RK clutch and idle RPM

[herman pahls 9]

Leni

I am now a believer in the clutch on my 582 and wish I could have used one those 12 years with a 532.

So smooth and no engine or gearbox shake or rattle.

Problem is that with the idle speed screws all the way out (and slack in the throttle cables) and with

# 50 idle circuit jets I am only 3/4 of a turn out on the mixture screw to get a 1900 RPM idle.

The more I turn the idle mixture screw out the cleaner the idle and the higher the RPM and the prop starts turning.

How did you get a 1400 RPM idle?

Rotax Rick said I need to file on the slide to let it drop lower.

Did you have this issue and how did you solve it.

Awhile back you said you could hand prop a clutch with a few screws.

Do you mind elaborating.

Thanks Herman

Edited 14 Dec 2011 by herman pahls

[BryceKat 125]

Herman,

I don't have the rk clutch, but i can get a 900 rpm idle verified by my tinytach. I use an Inflight adjustable prop set at a very fine pitch to get that. That same pitch gives 6800 rpm wot. Good luck, Bryce

[herman pahls 9]

Herman,

I don't have the rk clutch, but i can get a 900 rpm idle verified by my tinytach. I use an Inflight adjustable prop set at a very fine pitch to get that. That same pitch gives 6800 rpm wot. Good luck, Bryce

Bryce

I was also able to get a low idle without the clutch.

The prop has a lot of drag even at idle.

Thanks Herman

[herman pahls 9]

Are there any other RK 400 clutch users besides AKflyer?

He must be out of reach to answer my questions.

I just installed a clutch on my 582 Bluehead powered Kitfox and am very pleased.

I would like to be able to turn my idle speed down to 1400 RPM like he does and need to know how to modify the slides to accomplish this.

Also, my water temps are in the 195-200 range on 50 degree days at sea level.

I am using the stock Kitfox under belly radiator.

I tried lowering it by 1 and 1/2 inches as I have seen others do with no improvement.

I used the same radiator 4 years ago on a 532 and had to block 1/3 rd of it off this time of year to get up to 165 degrees.

Maybe the radiator needs to be overhauled or the 582 Bluehead runs hotter.

I am using the orange GM style antifreeze at 50-50.

The CHT's are 275 max and the EGT's in the low 1100's at full throttle and 6500 RPM straight and level.

Any suggestions?

Thanks Herman

[C5Engineer 1170]

Are there any other RK 400 clutch users besides AKflyer?

He must be out of reach to answer my questions.

I just installed a clutch on my 582 Bluehead powered Kitfox and am very pleased.

I would like to be able to turn my idle speed down to 1400 RPM like he does and need to know how to modify the slides to accomplish this.

Also, my water temps are in the 195-200 range on 50 degree days at sea level.

I am using the stock Kitfox under belly radiator.

I tried lowering it by 1 and 1/2 inches as I have seen others do with no improvement.

I used the same radiator 4 years ago on a 532 and had to block 1/3 rd of it off this time of year to get up to 165 degrees.

Maybe the radiator needs to be overhauled or the 582 Bluehead runs hotter.

I am using the orange GM style antifreeze at 50-50.

The CHT's are 275 max and the EGT's in the low 1100's at full throttle and 6500 RPM straight and level.

Any suggestions?

Thanks Herman

Herman did you burp the cooling system? Maybe you have air in the bypass someplace. You also may want to pull the thermostat housing a take a peak.

[herman pahls 9]

Joey

Very good point.

I did not even think about burping the system.

Now I remember years ago on the 532 removing the temperature sensor on top of the head when initially installing the coolant to make sure no air was trapped.

Thanks for the suggestion.

Herman

[ChrisBolkan 130]

I have a question about the clutch. I've heard they are the bee's knees for float operations for obvious reasons. However, I've also heard that in the event of an engine out the prop freely spins, which I have been told cuts your glide about in half when compared to a stopped prop.

Am curious if you have any first hand experience with a stopped prop vs a free spinning prop and the effect on glide.

Thanks!

Chris Bolkan

[herman pahls 9]

Chris

I only have a few hours on the 582 and the clutch and flew with a Jabiru 2200 for the previous 4 years.

I had the same concerns regarding engine out glide but could not stand the gearbox and engine rattle and shake.

So far I have not noticed a radical reduction in glide angle if any when power is reduced to idle.

I am still in the testing stage being new to the 582 and have not started short field flying yet.

As I have already said, the 582 operates so smooth with the clutch I would not go back to flying without one.

I like the clutch so much that I would consider making a prop brake system if the glide becomes a problem.

Hope this helps. Herman

[akflyer 1427]

I have a question about the clutch. I've heard they are the bee's knees for float operations for obvious reasons. However, I've also heard that in the event of an engine out the prop freely spins, which I have been told cuts your glide about in half when compared to a stopped prop.

Am curious if you have any first hand experience with a stopped prop vs a free spinning prop and the effect on glide.

Thanks!

Chris Bolkan

my best glide on floats gives me about 750 FPM sink. Wheels I can get around 650. The two times I have had an engine out, I would not have bitched if I could have stopped the prop and gotten a better glide.

A test I know of was two guys side by side in cubs. At the same altitude they pulled the mixture. One guy pulled the nose up and got it slow enough to stop the prop, then went to best glide. The other guy just let the prop windmill. The stopped prop made the beach no problem, and the other guy had to restart to keep from getting wet and cold and loosing the plane.

With all that said, I will roll the dice and keep my clutch. We all gotta go sometime, I figure since the other half wont let me die in bed with 6 of her closest girl friends, I would just as soon head west in the plane. I try to not put myself in a position that a couple hundred FPM would be a deal breaker. If I have the terrain to allow extreme low level flight I do it. If there are no options to set down and keep it in a couple major pieces, I get a lil more altitude under my dumb ass.

[akflyer 1427]

Are there any other RK 400 clutch users besides AKflyer?

He must be out of reach to answer my questions.

I just installed a clutch on my 582 Bluehead powered Kitfox and am very pleased.

I would like to be able to turn my idle speed down to 1400 RPM like he does and need to know how to modify the slides to accomplish this.

Also, my water temps are in the 195-200 range on 50 degree days at sea level.

I am using the stock Kitfox under belly radiator.

I tried lowering it by 1 and 1/2 inches as I have seen others do with no improvement.

I used the same radiator 4 years ago on a 532 and had to block 1/3 rd of it off this time of year to get up to 165 degrees.

Maybe the radiator needs to be overhauled or the 582 Bluehead runs hotter.

I am using the orange GM style antifreeze at 50-50.

The CHT's are 275 max and the EGT's in the low 1100's at full throttle and 6500 RPM straight and level.

Any suggestions?

Thanks Herman

Funny you should post this one up.. I had the same issue last week. I have been flying with the belly radiator for a couple years with no issue. A couple months ago I had my brother move my plane off the lake and up onto the tundra when the water started getting stiff. He let it warm up as usual, but he said it quickly overheated when he put the coals to it to pull it up onto the grass. I worked on it last saturday and she warmed up as normal, then as I started to taxi onto the lake she blew anitfreeze all over.. Sumbitch.. So I send him to town to get more anitfreeze and I went to work pull the thermostat. It was fully open (as it should have been, she was pretty warm). When I stuck it in the snow it shut as it should. I re-installed and filled it back up. I ran it on the ground for awhile after I refilled the system and watched it cycle perfectly! Temp would hit 150 or so and she would open and go to 130, close, hit 150 then back to 130.. I knew the thermostat was doing its thing. I took off and did a quick lil turn around the lake with no issues. After landing I shut down and told the guys I was heading for the airport. As soon as I went full power for about 5 seconds the temp swung way up and she blew anti freeze again.. WTF! I shut down, and think I found the problem.

The overflow bottle I have has a line running to the bottom of the bottle (the over flow line goes into the cap of the bottle). The line from the cap to the bottom of the bottle had come off and when the engine warmed up it was pushing the coolant into the bottle, but not drawing it back in when she cooled off. She was sucking air back into the system and as soon as I powered up again, she cavitates and overheats. I have a new bottle at the house that has the line coming into the bottom of the overflow tank and I will be putting that on when I get home.

I got called back to work early so I will only headed home for 3 days for Christmas then back to work for 2 weeks. I am hoping to try out the new bottle this time home, but I may not gett to it. If I do, It will tell me one way or the other if I have correctly diagnosed my issue and I will post it up here to let you know what I find!