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582 Best Idle Speed

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Posted

582 Mod 99 Owner Manual says idle speed = 2000 rpm.

I've manually set and sync'd my carbs to 2000 rpm idle. On a cold engine, I start and warm-up at 3000 rpm which is nice and smooth. Once warm, I can generally drop rpm to about 2600-2700 before I get into the really rough stuff. Pulling back to 2000-2100 rpm still seems pretty darn shaky though. I know some have set idle at 1600-1800 rpm to slow approach, but is the engine any smoother idling there when sitting on the ground?

thx

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Posted

582 Mod 99 Owner Manual says idle speed = 2000 rpm.

I've manually set and sync'd my carbs to 2000 rpm idle. On a cold engine, I start and warm-up at 3000 rpm which is nice and smooth. Once warm, I can generally drop rpm to about 2600-2700 before I get into the really rough stuff. Pulling back to 2000-2100 rpm still seems pretty darn shaky though. I know some have set idle at 1600-1800 rpm to slow approach, but is the engine any smoother idling there when sitting on the ground?

thx

I havent got my plane finished yet but the previous owner of my 582 said he set the idle around 2200-2300 RPMs.My gearbox is a 3 to 1 ratio with a 68 inch 3 blade prop.My brother-in law has his set about 2400, anything less and it shakes like hell.Im thinking seriously about putting a clutch on mine so I can idle it down to where it should be.Randy

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Posted

Hmm, 2200-2600 rpm is the 'no-no' range on mine where you would swear the whole thing is coming apart. If I couldn't throttle back below 2700-2800 rpm I think I would smoke my brakes or just float along forever on a 3-pt landing. Pulling back from the 2200-2600 rpm range to 2000-2100 rpm smooths it out notbbly, but it is by no means as smooth as at 3000 rpm. I'm sure it all becomes second nature, but as a 2-stroke newbie watching for and trying to compensate for this 'no-no' and lower rpm range is distracting. I just wanna chop the throttle!

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Posted

Hmm, 2200-2600 rpm is the 'no-no' range on mine where you would swear the whole thing is coming apart. If I couldn't throttle back below 2700-2800 rpm I think I would smoke my brakes or just float along forever on a 3-pt landing. Pulling back from the 2200-2600 rpm range to 2000-2100 rpm smooths it out notbbly, but it is by no means as smooth as at 3000 rpm. I'm sure it all becomes second nature, but as a 2-stroke newbie watching for and trying to compensate for this 'no-no' and lower rpm range is distracting. I just wanna chop the throttle!

Doug, Do you suppose that the prop could be having a balance problem? The 582 that was on the C model I had, had a clutch, but when the prop began turning at around 2300, it was very smooth.

Seems like there were several conversations on the yahoo site regarding balance, might be worth the research.

On another topic, when Randy and I switched the wings from his Mark iv to his fat Avid, and he continued rigging the controls, he found that the controls to the ailerons were reversed if you routed the cables from the "v" bracket under the pilots seat to the side of the fuselage that it was pointed towards. Have you discovered this yet? Live and learn I guess.

Jack

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Posted

Hi Jack - I'll search through both the Rotax or Avid Yahoo Groups. I am guessing it's not a prop balance issue though, because it does run smooth as silk at ~2800 rpm and above. My engine, gearbox and prop are all pretty new, each ~60hrs with no history of problems since install in the logs. All three blades track, take and keep pitch perfectly and I can feel when the bug guts accumulate and throw it out of whack. I suspect my old style bed mount may be contributing to the problem and want to try one of the newer style side mounts. Even with the new style mount. however, I see many 582 posts talking about that 300-500 rpm 'no-no' range. Range might be a little diff on each depending on engine tune, PSRU and prop, but it's widespread and certainly no secret. I am really torn about using the clutch, great for floats but glide path of a brick. Now I need to check the FatB, lol!

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Posted

Hi Jack - I'll search through both the Rotax or Avid Yahoo Groups. I am guessing it's not a prop balance issue though, because it does run smooth as silk at ~2800 rpm and above. My engine, gearbox and prop are all pretty new, each ~60hrs with no history of problems since install in the logs. All three blades track, take and keep pitch perfectly and I can feel when the bug guts accumulate and throw it out of whack. I suspect my old style bed mount may be contributing to the problem and want to try one of the newer style side mounts. Even with the new style mount. however, I see many 582 posts talking about that 300-500 rpm 'no-no' range. Range might be a little diff on each depending on engine tune, PSRU and prop, but it's widespread and certainly no secret. I am really torn about using the clutch, great for floats but glide path of a brick. Now I need to check the FatB, lol!

Yep, much to check, much to research. When I flew with an instructor in the C model, on base, he had me reduce the power to only 4ooo rpm, nice normal decent for landing. It kept the prop rpm about where a direct drive 4 stroke is at idle.

Jack

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Posted

I have the old bed mount on my mod 1 with 582 w/clutch c box 3-1.

There is no vibration at any rpm. Clutch comes in @ 2200.

As far as glide ratio, thats only a problem if the motor is not running,

and by then thats not your only problem.

I had the same thoughts before buying the clutch, but weighed engine outs

against problems vib can cause and nuisance factor for "every" engine start

and the clutch won hands down. Especially after flying with akflyer w/clutch.

Bob

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Posted

Do you have a B or C box? Sounds to me like your too rich on the idle. On the ones with out a clutch, I have set the idle at 2-2200 to keep it smooth. mine I can idle down to 1650, but I have a clutch. On my buds Mk IV it would shake like a bitch when cold and you would get gear box chatter under 2500 or so, but once warmed up a little, she would smooth right out and you could go to 2000 no problem. do you have mixture enricheners? it is possible that they are not closing all the way and you are getting rich on the low end, OR your air screws are not set right. Turn them out about 1/8 turn each and see what she does.

:BC:

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Posted

Leni - I have a C-box w/ 2.62:1 ratio and my prop is currently set to give 6000 rpm on static run up, so I know I am running slightly rich... on purpose. Until I get real familiar reading this 2-stroke engine, I figure plugs are cheaper than engines. My carbs are plumbed with primers and enricheners (choke), both appear to be working properly. Cable routing etc. looks good

What I've done: manually leveled the carb tops then, using the carb slide stop screws and top cable adjusters, sync'd the carbs to provide for both slides to open, reach top WOT, and close simultaneously. I am using the stock 11G2 Jet Needles w/ clip in the 3rd notch from the top and my idle air screws are backed out 1 full turn, all just as recommended in the Rotax jetting chart for my +500 ASL. One thing I can not verify yet as I haven't dug far enough into the carbs, is what Main and Idle jets I have in there. I strongly suspect they are the stock 165 Main and 55 Idle jets as the engine is quite new and there are no engine logbook entries (unlike a few entries showing a temp install of 15K2 Jet Needles and experimentation with clip positions when trying out a new GCS 2-blade prop).

Almost everything I have read suggests that replacing the 55 Idle jets with 45's makes a huge difference at 2000 rpm and lower idle speeds. Some have tried 50's but noticed little difference and had to go lower, many say skip the 50's and go straight to 45's. Some have even had to go to 40's but sounds like the safest and most cost effective plan is to try the 45's first so that is probably what I will do if I find the stock 55's inside. In any event, assuming the issue of prop balance has been addressed, the overwhelming comments point to this idle jet issue as the best place to start. That, plus using an electronic carb sync vacuum meter vs. manual sync seem to generate the best results. Sooo, now I'm looking for a meter...

Bob - Since floats will be a permanent fixture starting next year, I'll probably try a clutch if I can't find a cheap jetting fix to smooth things out. I am slowly warming to the idea but, ughh, more $.

Randy - Do you still have that 582 side engine mount sitting around?

tnx

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Posted

Leni - I have a C-box w/ 2.62:1 ratio and my prop is currently set to give 6000 rpm on static run up, so I know I am running slightly rich... on purpose. Until I get real familiar reading this 2-stroke engine, I figure plugs are cheaper than engines. My carbs are plumbed with primers and enricheners (choke), both appear to be working properly. Cable routing etc. looks good

What I've done: manually leveled the carb tops then, using the carb slide stop screws and top cable adjusters, sync'd the carbs to provide for both slides to open, reach top WOT, and close simultaneously. I am using the stock 11G2 Jet Needles w/ clip in the 3rd notch from the top and my idle air screws are backed out 1 full turn, all just as recommended in the Rotax jetting chart for my +500 ASL. One thing I can not verify yet as I haven't dug far enough into the carbs, is what Main and Idle jets I have in there. I strongly suspect they are the stock 165 Main and 55 Idle jets as the engine is quite new and there are no engine logbook entries (unlike a few entries showing a temp install of 15K2 Jet Needles and experimentation with clip positions when trying out a new GCS 2-blade prop).

Almost everything I have read suggests that replacing the 55 Idle jets with 45's makes a huge difference at 2000 rpm and lower idle speeds. Some have tried 50's but noticed little difference and had to go lower, many say skip the 50's and go straight to 45's. Some have even had to go to 40's but sounds like the safest and most cost effective plan is to try the 45's first so that is probably what I will do if I find the stock 55's inside. In any event, assuming the issue of prop balance has been addressed, the overwhelming comments point to this idle jet issue as the best place to start. That, plus using an electronic carb sync vacuum meter vs. manual sync seem to generate the best results. Sooo, now I'm looking for a meter...

Bob - Since floats will be a permanent fixture starting next year, I'll probably try a clutch if I can't find a cheap jetting fix to smooth things out. I am slowly warming to the idea but, ughh, more $.

Randy - Do you still have that 582 side engine mount sitting around?

tnx

I still have the engine to firewall mount but I dont have the 4 mounts that go with it so you would have to get them from Kitfox.If you need the mount let me know.Randy

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Posted

I still have the engine to firewall mount but I dont have the 4 mounts that go with it so you would have to get them from Kitfox.If you need the mount let me know.Randy

Thanks, I'll research to see if M-III and M-IV firewall stations are the same and send you a PM later.

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Posted

Doug, PM me your addy if you want and I can have my kid send out my electronic carb syncro if you want to try that out. Just pull your primer lines off and put the vacuum lines on those ports.. It is the Carb mate one that Calif. Power sells (among many other places I spose).

Yep, Idle jet.. Running rich leads to more issues than plugs.. Set the prop so you can turn 6500 on take off or you are leaving alot of performance on the table, and you are working that engine a good bit more than you really need to. It is harder on it to lug it down, that to let it rev to where she makes the most power.

:BC:

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Posted

Way to rich on idle Doug. You can't really burn it up by being too lean at idle. I'm running far leaner idler jets than the stock jetting chart calls for and I still have my air screws backed out 3-4 turns to get a smooth idle. Like Leni said...too rich leads to more things than fouled plugs...it leads to carbon build up which leads to stuck rings which leads to engine failure. First thing I'd try is screw your airscrews all the way in and then back them about 3-4 turns. Don't go too far or they will fall out...ask me how I know... If you cannot achieve a smooth idle this way you need to get a smaller idler jet.

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Posted

Thanks Joey, I think I'm starting to get a handle on how to go about troubleshooting the mixture setup. I'll back the idle jets out as far as possible and see how that goes. I did see another warning about not going too far

Leni - thanks for the offer but I'll check my local resources first. Probably not real good to have the shipping monkeys tossing your fine calibration equipment around. I may even check out purchasing my own, certainly seems like a worthy expense if it doesn't cost a left nut.

I can't help but chuckle at how many Rotax owners have gone thru this shuffle. This must be funny watching from the cheap seats.:lmao:

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Thanks Joey, I think I'm starting to get a handle on how to go about troubleshooting the mixture setup. I'll back the idle jets out as far as possible and see how that goes. I did see another warning about not going too far

Leni - thanks for the offer but I'll check my local resources first. Probably not real good to have the shipping monkeys tossing your fine calibration equipment around. I may even check out purchasing my own, certainly seems like a worthy expense if it doesn't cost a left nut.

I can't help but chuckle at how many Rotax owners have gone thru this shuffle. This must be funny watching from the cheap seats.lmao.gif

Let me know if you need it. It is never funny when your watching someone struggle to get the engine running right... Unless you are one of those guys that refuses to take advice from others who have gone before you. Then we get to :lol: as you end up doing what was suggested after you do a complete rebuild, buy new carbs, and shake the airframe and gear box apart trying to monkey with it before actually doing what was suggested :lmao:

:BC:

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Posted

I just look at max tuning as part of the 2-stroke learning curve and my type 2 personality says it's safe as is but can still be improved. I got a buyer coming to pick up my Jab on Sat. and after getting into this Rotax sh*t, letting the 4-stroke go ain't gonna be easy.

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:lol: 4 Strokes have their own issues... So what you gonna put in the nose of the fat bastard? I know the feeling.. Just cause you think it is OK now does not mean it cant be better right? One of my race buddies thinks that to get the most out of his sled, he has to lean out the main jet till she burns up, then go one size fatter :lol: He does not listen to us about plug reading etc, or look at what we are running, he would rather burn down on a practice lap, then work like a mad man putting on new jugs and pistons before the race.. I think he just likes to show off how quick he can swap jugs :lmao:

:BC:

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