Webra 145 pump pressure ?

[Grow Pattern]

 Paul,
           I have been thinking about your Webra problem. Your rpm seems too 
low for that prop.  I was wondering which MAC pipe you are running? I have 
found the 145 to be a bit fussy in the mid range if the pipe volume is not 
big enough. It also needs a good taper at the front of the pipe to get a 
good transition. Your pipe could be partially blocked?

The OS 1.40 pipe, and/or ES CF clone pipe, has proven to be a good pipe for 
this motor.

 I believe that you are right about the pump but it is also related to tank 
position. The pump does not deliver quite enough fuel in the mid range which 
might be why it is getting hot on sustained 1/2 throttle. You can help your 
pump perform by moving the tank forward a bit.  If the back of the tank is 
on the CG it does not seem to mess much with the flight CG as it drains 
fuel.

Quite a few folks have richened up the pump with good results. I would try 
the above external changes first before you start messing with it.

A big "no!" to Castor content. Just fit the new BOCA stainless steel 
bearing. I would also soak the liner, ring and piston parts in an 
Acetone/Lacquer-thinner mix to remove any shellac build up.

Regards,

Eric.



    My Webra has a good top and bottom end. Only about a gallon and a half 
through it so far.
  The top end is nice and smokey, idle is solid, but the mid range is very 
little smoke.
  It is on a Prophecy running a 16.5 x 12 at 7300 rpm with the Macs pipe  at 
27  inches.

  Most of my flight is at roughly 1/2 throttle. When I land the oil  residue 
on the coupler and
 fuselage is medium brown - fuel is a mix of 20 % synthetic and 5 % 
synthetic.  Main needle is open 1.5 turns.
  am wondering if I should increase the pump pressure to richen up  the 
midrange.
 Or am I just being too fussy ?
 Thanks,
 Paul Horan
 > =================================================
> To access the email archives for this list, go to
> http://lists.f3a.us/pipermail/nsrca-discussion/
> To be removed from this list, go to http://www.nsrca.org/discussionA.htm
> and follow the instructions.
>
> List members email returned for mailbox full will be removed from the 
> list.
> 

=================================================
To access the email archives for this list, go to
http://lists.f3a.us/pipermail/nsrca-discussion/
To be removed from this list, go to http://www.nsrca.org/discussionA.htm
and follow the instructions.

List members email returned for mailbox full will be removed from the list.