582 problems

[egp8111 7]

Hello All,

 

I need some of your collective wisdom on a 582 greyhead I'm trying to get sorted out.  Let me confess upfront that it's not on a KF or Avid but a Rans S7.  However as a loyal KFIII owner I hope you will be understanding.  ( I ended up owning this thing due to some reckless latenight web surfing and possibly a beer or two)  Heres the deal, the a/c had been sitting up for a couple of years.  It was running fine with about 125hrs. on it before.  We've gone through the motor, pulled the cyls cleaned the rings, decarbed, syned the carbs etc.  Now with the same prop and pitch it wont turn up past about 4800 rpm.  It also wants to run the water temp up past 180 degrees when taxing around.  The egts and cyl head temps are fine.  The radiator has been flushed and coolent replaced.  Anyone have any suggestions where to start sorting this out?  It starts and runs fine.

Good thing I have the old reliable Kitfox to fly. 

 

Thanks

 

EG

          

[1avidflyer 1983]

Not sure I'm on the right track but maybe leaking seals?  Did you try to pull the choke or pump the primer to see if the revs go up?  This is the first thing that popped into my head, so take it with a grain of salt.  By the way,  what do the plugs look like after this taxeing?  Black= rich   white or gray= lean.  Just when I'm about to hit the send button, I think of something else to say.....  Are you sure your tack is accurate?  Jim

[C5Engineer 1170]

How ironic I joined and posted over at Rans Clan today asking a question for something on my Avid. Any chance something is plugged up in the intake or exhaust? Water temp going up would lead me to believe there's high CHT's but it sounds like you have that covered. What's the oil in the gearbox look like? All things lead that the engine is overloaded some how... Bad bearing somewhere? I've never seen a two stroke run good but not make power if everything attached to is it working correctly. The saying is true they run best right up till when they quit.

[egp8111 7]

thanks,  plugs are a light brown.  I'll try the primer to see if it will bring up the rpm.  I was wondering about the tach, engine feels strong at full throttle but I dont have much to compare it to,(my KF has a 912)  I have a spare tach that I might swap out to see any difference.  Any ideas on cooling?  The radiator is hot after running the engine so the theromstat must be opening.  Do the water pumps go bad ?  How would you check.

 

wish it sounded as strong as Joey's in his video's ! 

 

EG   

[akflyer 1427]

Where is the radiator at? Mine didn't like taxiing around and would go over 180 till I dropped it down another 2" below the belly.

Any chance you put the pie plate on wrong? The first time I did mind it was by the book.. But the book shows it mounted upright, not inverted... Guess what this idiot here did... Yep, timed it wrong and it wouldn't run at first, I flipped the plate, offset it a couple teeth n it would run, but like yours, not make much power. Once I figured it out... With the beer... She ran great I dig the S7, lets see some pics of it! If I wasn't adding another kid to the mix anytime in the next few days, I would be looking for a rans instead of something with 3 or 4 seats

Check the tach... Are you going off an analog tach or a tiny tach?

[Av8r_Sed 82]

Did you take apart the carbs?  No junk in the bottom of the float bowls?  Take the carbs off and look through the main jet and you should be able to see straight through.  If it sat with gas in it for any length of time you might have crap built up in there. Old gas, especially auto gas doesn't age well and tends to gel.  Also if you have it apart, make sure it has the newer floats with the beveled edges.

 

Check out this article for further carb info: http://w.cps-parts.com/cps/pdf/Part52.pdf

[egp8111 7]

I bought it from the widow of the second owner. I talked to the originial builder and he said it ran and cooled well for the 90 hrs. he flew it. It had been sitting several years when I got it. We took the carbs apart and cleaned them. Im wondering if the cooling and power problems are related. It has a UMA tach but I'm going to swap it out for the old aerosport tach from the KF 582 days to see if there is a difference. The rad is on the bottom of the fuse. I'll try and post a pic.<br />Thanks everyone for their thoughts and suggestions.<br />EG<br />

[egp8111 7]

The latest info on my engine issues.  Changed tach guess what, shes turning about 6800 static.  I"ve repitched prop to bring it down to about 6200 static.  It will run fine about 140-160 degrees at 3000-4000 rpm,  I can run it up and down the runway with higher power but it wants to run the water temp up to 180 or so.(guage is right, I checked it against the kitchen therometer)   It will cool back down if I let it idle about 2300rpm.  Does that sound too far out of limits?  It should cool better in the air right?  It's mid 80's here today and humid.  Funny thing is the cyl head temp is about 150 or so and the EGT's are down around 850-900.  I'm sure that's telling me something but I don't know what.  No one around here knows sqwat about a 582 so I'm on my own.  I sure appreciate you guys inputs. 

I listened to the EAA's webinar on "Is your two stroke about to fail" but about the only thing I came away with is buy a new one every 400 hours and sell the old one.  Well I'm the guy with the old one!!

 

thanks

 

EG           

[Av8r_Sed 82]

On warmup, I get about to 185 on the water temp before the thermostat opens.  Then it varies between 170 to 180 while taxiing.  If I do a full power runup (eg when pitching my prop) I can get to 190 before backing down and cooling it off.  In the air I usually run around 170 in the summer.

 

Forget about CHT on a water cooled engine.  It doesn't mean much of anything.  In the air, I just watch the EGT's like a hawk.  I'm happy to have a HacMan system which allows me to dial in the correct mixture and EGT for most phases of flight.  Before I had that I had to avoid the mid-range RPM settings for the most part.

[Mendlerr 4]

sounds like a possible fuel delivery issue as well as another underlying issue?

[egp8111 7]

another vote for the Tiny Tach.  Third tach on my 582. max static rpm: UMA tach 4800 rpm, Aviasport Tach 7000 rpm, Tiny Tach 6250 rpm. They were all pretty equal until about 5000 rpm then the two needle tachs were off.   

[akflyer 1427]

I kind of figured this was your issue due to the low EGT's.  The only way the EGTS will be that low is if your running way fat on the jets (but then it would miss and blubber and the plugs would be black) or the prop is over pitched (do to crappy tach).  When the engine is happy, the EGTS will be around 1100-1150 on take off/ climb out and the RPMS on climb out should be 64-6500 for best short field/ climb and around 62-6300 for a better cruise speed.  If your prop pitch is too low, you may have issues with EGTS trying to go over 1200 in cruise.  It is a balancing act that the IVO inflight prop makes VERY easy to do.  With that said, its not too bad to get a ground adjustable prop dialed in to give you acceptable performance also.

 

Glad you got it sorted out!

 

[egp8111 7]

Thanks everyone for your help in getting my 582 sorted out. I flew the S7 for the first time today.  The engine ran great, all temps were well in the green. It was my first time behind a two stroke, I was impressed.  The engine was smooth and had plenty of power.  You guys really are a great resource and really helped get my confidence up in the motor. 

Now I have to decide between the KF and the S7 errrrrrr

 

 

EG   

[akflyer 1427]

Awesome! Glad this rag tag buncha miss fits could help you out! I have a lust for an s7 so I would lean that direction!