Odd to Me 2-Stroke Running Characteristics

[Dusty 126]

I believe the "hacman" to be easier to install  and very user friendly ,there is plenty online covering this setup,a must have on a cross country 2 stroke it works well.

clip on top of the plastic retainer!  Ouch

[allonsye 85]

I just installed the Hacman last week.  I havent used it yet as its been raining for three weeks.  Joey installed it on his avid a few years back.  He would be the one to ask.

Brian -  I see that the HACman works on vacuum and differential pressure (like an auto compensating fuel injection system) where the Artic Sparrow works by adjusting the needle valve and or slide.  As Dusty points out, I can see the HACman an easier install. 

Edited 10 Nov 2015 by allonsye
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[Knuckledragger 135]

Are you guys installing the Hacman on the 582 gray head? I have one but have not tried to install it yet

[Dusty 126]

Grey/ blue top it doesn't matter which engine but the early carbs don't have the vacuum tapping.

A very simple to install and use systym

[Fly-n-Low 181]

I have been running my mixture control for years and have not had any problems with it. Mike Jacober from Alaska did the conversion for me. Unfortunatly Mike was killed in a trike.  Leni would know more about it than me, he is also using the mixture control  I think.

That's bad. The builder of my Avid had him do the mod too. Might not ever use it because it's only around 75' above here. Nice to have it though I guess.

Edited 10 Nov 2015 by Fly-n-Low

[allonsye 85]

The mixture control would be a nice thing to have beyond any low and slow below 3k asl where most of my flying is presently.  HAC (high altitude compensator) would be nice to have on those rare occasions.  If I begin to take up long cross countrys I'll likely install it.

Getting back on topic; I was stupid and had my carbs too rich.  I must say it's been a good lesson on having the 2-stroke carbs set up correctly.  If it had been too lean however would have quickly destroyed the engine and been an expensive dumb stunts lesson indeed.  There might be a good reason Rotax does not produce their motors w/a mixture control. 

Edited 10 Nov 2015 by allonsye

[tx_swordguy 20]

According to Rotax Rick the HACman will not work on the 670 due to the rave valves. I am assuming it also not work on the 618 but do not know for sure. It is supposed to work well on the 582 and 503 engines. Obviously the higher you fly the more effective it is. 

[Dusty 126]

The hacman should work on the 670,the rave valves start to open around 6500 rpm 

fix the valves in the shut position,(20 thousands of an inch clearance?)

we recently were playing with a 618, manually opening the valves below 6400 rpm bogged the motor.

Rave valves are a great idea for their intended use in snow mobiles where a wide power band is desirable up to rpm we never want t see,power valves are high maintenance , aluminium ones have broken and destroyed  many 618's

[tcj 150]

My 1996 670 Ski Doo has a factory High Altitude Compensator (HAC) system installed on the carbs.  I don't understand the mixture knob on the aircraft aftermarket systems.  The Ski doo HAC is automatic and works great with the RAVE valves.  My clutch is set to hold the engine RPM at 7200 with wide open Throttle.  It pulls like a freight train.

Edited 11 Nov 2015 by tcj

[Fly-n-Low 181]

The mixture control would be a nice thing to have beyond any low and slow below 3k asl where most of my flying is presently.  HAC (high altitude compensator) would be nice to have on those rare occasions.  If I begin to take up long cross countrys I'll likely install it.

Getting back on topic; I was stupid and had my carbs too rich.  I must say it's been a good lesson on having the 2-stroke carbs set up correctly.  If it had been too lean however would have quickly destroyed the engine and been an expensive dumb stunts lesson indeed.  There might be a good reason Rotax does not produce their motors w/a mixture control. 

No not stupid, rich is the place to start. That is what I do with my two strokes when I am starting out with a new build. Glad you have it sorted!

[allonsye 85]

Well on to the next problem. I knew I should of replaced the original throttle cables.  1 hung up and is kinked beyond straightening leaving me with a hung slide and 3300 rpm when i started her this afternoon. 

Where on earth do you get these cable assys. ? ?  I see some on Acft Spruce but not the 24" carb nor the 34" injector.  Looks likes a retrofit with a Bowden.  Maybe it's time to eliminate the bell rank  affair while I'm at it. 

http://www.aircraftspruce.com/catalog/eppages/Engineswithplugsdn.php?recfer=16483

Edited 11 Nov 2015 by allonsye

[C5Engineer 1170]

When my throttle cable went to hell I found a small engine repair shop that specialized in lawnmowers and all things Briggs and Stratton and they custom built me a dual slider cable using my old one as a template. Also while I am thinking of it the reason mine frayed was because at some point after a needle clip adjustment I put the top of the carb on 180 degrees off. Yes they only go one way. The cable had been rubbing. I found it in the Idaho Backcountry while doing another adjustment. It had 3 strands left. Had it snapped the slide would have snapped shut and who knows what the outcome would have been over the gnarliest terrain on the planet after she dropped a cylinder. The Bing 64 is spring loaded wide open...probably a better design.

[Av8r3400 1179]

McFarlane cables are the only ones I'll use in an airplane.  Yes they are expensive.  You definitely get what you pay for. 

http://www.mcfarlaneaviation.com

http://www.mcfarlaneaviation.com/products/?categoryid=258&id=38146066

http://www.mcfarlaneaviation.com/Details.aspx?Article=199

I think you can also get them through ACS & LEAF. 

[allonsye 85]

I like Joey's idea about visiting a lawn mower repair shop. I also see CPS offer individual cable, cable housing, ferrules and what have you to rebuild the OEM with.

[thebriman 69]

I kinda want to get rid of the bell crank too for better sync throughout the whole rpm range....

[allonsye 85]

I kinda want to get rid of the bell crank too for better sync throughout the whole rpm range....

I'd ultimately like to do that as well.  The bellcrank thingy is something else to fail I feel.

Something like this from Aero Controls:

http://www.aerocontrols.net/images/0422944-R1-E004..jpg

 

[Av8r_Sed 82]

I'm not sure you can eliminate the bellcrank. You need the reverser function to work with the Bing 54 slides. 

I ended up making my own custom cables which came out great. The ferrels have to be soldered on after the cables are cut to length and installed in the sheaths. It required making a little solder pot out of a pipe cap which I heated with a torch.  If you're interested, I could dig up some pics and post them up. 

[thebriman 69]

I'm not sure you can eliminate the bellcrank. You need the reverser function to work with the Bing 54 slides. 

I ended up making my own custom cables which came out great. The ferrels have to be soldered on after the cables are cut to length and installed in the sheaths. It required making a little solder pot out of a pipe cap which I heated with a torch.  If you're interested, I could dig up some pics and post them up. 

same way i soldered the ferrules on my choke cables.  great minds......

[allonsye 85]

I'm not sure you can eliminate the bellcrank. You need the reverser function to work with the Bing 54 slides. 

I ended up making my own custom cables which came out great. The ferrels have to be soldered on after the cables are cut to length and installed in the sheaths. It required making a little solder pot out of a pipe cap which I heated with a torch.  If you're interested, I could dig up some pics and post them up. 

 

I'm not sure you can eliminate the bellcrank. You need the reverser function to work with the Bing 54 slides. 

I ended up making my own custom cables which came out great. The ferrels have to be soldered on after the cables are cut to length and installed in the sheaths. It required making a little solder pot out of a pipe cap which I heated with a torch.  If you're interested, I could dig up some pics and post them up. 

I'd be very interested in the the pics.  I was thinking I'd order the necessary bit from CPS but will check if say a lawnmower shop has material locally.  

Hey Brian - given my aircraft is a drive for me and I didn't have the time to take the cables apart, how much/what and quantity do I need?  I think my injector cable is fine for now.  I'm going to leave the major mod for later and focus on replacing the cables just for now. Thanks.

Moderator - this should be migrated or incorporated into a new or existing Throttle Cable thread I must say.

Edited 12 Nov 2015 by allonsye

[allonsye 85]

Does anyone know exactly how or if this set can be incorporated from ACS?

http://www.aircraftspruce.com/catalog/eppages/Engineswithplug3.php

[Av8r_Sed 82]

Here are some pics of the throttle cables I fabricated.

I think I bought the cable parts at ACS.  They've got all the stuff here too: http://www.greenskyadventures.com/throttle_cable/throttlecable.htm  Solder and flux were from the local hardware store. I bought the 45 degree brass tubes from a moped shop for something like $5.  The only shortcoming on them is they won't pass the cable with ferrule installed, so they aren't coming apart.

You just have to be careful set the ferrules so they don't move while dipping in the solder.  I think I slid them up the cable then lifted one wire strand a bit before sliding the ferrules back in place.

-- Sed

[allonsye 85]

Here are some pics of the throttle cables I fabricated.

I think I bought the cable parts at ACS.  They've got all the stuff here too: http://www.greenskyadventures.com/throttle_cable/throttlecable.htm  Solder and flux were from the local hardware store. I bought the 45 degree brass tubes from a moped shop for something like $5.  The only shortcoming on them is they won't pass the cable with ferrule installed, so they aren't coming apart.

You just have to be careful set the ferrules so they don't move while dipping in the solder.  I think I slid them up the cable then lifted one wire strand a bit before sliding the ferrules back in place.

-- Sed

Thanks Sed.  Helpful.

The only bit I'm having trouble sourcing is the larger cable end for the bellcrank side.  No one seems to have those.  Guess I'll have to try to salvage the old ones.

[EDMO 1078]

Here are some pics of the throttle cables I fabricated.

I think I bought the cable parts at ACS.  They've got all the stuff here too: http://www.greenskyadventures.com/throttle_cable/throttlecable.htm  Solder and flux were from the local hardware store. I bought the 45 degree brass tubes from a moped shop for something like $5.  The only shortcoming on them is they won't pass the cable with ferrule installed, so they aren't coming apart.

You just have to be careful set the ferrules so they don't move while dipping in the solder.  I think I slid them up the cable then lifted one wire strand a bit before sliding the ferrules back in place.

-- Sed

Thanks Sed.  Helpful.

The only bit I'm having trouble sourcing is the larger cable end for the bellcrank side.  No one seems to have those.  Guess I'll have to try to salvage the old ones.

Simple to make these out of the right size coldrolled steel (1020-1040) rod, just drill the crosshole and solder them on.

Or, you could even use a grade 2 or 5 bolt shank cut to length.

EDMO

Edited 13 Nov 2015 by EDMO

[allonsye 85]

Here are some pics of the throttle cables I fabricated.

I think I bought the cable parts at ACS.  They've got all the stuff here too: http://www.greenskyadventures.com/throttle_cable/throttlecable.htm  Solder and flux were from the local hardware store. I bought the 45 degree brass tubes from a moped shop for something like $5.  The only shortcoming on them is they won't pass the cable with ferrule installed, so they aren't coming apart.

You just have to be careful set the ferrules so they don't move while dipping in the solder.  I think I slid them up the cable then lifted one wire strand a bit before sliding the ferrules back in place.

-- Sed

The only bit I'm having trouble sourcing is the larger cable end for the bellcrank side.  No one seems to have those.  Guess I'll have to try to salvage the old ones.

Simple to make these out of the right size coldrolled steel (1020-1040) rod, just drill the crosshole and solder them on.

Or, you could even use a grade 2 or 5 bolt shank cut to length.

EDMO

Thanks ED - most excellent tip.