4-stroke problem

[george kennie]

Thanks Larry,
I compared my silicon valve to a couple of others that I have in brand new
packages and the one in the engine appears in better shape than either of the
new ones(this is looking through an eye-loop).
Thanks for your interest,
Georgie

jed241 at msn.com wrote:

> George,
>
> I had a similar problem after about 10 flight. I pulled the regulator body
> off and inspected every thing very carefully. The only thing I found was
> flashing on the silcon seal on the end of the plunger. When I applied
> pressure to the spring I could see that the flashing was making contact with
> the regulator body.
>
> I carefully trimmed the flashing off and put it back together. I had to lean
> it a bit more, but haven't touched it in about 20 flights. Very reliable now
> and hasn't failed to start.
>
> I have it in a 5lb 7oz Aresti and it has no problem rocketing the plane
> around.
>
> Hope this helps...
>
> See ya,
>
> Larry
>
> ----- Original Message -----
> From: "george kennie" <geobet at gis.net>
> To: <discussion at nsrca.org>
> Sent: Friday, June 13, 2003 10:25 AM
> Subject: 4-stroke problem
>
> > I'm having a difficult time with a brand new YS-63. Running Powermaster
> > YS-Blend 20/20, 12X6 APC, OS-F. It starts O.K., but when you advance the
> > throttle to full it takes about 20 seconds to slowly build up to max rpm
> > and then if you retard the throttle to anything below 8-9k rpm and leave
> > it there within approx. 5 seconds it will start to "splat, splat, splat"
> > and then abruptly quits, or if you try to advance the throttle it will
> > do the same thing and quit.After it quits, fuel will well up in the carb
> > bowl and overflow like the plunger in the regulator is not seating,
> > however I have inspected the regulator and the plunger silicon valve and
> > everything appears O.K.  I can even blow through the feed aperture in
> > the regulator and no air will go through it until I push on the plunger.
> > The are no burrs or any stickiness impeding the smooth operation of the
> > plunger and yet after a short run of a few seconds it acts like the
> > plunger is sticking in the depressed position.I've tried turning the
> > regulator screw as much as a couple of turns in as well as out and
> > nothing seems to help.
> > Anybody know why the regulator seems to be allowing fuel passage when
> > the engine isn't running? I compared the regulator spring length to a
> > brand new unit and it has the same length. There are no holes in the
> > diaphragm and the silicone valve seat appears smooth and does seat and
> > seal manually.
> > It will Idle, but as I recall that's a completely separate fuel
> > circuit.Is there something in the high speed carburetor circuit that
> > could be malfunctioning in such a way that pressure is getting back to
> > the top side of the plunger and holding it in the open position?
> > What do I do here, guys? Eric? Anyone?
> > Thanks guys,
> > Desperate Georgie
> >
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> >
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