engine woes

[David Harmon]

Georgie....I think this is what you need.

http://www.perrypumps.com/prod01.htm

Dave

-----Original Message-----
From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]
On Behalf Of George Kennie
Sent: Friday, November 15, 2002 8:33 PM
To: discussion at nsrca.org
Subject: engine woes


I purchased an MDS-58 in the spring for my Javelin after purchasing one
at the WRAM show. I selected the MDS because it's almost a 60 in
displacement, but is housed in a small case making it quite light for
the power output. In it's original configuration it had serious
carburetion problems. Subsequent visits to the local hobby shop
disclosed that they were shipping newer releases with a second
generation carburetor touted as the "C2". Being frustrated with the
performance I was receiving I called the distributor and was advised to
return the engine and they would make it right."Wow!, great service,
eh?"  Well 3&1/2 weeks later I received the engine back with the new
"C2" carb installed. The new unit was about 1/3 larger than the
original, requiring additional cutting of the cowl.Early flights were
not perfect which I attributed to the fact that I had left the
adjustments as set by the distributor, which they recommended.
Subsequent flights only went downhill. Yesterday I decided that I was
going to concentrate on getting this engine finally adjusted correctly.
Off to the field I go and get everything set up." First I'm going to get
that low end spot on and get rid of that hesitation". Fuel it up, turn
it over a couple of revs while choking and yup it's drawing fuel. Attach
the igniter and spin it over with the trusty Kavan and
rrr,rrr,rrr,rrr,rrr,rrr,rrr,rrr,rrr ,.....man, is this thing ever going
to fire? Try a different plug! rrr,rrr,rrr,rrr,rrr,rrr,rrr,sput,sput,
vroom(not a big vroom, I'm just off idle). Anyhow, I finally got it
going enough times to finally adjust the low end where it would hold
idle for a full minute at about 2K rpm and cleanly transition to full
power and do it consistantly.Aha, I finally got this buggar clicking!
O.K., now I'm going to fly this bird so I proceed to taxi out to the
center of the runway(which takes a few bursts to 1/2 throttle)and
advance to full and the son-of-a-gun quits dead! Stick it back on the
bench and restart it and it still transitions faultlessly from idle to
full power. Go to 1/2  throttle or just a whisker below and it will run
about 20 seconds and abruptly quit. Play around some more and I finally
get it to run at 1/2 throttle for an extended period of time,but now,
when I go from 1/2 to full it quits about 2 clicks short of full
power.Decided that maybe the pressure is too high causing it to load up
at mid-range so I disconnect the pressure line and try it again. The
only difference is that now the high speed needle is very insensitive,
but all the same conditions still exist.

I can only conclude that the carb design is faulty and would warn
prospective buyers to proceed with caution. I had previously(about a
month and a half ago) installed a carb from a ST-40, which is a perfect
fit, and the engine ran well. I think what I might do is try a Perry,
but I need some help with the Web-site. Can someone help me with that? I
think Varsane sold out to someone named Conelly or something like that.
Thanks for listening to my tale of woe. Georgie

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