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Posa carbs

Peter Harris <peterjfharris@...>
 

Richard,
My Revmaster made 2850rpm static with a Cowley 56x49pitch prop. (but I am not sure if it had the 75HP larger valves).Yours should go faster. Have you confirmed no restriction in fuel flow to the carb? How does it breakdown,/ missfire? (ignition) backfire?(lean),hunting? (too rich) or just level out at 2650?(linkage held up)
Peter

----- Original Message -----
From: richard
To: Q-LIST@...
Sent: Tuesday, June 28, 2005 1:22 AM
Subject: [Q-LIST] Posa carbs


Hello Fellas,

It's me again, I've been trying to still get static rpm in my q-2.
I've check the compression #1 has 160 #2 has 172 #3 has 140 #4 has
170. I have set the valves to .006. I have re checked the timing its
right on. I have checked the prop its a cowley 45p 56 dia. I've had
a local gentleman that has only run rev master's to come to look at
it he has told me that it has not got a big enough carb(34 mm). The
engine is a 21oo d rev master. So I went to sonex today and the guy
there said I had to big of a carb and that on the aero V engines
which are 80 cc bigger there running a 32 mm carb and mine is a 34
mm carb. The engine will run up to 2650 rpm which is 3/4 throttle
and after that she falls on her face.Its like its either getting to
much or not enough fuel. I'm at a loss here and dont want start
speculating and buying parts that I dont need! The other suggestion
from sonex was to limit the throttle at 2650, I dont know if that
would be a good Idea or not, I surely don't want to find out in the
air that it wasn't a good idea! I have another carb coming to try
hopefully it will be here today or tommorow but At this point I'm
thinking its not the carb. I'm in need of some good advice for the
engine. I'm surely not going to take advice from someone who is more
interested in my wallet then what is actually going on. PLEASE HELP!!

THANKS

Rich
N169TB
Stranded in Oshkosh




Quickie Builders Association WEB site
http://www.quickiebuilders.org





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richard <tbatch2000@...>
 

Hello Fellas,

It's me again, I've been trying to still get static rpm in my q-2.
I've check the compression #1 has 160 #2 has 172 #3 has 140 #4 has
170. I have set the valves to .006. I have re checked the timing its
right on. I have checked the prop its a cowley 45p 56 dia. I've had
a local gentleman that has only run rev master's to come to look at
it he has told me that it has not got a big enough carb(34 mm). The
engine is a 21oo d rev master. So I went to sonex today and the guy
there said I had to big of a carb and that on the aero V engines
which are 80 cc bigger there running a 32 mm carb and mine is a 34
mm carb. The engine will run up to 2650 rpm which is 3/4 throttle
and after that she falls on her face.Its like its either getting to
much or not enough fuel. I'm at a loss here and dont want start
speculating and buying parts that I dont need! The other suggestion
from sonex was to limit the throttle at 2650, I dont know if that
would be a good Idea or not, I surely don't want to find out in the
air that it wasn't a good idea! I have another carb coming to try
hopefully it will be here today or tommorow but At this point I'm
thinking its not the carb. I'm in need of some good advice for the
engine. I'm surely not going to take advice from someone who is more
interested in my wallet then what is actually going on. PLEASE HELP!!

THANKS

Rich
N169TB
Stranded in Oshkosh

James Postma <james@...>
 

Rich,

I had some similar problems and had Revmaster dyno my engine. Joe said the
carburetor was too big. Fuel is not the problem it is the air. Instead
of downsizing the carb, I upsized the engine which I wanted to do anyway by
using 94mm pistons and a high performance camshaft. This worked well.

Your #3 compression is much lower than the others. A complete set of
pistons and cylinders is only $200.

Also check for air leaks in the intake system. The joint between the upper
and lower intake manifolds needs to be tight.

James Postma
Q2 Revmaster N145EX
Q2 Revmaster with LS-1
Q200 N8427
Steilacoom, Washington
(253) 584-1182 9:00 to 8:00 PDT
May your header tank be always full and your wings right side up.

----- Original Message -----
From: "richard" <tbatch2000@...>
To: <Q-LIST@...>
Sent: Monday, June 27, 2005 8:22 AM
Subject: [Q-LIST] Posa carbs


Hello Fellas,

It's me again, I've been trying to still get static rpm in my q-2.
I've check the compression #1 has 160 #2 has 172 #3 has 140 #4 has
170. I have set the valves to .006. I have re checked the timing its
right on. I have checked the prop its a cowley 45p 56 dia. I've had
a local gentleman that has only run rev master's to come to look at
it he has told me that it has not got a big enough carb(34 mm). The
engine is a 21oo d rev master. So I went to sonex today and the guy
there said I had to big of a carb and that on the aero V engines
which are 80 cc bigger there running a 32 mm carb and mine is a 34
mm carb. The engine will run up to 2650 rpm which is 3/4 throttle
and after that she falls on her face.Its like its either getting to
much or not enough fuel. I'm at a loss here and dont want start
speculating and buying parts that I dont need! The other suggestion
from sonex was to limit the throttle at 2650, I dont know if that
would be a good Idea or not, I surely don't want to find out in the
air that it wasn't a good idea! I have another carb coming to try
hopefully it will be here today or tommorow but At this point I'm
thinking its not the carb. I'm in need of some good advice for the
engine. I'm surely not going to take advice from someone who is more
interested in my wallet then what is actually going on. PLEASE HELP!!

THANKS

Rich
N169TB
Stranded in Oshkosh




Quickie Builders Association WEB site
http://www.quickiebuilders.org


Yahoo! Groups Links






richard <tbatch2000@...>
 

Peter,
I have confirmed no restiction to the carb, when I get it to 2650 its
3/4 throttle and just falls off as it is getting to much or not
enough gas,no back firing or anything.I have a guy sending me a carb
to try hopefully this will help out.
Thanks
Rich
If you think of anything let me know ... Thanks





--- In Q-LIST@..., "Peter Harris" <peterjfharris@b...>
wrote:
Richard,
My Revmaster made 2850rpm static with a Cowley 56x49pitch prop.
(but I am not sure if it had the 75HP larger valves).Yours should go
faster. Have you confirmed no restriction in fuel flow to the carb?
How does it breakdown,/ missfire? (ignition) backfire?(lean),hunting?
(too rich) or just level out at 2650?(linkage held up)
Peter
----- Original Message -----
From: richard
To: Q-LIST@...
Sent: Tuesday, June 28, 2005 1:22 AM
Subject: [Q-LIST] Posa carbs


Hello Fellas,

It's me again, I've been trying to still get static rpm in my q-
2.
I've check the compression #1 has 160 #2 has 172 #3 has 140 #4
has
170. I have set the valves to .006. I have re checked the timing
its
right on. I have checked the prop its a cowley 45p 56 dia. I've
had
a local gentleman that has only run rev master's to come to look
at
it he has told me that it has not got a big enough carb(34 mm).
The
engine is a 21oo d rev master. So I went to sonex today and the
guy
there said I had to big of a carb and that on the aero V engines
which are 80 cc bigger there running a 32 mm carb and mine is a
34
mm carb. The engine will run up to 2650 rpm which is 3/4 throttle
and after that she falls on her face.Its like its either getting
to
much or not enough fuel. I'm at a loss here and dont want start
speculating and buying parts that I dont need! The other
suggestion
from sonex was to limit the throttle at 2650, I dont know if that
would be a good Idea or not, I surely don't want to find out in
the
air that it wasn't a good idea! I have another carb coming to try
hopefully it will be here today or tommorow but At this point I'm
thinking its not the carb. I'm in need of some good advice for
the
engine. I'm surely not going to take advice from someone who is
more
interested in my wallet then what is actually going on. PLEASE
HELP!!

THANKS

Rich
N169TB
Stranded in Oshkosh




Quickie Builders Association WEB site
http://www.quickiebuilders.org





--------------------------------------------------------------------
----------
Yahoo! Groups Links

a.. To visit your group on the web, go to:
http://groups.yahoo.com/group/Q-LIST/

b.. To unsubscribe from this group, send an email to:
Q-LIST-unsubscribe@...

c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service.



Dave Dugas
 

Richard,
I've been following the Posa carb posts and I'm not sure if this suggestion has been introduced yet. Make sure that the range of travel on your mixture control arm is greater than 90 degrees, just as it shows in the setup instructions. I made a small adjustment to mine and it made a huge difference. Just something to look at....and I hope that I'm not repeating someone elses suggestion. Dave Dugas

richard <tbatch2000@...> wrote:
Peter,
I have confirmed no restiction to the carb, when I get it to 2650 its
3/4 throttle and just falls off as it is getting to much or not
enough gas,no back firing or anything.I have a guy sending me a carb
to try hopefully this will help out.
Thanks
Rich
If you think of anything let me know ... Thanks





--- In Q-LIST@..., "Peter Harris" <peterjfharris@b...>
wrote:
Richard,
My Revmaster made 2850rpm static with a Cowley 56x49pitch prop.
(but I am not sure if it had the 75HP larger valves).Yours should go
faster. Have you confirmed no restriction in fuel flow to the carb?
How does it breakdown,/ missfire? (ignition) backfire?(lean),hunting?
(too rich) or just level out at 2650?(linkage held up)
Peter
----- Original Message -----
From: richard
To: Q-LIST@...
Sent: Tuesday, June 28, 2005 1:22 AM
Subject: [Q-LIST] Posa carbs


Hello Fellas,

It's me again, I've been trying to still get static rpm in my q-
2.
I've check the compression #1 has 160 #2 has 172 #3 has 140 #4
has
170. I have set the valves to .006. I have re checked the timing
its
right on. I have checked the prop its a cowley 45p 56 dia. I've
had
a local gentleman that has only run rev master's to come to look
at
it he has told me that it has not got a big enough carb(34 mm).
The
engine is a 21oo d rev master. So I went to sonex today and the
guy
there said I had to big of a carb and that on the aero V engines
which are 80 cc bigger there running a 32 mm carb and mine is a
34
mm carb. The engine will run up to 2650 rpm which is 3/4 throttle
and after that she falls on her face.Its like its either getting
to
much or not enough fuel. I'm at a loss here and dont want start
speculating and buying parts that I dont need! The other
suggestion
from sonex was to limit the throttle at 2650, I dont know if that
would be a good Idea or not, I surely don't want to find out in
the
air that it wasn't a good idea! I have another carb coming to try
hopefully it will be here today or tommorow but At this point I'm
thinking its not the carb. I'm in need of some good advice for
the
engine. I'm surely not going to take advice from someone who is
more
interested in my wallet then what is actually going on. PLEASE
HELP!!

THANKS

Rich
N169TB
Stranded in Oshkosh




Quickie Builders Association WEB site
http://www.quickiebuilders.org





--------------------------------------------------------------------
----------
Yahoo! Groups Links

a.. To visit your group on the web, go to:
http://groups.yahoo.com/group/Q-LIST/

b.. To unsubscribe from this group, send an email to:
Q-LIST-unsubscribe@...

c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service.






Quickie Builders Association WEB site
http://www.quickiebuilders.org





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Dorothea Keats and Chris Walterson <dkeats@...>
 

Richard----- Regarding your problem. I do not like using an
automotive compression tester. The readings aren't accurate enough.
You need to borrow a differential compression tester. This is what is
used on airplane engines. You put air into the cylinder and see how much
stays. I am sure you are gonna hear air leaking around your valves. If
you haven't got access to one, simply put 80 lbs of air into the
cylinder when the piston is at TDC on compression and you can listen in
the intake or exhaust for valve problems ot the crankcase for ring
trouble.
When you do your runup and get to 2600, pull the nixture and if it speed
up, you're rich and if it slows down, you are lean.
As a last resort, borrow a smaller prop and tune your engine. You will
get your static rpm but when you bolt on your bigger prop, you will be
back to the 2600.
As I said before, I think your engine is week. You need to check the
compression as I suggest and then we can eliminate or confirm the health
of the engine. You need very good compression to achieve the 75 hp.
Have fun--------- Canada Chris

denpau@...
 

Years ago I installed a Mikuni carb on my Onan powered Quickie.
I thought the carb was too big (28mm) because it ran better at less than
3/4 throttle.After working with it foe a while I installed the carb heat box.
It ran well at full throttle.
After a little more experimentation, I found that because the carb was mounted
with the inlet direction at 90 degrees from the prop air flow, just protecting
it from "side ways" blast solved the problem.
I'm pretty sure that Revmasters don't have a sideways mounted carb, but
thought I'd mention it anyway.

Good luck

Dennis

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