YS61ST2 regulator assembly

[paul]

Anyone have an idea what the "factory preset"/"do not adjust" needle on the
regulator assembly is supposed to set to? I bought this engine used and the
sealant had already been removed, now I'm wondering if it has in fact been
"adjusted" to something other than the stock setting and could be the cause
of the inconsistant runs I'm having.

Many thanks

[Rhodesst]

>Anyone have an idea what the "factory preset"/"do not adjust" needle on the
>regulator assembly is supposed to set to? I bought this engine used and the
>sealant had already been removed, now I'm wondering if it has in fact been
>"adjusted" to something other than the stock setting and could be the cause
>of the inconsistant runs I'm having.
>
>Many thanks

Hi Paul,

If the regulater on the YS engine had been messed with, it certainly could be
responsible for the inconsistant runs you're having.

The orginal YS 60 engine (way before the ST versions) didn't have an idle
mixture adjustment. They had a large knob under the crankcase that allowed the
user to adjust the regulated pressure for a proper idle and then the user had
to reset the high speed needle so that everything worked in the air on the new
setting. Only problem was, most folks couldn't adjust that knob properly and
ended up with an engine that didn't run well, if at all. That's why they don't
want us messing with that part of the engine any more.

"If" you're absolutely sure it's been messed with in the first place, you might
try tinkering with it yourself. You might get lucky. OTOH, you might also
have a problem with the regulator that needs more attention than most of us
average modelers are able to give it. In that case, you need to send it in for
adjustment or repair.

One other question that comes to mind. Do you have the original engine
instructions? The pressure line from the back of the crankcase to the one-way
pressure valve has to be a specific length. I'm not remembering it right off
the top of my head, it's around 10 cm, I think. If it's off, the engine will
"not" perform properly. Ask me how I know! ;-) I'd gone through a half dozen
pressure valves before someone mentioned that my pressure line from the engine
didn't look right. It was only a couple of cm's off but it made a "big"
difference in how the engine performed. This may have nothing to do with your
problem but it comes to mind and it's easy to check and fix if it's an issue.
Good luck!

Fly Safe,
Steve R.

[Philip Martin]

Steve's right about the length of the pipe, but also I found that it needs
to be a firm type of tube not the soft silicone. That makes a difference
too!

The other thing to check for is the inside if the regulator. There's a
diaphragm and valve there, I had a load of shit stuck in the counter bore
outlet from the regulator that messed up the running of the engine. It's
fairly straight forward to take apart but can be a bugger to clean!

Phil Martin.



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[Rhodesst]

>Steve's right about the length of the pipe, but also I found that it needs
>to be a firm type of tube not the soft silicone. That makes a difference
>too!
>
Phil, out of curiosity, that type of tubing do you use? I just run my normal
fuel tubing and haven't had any problems with it that I'm aware of. Using a
firmer compound does make sense though.

>The other thing to check for is the inside if the regulator. There's a
>diaphragm and valve there, I had a load of shit stuck in the counter bore
>outlet from the regulator that messed up the running of the engine. It's
>fairly straight forward to take apart but can be a bugger to clean!
>
>Phil Martin.

Something else that popped to mind while reading Phil's response is that I
noticed one of my YS's were leaking a small amoung of fuel around the fuel
regulator. It's the black piece that's bolted to the bottom of the crankcase
opposite the carb. It's held on with four phillips head screws and I was able
to tighten all of mine by just over a quarter turn each. I'd been having an
intermittent burp in the engine from time to time while flying inverted. "Not"
a good place for the engine to start burping! :-o Snugging up those screws
cured the problem. :-)

Fly Safe,
Steve R.

[Guy Nicholas]

Another thing to check is your check valve. Make sure you can blow only one
way through it. Sometimes in a backfire kindof thing the little diaphram in
there can get sucked into the spring that holds it.

Later, Guy

"paul" <crainp@cableone.net> wrote in message
news:v5b995hu1jlb04@corp.supernews.com...
> Anyone have an idea what the "factory preset"/"do not adjust" needle on
the
> regulator assembly is supposed to set to? I bought this engine used and
the
> sealant had already been removed, now I'm wondering if it has in fact been
> "adjusted" to something other than the stock setting and could be the
cause
> of the inconsistant runs I'm having.
>
> Many thanks
>
>

[Rhodesst]

>Another thing to check is your check valve. Make sure you can blow only one
>way through it. Sometimes in a backfire kindof thing the little diaphram in
>there can get sucked into the spring that holds it.
>
>Later, Guy

I had that happen once, before I got the tubing length correct between the
engine and the valve.

It was one of the wildest things I've seen. That little valve was rolled up
like a new paper and neatly slid into the ID of the spring. Even with a
backfire, or whatever it was, I can't imagine "how" it got in that position.

Still puzzled.......
Fly Safe,
Steve R.