ROTAX 582 CARBURATOR PROBLEMS.

[BOOMARANG]

I just bought an Aquilla with a Rotax 582. The motor has 39.5 hours on since it has been zeroed. It was not flown for 8 months and only started once a month during this period. The engine starts and idle perfect. It revs freely , but when you come of the accelerator and then hit the gas like you would in an emergency, the motor "smothers" and dies. however if you accelerate gradually the revs pick up like it should.

On opening the carbs I found a white creamy substance in the one carburator. I have cleaned out both carbs, fitted new fuel lines, flushed the fuel tank,fitted a new fuel filter, fitted new plugs and it still does it.

Anybody got any advice please?

[nickjaxe]

When you say you have cleaned the carbs.........have you taken all the jets out to clean them......is the fuel level correct in the float bowl when it bogs down.

Nick.

[BOOMARANG]

Hi Nick

I have stripped the carbs completely and made sure the jets are open. Washed everything in clean petrol and dried it with compressed air before reassembling it again. Must admit i did not check the float levels after it bogs down. will go and do this morning.

When I did take the carbs of to clean I noticed that ,in the front carb, there were fuel lying in the port that goes from the carb to the engine.

Thanks for the help so far.

Cor

[Alkemac]

"...When I did take the carbs of to clean I noticed that ,in the front carb, there were fuel lying in the port that goes from the carb to the engine..."

IMHO, I would suggest that there is too much fuel, which might be because of a leak in one of the floats, and may be sinking, rather than floating, which should block the inlet.

[nickjaxe]

Yes next time you get it to bog stop it right away and make sure both bowls are to the correct level, did you check the jet numbers all match and are the ones fitted as std,

What about the prop....its not to course is it.....before you fitted new plugs did you notice the plugs colours,

Just in case you have not seen them....there is a wealth of carb info in these articles you can also check your jet sizes from that website.

http://www.800-airwolf.com/articles.htm

Nick.

[BOOMARANG]

Thanks for all the advice.

All the jets were in spec etc and the plugs that I replaced were the right colour. Must say the theory on the sinking float sounds like the one to me. I saw a nick on the one float and (believe it or not) sucked on it to see if it leaks. but maybe that could be it. Will check tomorrow.

The float levels are perfect even after it bogs down.

This is really baffeling. I am begining to wonder if it could not be a ignition problem.

Will search that website and continue my quest tomorrow while the others fly!

[nickjaxe]

I dont think the floats are hollow but I maybe wrong, if you have a good read of the CPS articles I'm sure the answer will be there,

I presume its only recently started doing this......was it ok in the past.

Nick.

[nickjaxe]

Also have read here.

http://www.ultralightnews.ca/bing/bingcarbtuning.html



They seem to think weak idle mixture.

Nick.

[Ranger]

Check the electrical system and spark strength. A good clue as to whether it is the electrical system is to accel quickly and just before it smothers and dies come off the throttle. The motor will then go back to idle. Then immediately accelerate gradually and the motor should rev up. It happens when the spark is very weak and the sudden rush of fuel wants to kill the spark same as if choke is open. If nothing has been changed in the carbs and everything is as it should be don't tamper. Check all the electrical connectors and fixing screws. Also sometimes things look fine but a wire could be broken or holding on via one thread inside the loom. Just a bit of what i've experienced in the past. Hope you get it sorted.

[BOOMARANG]

Thanks for all the advice.

What I also noticed is that it does not want to start without the choke on. Even when warm, she just swings and only after a while start to show signs of starting. With the choke out however, she starts immediatly. At first i tough she was getting to much fuel, but now it seems that she is starving of fuel.

Ranger, the enigine does exactly what you discribe. I also started to think that the fault must be electrical, as the only thing I have not checked or changed so far is the fuel.

Ill see what tommorrow holds as this is getting very frustrating.

[nickjaxe]

Have you checked the slow running or idle mixtures and jet sizes, or trying the revs prob that you have with the choke/enricher part on to see if the prob improves.

Nick.

[Boet]

If you found "white stuff" inside the carbs, there might be some in the petrol pump as well. Have you checked? It sounds as if your engine is running out of gas.....

[Boet]

So what exactly was wrong then? Just curious to know. We can all learn from it.

[BOOMARANG]

Sorry for taking so long to respond.

And the problem was............. wait for it........... THE IDLING WAS TO LOW!!!!

After 11 hours of searching, stripping, cleaning, replacing etc etc I finaly got desperate. I took the two carbs of a friends 582, fitted it to mine and it worked perfect. Then I realised that the engine was idling higher then with my carbs on. Set the idling on his carbs to 2000 rpm and it bogged down. Set it back to 2200 rpm and it worked perfect.

Put my carbs back on, set the idling to 2200 rpm and the problem was solved. Now I believe that the 582 should idle at 2000 rpm, but all I know is that the extra 200 rpm solved the problem. After 11 hours and R1500 worth of plugs, filters etc I was quite happy to accept the outcome.

In the process I also found out that a carb kit cost over R5000 .............rediculious me thinks.

Thanks for all the advice and help, I really appreciate it.

Cor

[Oupa-G]

Was the fuel fresh?

Oupa-G