that you used a nail to lock the piston by putting it through the exhaust. This engine is now unserviceable. The nail will have left a small indentation and burr on the liner and piston. Any motion of the piston will have scored it and rendered the piston and liner unserviceable. At the very least you will be up for a replacement piston/liner set. You were advised to seek help at a local club, now you know why. If the prop nut is the long nut in the photo you should know that this is not the standard nut and appears to be one purchased after market for fitting a spinner with a centre bolt. If this nut is aluminium it will explain why it was tough to remove, the threads are probably deformed. You should have a plain steel nut and a thick tapered washer retaining the prop. You will show wisdom by stopping any further attempt to operate this engine and spend your time seeking help from a real person living somewhere near to you who knows how to repair and operate miniature two-stroke engines. Seek help and listen and watch.
Evan, WB #12.

jester_s1

We probably should have left this thread at Steve Percifield's post #2 and let that be it. The OP would have been a lot better off.

But since we've started it, we might as well finish it.

First off, there is always oil on the prop shaft and prop washer (the big aluminum thing that came off). Oil is not a problem. If the prop washer won't tighten back down and stay then either something is missing or broken.

Second, you may or may not have ruined your piston and liner with that nail. Either way, that's the wrong way to do the job. A properly fitting wrench on the prop nut while holding the prop to keep the shaft from turning would have gotten it off just fine.

Third, engines are designed to turn in one direction. The only way your engine is going to run better going backwards than forwards is if you have confused which way it's supposed to turn in the first place. To be sure we are on the same page there, the prop should rotate counter-clockwise if the plane is flying toward you.

Fourth, and I don't mean any disrespect in saying it (I've been there too), don't try to jerry rig or halfway do the hobby. Even thought it's recreational this is aviation, and doing things right is necessary whether it's a commercial jet or a wooden model. Don't try to make a tool work that isn't right for the job, and don't try to get out of buying things you need. A cheap used electric starter and a good new battery would have already saved you hours of frustration- well worth the cost. Using the right tools and doing it the right way will bring you hours of enjoyment from the hobby. Trying to get creative to make your equipment do what it wasn't made to do will bring you hours of frustration.

Fifth, be wary of used items. I don't recall you saying where this engine came from, but it's entirely likely you just acquired some other former noob's mistake. Seasoned flyers often have good used items for sale that they simply have lost interest in, but until you really know how to spot the good stuff you are just asking for trouble. When you figure up the hours you spent messing with this engine vs. what it would have cost to buy a new Thunder Tiger that likely would have worked on the first day, you'll probably find you haven't made even minimum wage in the savings.

Now that you've learned some of the new flyer lessons the hard way, get some local help. I know it will require time and energy and possibly some money to do it but I promise you it will be cheaper and less time intensive than trying to pull this off by yourself using nothing but internet advice. A competent instructor is worth at least one complete airframe in the crashes he'll save you, not to mention the hours upon hours of frustration dealing with issues like yours that are likely a common problem that could be diagnosed by an experienced ear in just a few minutes.

pimmnz

You will also have to look carefully at the shaft just in front of the front bearing, does it have a flat area on it? If it does it lines up with a flat on your prop driver (that silver thing in your fingers). I do not see a flat on this driver. You have either ground the flat off trying to remove the prop, or it has a taper inside the driver. If it has then there should be a tapered collet on the shaft, which I cannot see. I can also see what appears to be a crack on the rear face of the driver, probably caused by the destruction of the flat inside the driver. If you have exerted enough force to damage the prop driver as I have described, then you have also damaged the piston/liner with the nail. I will repeat my previous request, do nothing more with this engine, get help from a real person, and learn all you can from him. It will cost a bit to get this going, but you will be much wiser.
Evan, WB #12.

jaka

Hi!
From the picture I can see that the engine probably is an ASP or Kyosho GX (same manufacturer).
You have to use a suitable glow plug like the OS 8 or Enya 3 ,but there are other as good too! 5-15% nitro fuel and the right size prop is vital (10x7,11x6,12x4 if a .40 engine) (11x6,11x7 12x4,12x6 if .46 or .52).

All engine need to be adjusted to run right!
You start the engine at idle (throttle drum open aprx 1,5-2mm). When the engine starts you Emidiately give full power and adjust the high speed needle to near max rpm!!!!

Then throttle down! The engine should maintain a steady idle at around 2000-2500rpm...if not adjust the low speed needle!

The prop should be fastened by a spinner nut! Preferably one in aluminium! See to that the treads on the axle are clean before you mount the prop!

Ed Smith

The tapered collet is stuck in the prop driver. The "Crack" is the split in the collet. Pointless me adding any more to this subject.

Ed s

pimmnz

That'l be what it is. OP needs to find someone close by who knows.
Evan.

speedracerntrixie

My Feedback: (29)

Sadly at this point the OP has destroyed the engine. This is going to come off harsh but may save the OP some frustration and money. Not everyone is cut out for this hobby.

jester_s1

We don't know that the engine is destroyed anymore than we know how to fix his problem. Chances are his troubles are the result of a simple issue that an experienced engine tuner will find in about 2 minutes. If the threads on the crankshaft are truly damaged, they can be fixed with a threading die. Air leaks can be fixed with new gaskets and o rings and tuning issues can be fixed with an experienced ear.

Gray Beard

My Feedback: (-1)

I didn't see an engine that was destroyed but I do see someone that is in dire need of some hands on help. Most any modeler could probably have the engine fixed and running in no time but if the OP doesn't get to someone that can be a hands on instructor this may not be a good hobby for him. There is a big learning curve and most of us have all had a mentor or 6 to teach us things hands on. When it came to engines I had a great one nd several not so great but I did learn over time.

speedracerntrixie

My Feedback: (29)

I admit that what I am saying is not encouraging at all. The tuning aspect I can see. Nobody is born with the knowledge on how to tune and engine. The fact that a screwdriver was inserted into the exahust port while a pair of pliers were taken to the drive washer shows a lack of mechanical understanding. The piston most likely has a gouge in the crown now. I don't even want to venture a guess on how he damaged the threads on a hardened steel crank. I mean no ill will towards the guy but at some point one has to question if he has what it takes to succeed at R/C or worse yet might he injure himself or someone else?

jester_s1

Point taken that the OP has been a little reckless in working on his engine, but we all had that period of time when we were so anxious to get into the air we jumped into working on things before we bothered to find out how. At worst, he has messed up his piston which can be fixed with about $40 in the RCU classifieds for a replacement engine.

Gray Beard

My Feedback: (-1)

Most of my glow engines were given or traded to me, all four strokes. Some of them were in pretty rough shape and others were brand new. I wish I had the pair of OS .91s I have right now that a friend gave me. I did have to rebuild them both. The thrust washers were so chewed up from my buddy strong arming them with pliers I couldn't locate the timing marks. I run into this a lot.
Using a plier as a piston stop isn't a real bright idea but I have seen it done on a number of two strokes over the years. The gouge will cause the engine to not run at 100% but unless it is a huge dent the engine sghould still run well enough to keep the OP happy. As a kid I just tore into my Cox engines figuring therre was nothing I couldn't figure out inside one. When I got into RC as an adult I was wise enough to buy some books and find a mentor.
The hope is the OP learned something from this and will find an instructor or start looking for some good books?