Evolution Engines

It sounds as though you need to adjust the low end needle. It may be too lean.

I believe that they are all test-run and adjusted at the factory. They're supposed to have stops on them that keep you from running them too lean or too rich, I think.

There are now three lengths of plugs:

1. short-short: for small engines (0.15 and below?).
2. regular (the OS 3)
3. long-reach (same threads as the regular, but a longer snout on them).

The regular plugs should work OK, I think.

Good luck. Let us know what you learn from your experience.

Marty

Ted shuffled out of his cave and grunted these great (and sometimes not so great) words of knowledge:

With the engine "sputtering" then it dies on transition sounds like the LOW END is too rich. When you are looking at the side of the engine, move the limiter lever on the LOW end a LITTLE in a CLOCKWISE direction and try the transition again. If the low end is not set properly you will not get a smooth transition.

Evolution makes a pretty good engine (OS clone). They are more reasonable than an OS, and quality wise just as good. They are "supposed" to be broken in at the factory so little or no break-in is needed. (I like to play it safe and ran a tank through my 46 using the 2 minute rule. (Run the engine just below peak for 2 minutes, then shut it down and let it cool off, then repeat until the tank is used up.) If you do to RC Universe

and do a search in the reviews section, they have a review on the Evolution 46.

I like the OS #8 plug and use those in all but my 4 strokes. If they are the OS A-3 plug you should be OK with those, however, I would pick up some OS #8 when you get a chance. I have had no problems with my engine and it performs great.

OK! We now have one low end too lean and one low end too rich! Anyone want to toss in a third option? Low end just right is available! :)

Ted shuffled out of his cave and grunted these great (and sometimes not so great) words of knowledge:

When an engine dies immediately when the throttle is opened is a sign the low end is too lean. When the engine "stumbles or sputters", then dies is a sign the low end is too rich.

He states: "Every time I leave it idle (Which it does quite happily) then advance to full throttle, it dies. Occasionally is splutters a couple of times before it dies, other times it just quits, regardless of whether I have made tuning adjustments or not."

The spluttering makes me think the low end is too rich. If it just consistently died, I would agree with the too lean.

refer to Alan's Hobby, Model & RC Web Links

down to = "Engines,Plugs,Tuning, Petrol, Turbines, Mufflers, Cleaning, etc" sub section = "Carburettors, Tuning & Performance Testing, Glow Plugs" many sites, some with pictures - modern engines are really very easy to set up provided "O" rings on needles are good & carburettor is properly seated. regards Alan T. Alan's Hobby, Model & RC Web Links

yours is the best advice.

There is a surefire way to be certain whether the idle mix is rich or lean. Works every time, even works with Super Tigre engines where the manufacturers recommended method is complete B++**+ks and leads to grossly rich engines (not) running

Start engine and tune high speed needle Slow to reliable idle and allow a moment to settle to an even speed Pinch (shut) fuel line next to carb and wait.

Engines slows and dies. - Lean running Engine significantly increases rpm for several seconds before dieing- too rich

Engine speeds up slightly and then dies- about right

Repeat whole process from step one and it will be as near perfect as makes no difference. - probably be able to do it at a much lower idle speed this time. Once you have clear in your mind, engines cutting will be a thing of the past. Learn how to flush out fluff from a needle valve - the two together are almost the answer to all ills!

Make sure you know if you have an air bleed carb or a low speed mixture needle and adjust appropriately. If you don't know wat this means its probably easier just to ask someone to show you next time you are at the field.

Stu K

Has worked for me many times on engines ranging in size from OS FP 25c.in to ST 32cc

Thanks, Stu - that makes a lot of sense. I'd like to follow up on your suggestion of clearing the needle valve: what is the best way to do this?

stuart knowles wrote: > ... Learn how to flush out fluff from a needle valve...

Com'on Ted! Sarcasm!!!

The OP doesn't really need sarcasm. He needed a straight answer to his inquiry.

The bottom line, John, is that something's seriously wrong. Evolution engines are getting great reviews from everyone who uses them. They are supposed to be factory broken in and needles set. The needles are also supposed to have stops to prevent turning them much too lean or much too rich.

Since you're having the trouble you describe, and you've turned the needles the distance you say, then you might need to return the engine as defective.

Before you do that, however, check the fuel lines and tank thoroughly. If you have an inline filter, remove it. These little jewels cause all sorts of trouble. Filter your fuel from the supply container. Make sure your pressure line is clear. The centerline of the tank should be within 3/8" above or below the spraybar. The klunk should be at least

3/8" from the back wall of the tank. Blow some air through the carb, not through the fuel nipple, but in a reverse direction. Be sure your fuel is fresh and contains a castor/synthetic oil mix. This is best for ABC/ABN engines like the Evolution.

Good luck with it!

Dr.1

Thanks very much guys, a wealth of advice and I appreciate every one, I have printed them off, and am going through them in detail. it will be Saturday or sunday before I get back to the field, but I will let you all know how I get on. Again, thank you all very much for your help, good to know that there are people out there willing to help when its needed.

John.

The symptoms you describe sound like you are sucking air somewhere in your fuel system. The idle symptoms not being consistent point to that. A good indicator on the Evo is to look at the line that runs between the high speed needle and the carb. If you can see bubbles while the engine is at full throttle, you are sucking air and the engine is running lean. The inline filter could be the culprit or it could be a pin hole in one of the fuel supply lines lines. Have you changed the line that runs between the needle assembly and carb with a larger diameter line? I know someone who did just that and had the symptoms you describe. We could actually see the bubbles going into the carb. We used some small nylon zip ties where the lines went over the carb and needle nipples and the problem was solved until a new, smaller diameter line could be purchased. If air ingestion isn't the problem, something else is very wrong. The needles are pretty well set for most areas. You can also call Horizon Hobbies and their tech support line can help you out as well. Their customer service is great. I've had my Evo now for almost a year and love it. I even still have the original glow plug and it works just fine. In fact, I bought another Evo

46 for my Somethin Extra.

I dont know if it was mentioned but a loose back cover gave me fits for a while. It was apparently drawing in air at times. I noticed that the Evolution has very few pieces to the crankcase. Minimal places to leak. Good. Back covers arent always easy to get at so they may go unchecked.

When has that stopped anyone on this group?

Hello Lee,

I have found that if an engine is playing up, a quick carb clean on the field can be effective. The place that often gets missed is the fuel inlet which is directly adjacent to the needle valve. Take out the needle valve and plug a fuel filler pipe onto the inlet and flush with clean fuel, then PUT THE FILLER PIPE OVER THE NEEDLE VALVE FITTING and flush again so that fuel squirts out of the carb fuel inlet pipe (still with me??) If there is any contaninationin the fuel bottle, fluff, hair, and small fibres seem common, it often lodges in the carb inlet pipe which often causes an irregular strangulation of the fuel flow, 'upstream' of the needle valve, so that endless tweaking of the needle valve makes difference to the reliable running of the engine. it only needs a single hair in there to wreak havoc. there have been a few occasions when this has been a 'miracle' cure

I have a variety of engines, mainly two stroke, and an engine cut is a real rarity for me, the only engine that has ever beat me was an MDS 38 which ran beautifully upright, but just wouldn't be consistent when fitted inverted, I never did get it to work and couldn't fathom why. It is worth developing the skill for getting our engines to run, just keep a mental note of how much airframe damage is caused by engines cutting on take off or at other inoportune moments, probably accounts for more than three quarters of the total number of crashes. Its not rocket science. perhaps should add that I very rarely take engines apart, theres not much to see in there. If its full of crash dirt I would just flush it out with the head and back plate off, I don't pretend to know the first thing about engineering

Good luck with yours Stu K

I have the .45 trainer engine and the .46NT. First of all, Evos are no

OS clones. They have real chrome liners. As for plugs, just get the O

8 and be done with it. One thing about most engines, it is good to pu in a new plug after break in runs, even on Evos.

Both of mine are far easier to run and keep running than most OS .46 that I've seen or owned. The characterists of these engines are tha they are forgiving as far as tuning and fuel goes. Also, they develop lot of power.

As for idling, the crankcase loads up with fuel. Shoving the throttl forward floods the engine right away if it is adjusted too rich. I tuning is close, the sudden inrush of air will make it go lean for second or two and the engine wants to die. In either case, if an Ev won't take a sudden shove to full throttle, your tuning is off. Chec the low speed again. Check the high speed. Check your idle.

The manual for these engines mentions the fact that some locations wil require that the owner reset the limits on the engine. They giv instructions on how to do it. Sending a poorly tuned engine back to th manufacturer is not the best way to get your engine tuned. If you ar going to run glow engines, you have to learn to tune them or get buddy to do it for you.

I've flown my .45 close to a hundred times and it has never quit. I wa new and had some poor habits back then, and that engine just kept o running. The .46NT is almost as good. I think the .46NT is putting ou more power than a .46 FX. If you put the Tower Hobbies muffler on it you get a really screaming engine!

One last thing. Check your fuel. Do you leave it out in the sun all th time. Does water form on the inside of the jug? Does it have the prope nitro content

-- blwbl

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Certainly has never stopped you,

Malcolm