582 Starting Problems ...

[rsbiser]

Hi All,
I'm kinda desperate and hope someone out there can help.

Here's my situation ...

I own a Dominator with a Rotax 582. I completed the conversion from a
503 to the 582 about a year ago and it has been a wonderful machine ... until
about 3 weeks ago...

One day I flew my gyro to a neighboring airport. Everything was normal. I
landed, shut it down and just hung out talking to a friend for about 30 minutes.
Went out to fly home and the engine would not start. I could get it to run on
one cylinder but it would not "catch" on the second and smooth out.

We worked on it for a long time ... checking out fuel flow and the carbs. No
problem there. Then we moved to the spark and discovered that we only seemed to
be getting spark on one of the four plugs. I know that doesn't make sense, but
that's what it looked like.

Anyway, I left the machine there and a friend (who knows 100 times more about
Rotax engines than I do) poked around and determined that the CDI units were
bad. I got some other CDI boxes from a friend with a spare 582 block (not new
but in good working order) and they tested much better than my old ones. So now
I have "newer" CDI boxes. With the "new" CDI units, I was able to start it up
and ran it for a while. Shut it down, let it cool and then restarted, with no
problem. So I test flew it in the pattern, landed, shut down and restarted all
with no problems. So I'm thinking my problems are over and I flew it back to my
home airport (about a 7 mile flight over open farm land). It actually performed
better than it ever had. The motor was running very strong and I was very
happy.

So I landed and stopped out on the runway to talk to some RC Flying friends.
When I tried to re-start to taxi back to the hangar, it would not start. Wore
myself out and had to tow it back.

So later that week we took the stator off and discovered that the red wire from
one of the CDI "trigger senders" was frayed and appeared to have been shorting
against the stator. Again, we replaced that sender and made sure that the wire
was neatly tucked under the "fingers" that are designed to keep it safely out of
the way.

After that it started fine ... for "a while". I started it, flew it around the
pattern, shut it down and restarted several times with no problem. Again, I was
convinced that this time we had it nailed and my problems were over!

Then this last Saturday, I had no problem getting it started to fly to a PRA
Club Meeting (only 3.5 miles from my home airport). It ran like a champ on the
flight over and I was feeling pretty good about everything. But, after being
there for a couple of hours, I had a really hard time getting it started. When
I finally did get it started, it ran fine and I flew it home with no issues.

I went back out to the airport on Sunday and "pulled" my butt off (no electric
start) for 30 to 40 minutes trying to start it. I'm back to being able to get
it to run rough on one cylinder, but can't get it to come up on both!

I'm very frustrated. :noidea:

Anyone got any ideas or know anyone else you could point me to who might be able
to help?

Thanks a ton in advance, :hail:

Scott

 

[scottessex]

Scott, look here first, I would guess that it is a fuel problem.

Rotax troubleshooting chart

 

[rsbiser]

Thanks Scott! I'll check it out.

 

[ylf]

Is it safe to assume you have already replaced the plugs?

 

[rsbiser]

Yes. The plugs were only a couple hour old when the problem first occured. And one of the first things we did is replace them with brand new plugs.

Keep asking those questions. I like it.

Thanks,

Scott.

 

[Friendly]

If you use a plug in the exhaust and forget to remove it. The engine will not start. If it does start, it will run, but bog down when you rev it up. You have had the engine ignition down several times, I will go back to the ignition first. I assume you have already traced all of your wires back to the ignition switches to make sure none of them are shorting out.

 

[rsbiser]

Hey Mark,
I'm sure that the exhaust pulg is not a problem. I stuff a big rag in there and cover the air filter with a plastic grocery bag. So I'm 100% confident that neither of those is the problem.

As for the ignition switch wires ... I have visually traced them back. But I think I could do a better job of making sure that they are well insulated all the way from the kill switches to the motor. I'll look closer at that the next time I go to the hangar.

Thanks!

Scott

 

[gyro]

Scott, make sure your not using safety wire anywhere on the plug sockets or the wires. I know I guy that did this to secure the plug sockets from coming off and took him weeks to figure it out. The safety wire will short the plugs out

 

[rsbiser]

Yep.
I'm about 99.9% sure that's not an issue, but I will double check to insure that safety wire on something else is not interfereing with the ignition system.

Thanks,

Scott

 

[ggfirestar]

Is it firing on all 4 plugs or just 1 or 2 on one cylinder?
If you got fire on both cylinder and one not hitting open the enricher if it start's
hitting it in that one carb. I repaired a engine the other day the enricher was bad and someone had plug the pilot jet to get it to idle :usa George

 

[Rehan K.Janjua]

HELLO Scott

Just the same story which happened to me last month.

Landed at 7500ft DA near the Taliban territory and after about an hour
the engine wount start.

To cut the story short it was the battery which didnt crank fast enough.

Try jumping with a larger battery

Good luck.

 

[ylf]

HELLO Scott

... Try jumping with a larger battery

Good luck.

He doesn't have electric start. But maybe you're on to something, maybe Scott is doing something that is weakening his cranking arm.

 

[chuter]

I know my 582 pull start floods real easy; drove me crazy one day. Any possibility it could be flooding?

 

[rsbiser]

Hey Guys,
I'll try to touch on all the last responses with this one post.

It does seem to be running on only one cylinder which could indicate carb problems, but we took both carbs apart and checked the float valves and all the jets for flow. I really don't think it's a carb problem.

Rehan, ylf is right. I have a pull starter and no electric starter. Electric start is certainly on my list. Cause my pull starting arm is getting worn out. I think it's from pulling the starter too many times. I guess it could be something else.

And Chuter, I think you are partly right. I think that I have some ignition problem that renders the motor "hard to start" on the first two or three pulls. After that, it probably does tend to get flooded. Cause I've had my best luck at finally getting it started when I back turn the engine about 20 strokes with the throttle half open and the switches off. Once I start to get tired and frustrated, I probably also prime it too much cause I'm impatient and don't want to continue pulling that #&@$ rope. So with that in mind, electric start might be part of the solution. Kind of like taking asprin to kill the pain without actually fixing the cause of the pain. So I still want to get the underlying ignition issues resolved. If I do that, it should start on the first or second pull and flooding should not be a problem.

Thanks to all of you for your advice and comments,

Scott

 

[scottessex]

Check the compression too, you may have scuffed a piston.

 

[bones]

Chuter, I think you are partly right. I think that I have some ignition problem that renders the motor "hard to start" on the first two or three pulls. After that, it probably does tend to get flooded. Cause I've had my best luck at finally getting it started when I back turn the engine about 20 strokes with the throttle half open and the switches off. Once I start to get tired and frustrated, I probably also prime it too much cause I'm impatient and don't want to continue pulling that #&@$ rope. So with that in mind, electric start might be part of the solution. Kind of like taking asprin to kill the pain without actually fixing the cause of the pain. So I still want to get the underlying ignition issues resolved. If I do that, it should start on the first or second pull and flooding should not be a problem.

Thanks to all of you for your advice and comments,

Scott

Ok now here is an idea for you but only if you know what you are doing, and have a good hold on the machine, hell its only a 582, swing the prop, because for every 1 rev of the prop the motor is doing roughly 2.5 revs so it will be turning over much quicker, and thus might help your starting problem, it is confusing to me though, that it starts good cold, after hot it wont start again, that in itself dont really make sense to me

 

[scottessex]

The spark is almost impossible to see in daylight.
If you have scuffed a piston the engine may start just fine when cold, but after it warms up, and the clearances are looser, the engine will be hard to start.

3 things for internal combustion:

Fuel
Spark
Compression

any one not up to par, the engine will not start.

 

[GyroRon]

Nobody mentioned the obvious....

Scott, did you check the gap on the plugs? Too much gap and the ignition can't make a spark. Gotta be somewhere around 18-19 thousands gap.

Of course you know this already since we spoke on the phone earlier, and I already know the answer is NO... You didn't check the gap! Check it and see if that don't fix your problems.

 

[down under]

A problem I have run into in the past with bikes and the 912, is the wires breaking inside the insulation. The wires will contact at times and not others. The only way to find it is to stretch the wires. If the wire is broken the insulation stretches.

 

[scottessex]

Give Ron a gold star for starting with the obvious and simple, we'll wait and see.