MC carb for Webra

Jerry Budd jbudd at QNET.COM
Thu Jun 5 07:25:43 AKDT 2003


Brian,

According to the Piedmont website the baffle is 4" ahead of the aft 
end of the pipe so that puts you at ~27.5" from plug to baffle.  When 
I tried the Greve pipe that Piedmont sells, I found that to be too 
long (way down in power compared to my ES pipe at ~24" plug to 
baffle).

Lee, Jim W., Matt - Are these needle settings close?  I haven't run 
the ProMixII carb in a while.

It sounds to me like the pipe may need to be shortened some, and the 
low end richened up a bit.  You also probably got the motor a bit hot 
when the pump got FOD'd and that's why the internals are a bit dark.

Jerry

>That is from the center of the glow plug to the end of the large portion of
>the pipe, does not include the stinger. Not sure where the first baffle is
>located at.
>----- Original Message -----
>From: "Jerry Budd" <jbudd at QNET.COM>
>To: <discussion at nsrca.org>
>Sent: Thursday, June 05, 2003 10:09 AM
>Subject: Re: MC carb for Webra
>
>
>>    Brian,
>>
>>  The 31.5" pipe length you quote, what is that from?  In other words
>>  what is the distance from the plug to the first baffle in the pipe?
>>
>>  Jerry
>>
>>  >    Jerry, my setup is as follows: Webra 145 red head, greve pipe at
>31.5",
>>  >os typeF plug, cool power 15%, APC 17*12, 10lb. 2oz. Prophecy. Current
>>  >settings on engine are 1 turn on high speed needle, 1 1/16 on low speed
>>  >needle. I am guessing low 8k for top end rpm on the ground slightly rich
>>  >{have not tached the 17*12 but I was getting high 8600 or so with 17*10.
>>  >Engine starts good and idles reliably but transition is not very
>linerier.
>>  >In flight it sounds good with straight and level flight at a little less
>>  >than half throttle, when pulling to a 45 up line it sags momentarily but
>>  >recovers, on tall verticals or loops it will sag toward the top and loose
>>  >roughly 1\2 of it's rpm and that is with me adding throttle through the
>>  >maneuver, engine with not regain good power unless you go to at least 3\4
>or
>>  >better with throttle. I get no smoke trail out of engine until full
>throttle
>>  >and oil out of the pipe is pretty dark but not black, top third of piston
>>  >and ring is black like cyl. temps have been high. Condition is better
>with
>>  >low speed needle set richer but it's easy to flood on start ups and is
>hard
>>  >to keep running when cold {must keep a very fast Idle speed until your in
>>  >the air}. I have found trash in the pump and pump screws came loose
>twice,
>>  >last week I pulled pump apart again and no trash was found but screws
>where
>>  >loose, I cleaned all parts in warm water and dish soap, removed tank and
>>  >cleaned, ran large fuel tubing from clunk to carb. All fuel is filtered
>from
>>  >the jug and I have a filter between tank and pump. That is about all I
>can
>>  >think of, any suggestions would be greatly appreciated.
>>  >----- Original Message -----
>>  >From: "Jerry Budd" <jbudd at QNET.COM>
>>  >To: <discussion at nsrca.org>
>>  >Sent: Thursday, June 05, 2003 12:32 AM
>>  >Subject: Re: MC carb for Webra
>>  >
>>  >
>>  >>  Hi Brian,
>>  >>
>>  >>  What's your setup?  i.e. pipe & length, plug, prop, fuel, airplane
>>  >>  (including weight), rpm's, etc.
>>  >>
>>  >>  The reason I'm asking is I've got quite a bit of experience with the
>>  >>  Webra's (including the MC carb) and I may be able to suggest some
>>  >>  work arounds until the MC is available again via Horizon (I'm
>>  >>  guessing but they probably underestimated the demand for the carb and
>>  >>  got caught short on stock).
>>  >>
>>  >>  Jerry
>>  >>
>>  >>  >Sounds interesting Jim, let me know how it works out. Mine is
>>  >>  >driving me crazy, I have it running ok right now but it is kind of
>>  >>  >off and on type of power. I have been flying her but I know it is
>>  >>  >not right, still managed to get a gallon through it sunday with easy
>>  >>  >starts good reliability but as far as uplines go it is either all or
>>  >>  >nothing, no middle.
>>  >>  >
>>  >>  >----- Original Message -----
>>  >>  >From: <mailto:jivey61 at msn.com>jim ivey
>>  >>  >To: <mailto:discussion at nsrca.org>discussion
>  > >>  >Sent: Wednesday, June 04, 2003 10:30 PM
>>  >>  >Subject: Re: MC carb for Webra
>>  >>  >
>>  >>  >Brian
>>  >>  >I put a cline regulator, a regular back plate with a press. tap, and
>>  >>  >pressurized the tank on my Webra. The ground runs have been more
>>  >>  >stable for throttle position The needles are a lot less sensitive
>>  >>  >and it doesn't seem to be fat in the middle.
>>  >>  >When I find some time to fly I think it will finally run good. I
>>  >>  >must have had a pump problem because too many people are running
>>  >>  >this engine. I did find a piece of foreign material in the pump.
>>  >>  >This was in the pump from day one. I used a YS filter and nuttin'
>>  >>  >gets through a YS filter.
>>  >>  >Will let you know when I fly it, how it does.
>>  >>  >
>>  >>  >Jim Ivey
>>  >>  >
>>  >>  >
>>  >>  >----- Original Message -----
>>  >>  >From: Brian Billings
>>  >>  >Sent: Wednesday, June 04, 2003 2:10 PM
>>  >>  >To: discussion at nsrca.org
>>  >>  >Subject: Re: MC carb for Webra
>>  >>  >
>>  >>  >Thanks Tony, that is what I thought.
>>  >>  >
>>  >>  >----- Original Message -----
>>  >>  >From: <mailto:tony at radiosouthrc.com>Tony Stillman
>>  >>  >To: <mailto:discussion at nsrca.org>discussion at nsrca.org
>>  >>  >Sent: Wednesday, June 04, 2003 9:45 AM
>>  >>  >Subject: Re: MC carb for Webra
>>  >  > >
>>  >>  >Brian:
>>  >>  >
>>  >>  >Horizon is the USA importer for Webra, so if they are out, you
>>  >>  >probably won't find one.  The only other answer is to go direct to
>>  >>  >Webra in Europe.
>>  >>  >
>>  >>  >Tony Stillman
>>  >>  >Radio South
>>  >>  >3702 N. Pace Blvd.
>>  >>  >Pensacola, FL 32505
>>  >>  >1-800-962-7802
>>  >>  ><http://www.radiosouthrc.com/>www.radiosouthrc.com
>>  >>  >
>>  >>  >----- Original Message -----
>>  >>  >From: <mailto:auto7832 at bellsouth.net>Brian Billings
>>  >>  >To: <mailto:discussion at nsrca.org>discussion at nsrca.org
>>  >>  >Sent: Tuesday, June 03, 2003 8:29 PM
>>  >>  >Subject: MC carb for Webra
>>  >>  >
>>  >>  >Does anyone know where I can buy the Webra MC carb, Horizon shows
>>  >>  >them on their website but they don't have any in stock and where
>>  >>  >unable to tell me when they would. Thanks in advance
>>  >>  >
>>  >>  >Brian Billings
>>  >>
>>  >>
>>  >>  --
>>  >>  ___________
>>  >>  Jerry Budd
>>  >>  mailto:jbudd at qnet.com
>>  >>  =====================================
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>>  >>  #
>>  >>
>>  >
>>  >
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>>
>>
>>  --
>>  ___________
>>  Jerry Budd
>>  mailto:jbudd at qnet.com
>>  =====================================
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>>
>
>
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-- 
___________
Jerry Budd
mailto:jbudd at qnet.com
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