mis-fire

mis-fire

Post by sub-standard heli perso » Fri, 10 Sep 2004 06:14:41



With the OS91 C Spec engine in the hover, I've got a mis-fire, is this due
to a lean or rich mixture? the heli is great in a full throttle climb but
when you land and the engine is ticking over the same mis-fire is there.

Cool power 25%

Any help would me appreciated

Regards

 
 
 

mis-fire

Post by BillW5 » Fri, 10 Sep 2004 06:59:37


Well I would set it more rich than lean if it were me (although I am not
into 3D yet). One way to tell is how long you can hover on so many
ounces of fuel. Another thing is the glow plug is very important at and
near idle. If the glow plug gets flaky, you probably will see something
like you are now seeing.

If this isn't helpful, then I would try another batch of fuel. I used to
run Cool Power 30%, but I later switched to WildCat 15% (with 18% pure
synthetic oil). And believe it or not, but the mixture needle ran well
at the same setting between the two. That shouldn't be, as when you
decrease Nitro, it should need to be set leaner.

I don't have anything against Cool Power except I don't see any oil
content labeling and I don't know what I am using. Also I am wondering
if Cool Power 30% is really 30% anyway? Although it could have been a
mismarked batch I got or something. Who knows?

Cheers!

_______________________________________________
Bill (using a HP Pavilion 8655c & Windows 2000)
-- written and edited within Word 2000



Date: Wed, 8 Sep 2004 22:14:41 +0100

With the OS91 C Spec engine in the hover, I've got a mis-fire, is this
due to a lean or rich mixture? the heli is great in a full throttle
climb but when you land and the engine is ticking over the same mis-fire
is there.

Cool power 25%

Any help would me appreciated

Regards

 
 
 

mis-fire

Post by Beav » Fri, 10 Sep 2004 10:31:20




Quote:
> With the OS91 C Spec engine in the hover, I've got a mis-fire, is this due
> to a lean or rich mixture?

If the motor breaks in and out of a pure 2 stroke, you're rich, but a
misfire usually indicates a lack of fuel to burn. This CAN be because it's
too lean, ut it can alse be because the plug's not the right one for the
fuel. Not being a coolpower user 9as you know) I can't say which plug is
best, but *I'D* try an Enya 3 before any other.

Of course, richening the mixture first is the cheapest AND the safest thing
to do, because you'll be hard pressed to damage anything with a rich run.
Not quite so cut and dried if it's a lean run on an already lean motor.

the heli is great in a full throttle climb but

Quote:
> when you land and the engine is ticking over the same mis-fire is there.

Are you using a pumped "C" Spec J?

Quote:

> Cool power 25%

Yeah-(  <G>

--
Beav

Please note my E-mail address is "beavis dot original at ntlworld dot com"
(with the obvious changes)

Beavisland now lives at
www.beavisoriginal.co.uk

 
 
 

mis-fire

Post by sub-standard heli perso » Sat, 11 Sep 2004 03:04:06


Thanks for the response, I'm already running the Enya 3, and yes I forgot to
mention it is the 91SX-H ring C Spec PS

When you say richen up the mixture will this affect the full throttle climb?

 
 
 

mis-fire

Post by Beav » Sat, 11 Sep 2004 04:12:51




Quote:
> Thanks for the response, I'm already running the Enya 3, and yes I forgot
to
> mention it is the 91SX-H ring C Spec PS

> When you say richen up the mixture will this affect the full throttle

climb?

I've got to tell you J, I'm NOT mpressed with the throttling abilities of
the pumped "C" spec. No-one I've spoken to is either, and I believe that
even Curtis has done something "special" to his own pumper to get it to run
right in the mid range. OS are quite particular about telling us not to fart
about with the pump too, so I'm no help at all now:-(

--
Beav

Please note my E-mail address is "beavis dot original at ntlworld dot com"
(with the obvious changes)

Beavisland now lives at
www.beavisoriginal.co.uk

 
 
 

mis-fire

Post by Steve R » Sat, 11 Sep 2004 10:06:38


I used to run OS engines in my helicopters many years ago.  The last one I
had, took a replacement carb (Supertiger 60) and a new piston & liner to
make it idle right, transition properly, and make decent power on the top
end.  :-(

Since then, I've run YS 60's exclusively.  I've yet to have a problem with
them.  I know a bunch of folks who run the C-spec 91.  It's supposed to make
more power than it's YS competition but considering all the comments I seem
to continually hear about them (ie: have to mod this, replace that, etc.) to
make them run anywhere near consistent, I don't see the point.  Maybe Curtis
has the time and recourses to make the modifications necessary to make his
run like it should have in the first place but I don't.

Can anyone explain to me "why" people keep putting up with this kind of cr**
from OS?  They have some of the finest engines on the market, quality wise.
There's no excuse for not being able to pull the C-spec out of the box and
have it run correctly without jumping through hoops in the process.  YS
doesn't seem to have this problem as far as I know.  Am I missing something
here?  :-|

Fly Safe,
Steve R.


Quote:



>> Thanks for the response, I'm already running the Enya 3, and yes I forgot
> to
>> mention it is the 91SX-H ring C Spec PS

>> When you say richen up the mixture will this affect the full throttle
> climb?

> I've got to tell you J, I'm NOT mpressed with the throttling abilities of
> the pumped "C" spec. No-one I've spoken to is either, and I believe that
> even Curtis has done something "special" to his own pumper to get it to
> run
> right in the mid range. OS are quite particular about telling us not to
> fart
> about with the pump too, so I'm no help at all now:-(

> --
> Beav

> Please note my E-mail address is "beavis dot original at ntlworld dot com"
> (with the obvious changes)

> Beavisland now lives at
> www.beavisoriginal.co.uk

 
 
 

mis-fire

Post by Beav » Sat, 11 Sep 2004 20:15:32



Quote:
> I used to run OS engines in my helicopters many years ago.  The last one I
> had, took a replacement carb (Supertiger 60) and a new piston & liner to
> make it idle right, transition properly, and make decent power on the top
> end.  :-(

> Since then, I've run YS 60's exclusively.  I've yet to have a problem with
> them.  I know a bunch of folks who run the C-spec 91.  It's supposed to
make
> more power than it's YS competition but considering all the comments I
seem
> to continually hear about them (ie: have to mod this, replace that, etc.)
to
> make them run anywhere near consistent, I don't see the point.  Maybe
Curtis
> has the time and recourses to make the modifications necessary to make his
> run like it should have in the first place but I don't.

> Can anyone explain to me "why" people keep putting up with this kind of
cr**
> from OS?

I would think because OS have built the most reliable engines over the
years. They took model engines out of the dark ages where a degree in fluid
dynamics was necessary just to get the ***s to run and up to the point
where their engines would run almost right out of the box. Trouble is, they
didn't run far enough:-)))

 They have some of the finest engines on the market, quality wise.

Quote:
> There's no excuse for not being able to pull the C-spec out of the box and
> have it run correctly without jumping through hoops in the process.

I agree, but the early YS motors gave lots of head scratching moments too.
I've not had anything to do with YS for a number of years and little to do
with the larger displacement OS's either, but I'm about to nail a "C" spec
(unpumped) into one of my heli's. time will tell if the unpumped version is
any better than the pumped version.

 YS

Quote:
> doesn't seem to have this problem as far as I know.  Am I missing
something
> here?  :-|

Just YS's development period for their pumped motors. Nothing of any real
use :-))))

--
Beav

Please note my E-mail address is "beavis dot original at ntlworld dot com"
(with the obvious changes)

Beavisland now lives at
www.beavisoriginal.co.uk