Need info re 3W and ST

Need info re 3W and ST

Post by hermes.is.co.z » Sat, 06 Nov 1999 04:00:00



Hi all,

I've two questions:
1) Could anyone tell me the best way to set the idling and fast mixtures on
a 3W 60cc (I think the engine is about 5 years old), it has the carb on the
side, this engine was given to me because the owner never got it to work
properly, it used to run OK on the ground, but as soon as it was airborne,
it seemed to richen up somewhat, and run very spluttery, I have had the carb
overhauled at a local lawnmower / hedgtrimmer shop that deals with these
carbs, but I obviously still need to set the damn thing properly (preferably
on the bench)... any help will be really appreciated.

2) A fellow flyer has just finished  Fiber Classics Mustang, with a ST 60
(twin in-line), he has herd a whole bunch of stories about the crank
pressure being unequal between the two pistons, thus causing the front
piston to lean out and / or the back piston to richen up, is this true and
if so what can be done to remedy the problem...

Any help or pointers in the right direction will be greatly appreciated, I
would however appreciate it if replies could be directed to

Many thanks

Brent

 
 
 

Need info re 3W and ST

Post by Paul Nesbit » Tue, 09 Nov 1999 04:00:00


Quote:

> Hi all,

> I've two questions:
> 1) Could anyone tell me the best way to set the idling and fast mixtures on
> a 3W 60cc (I think the engine is about 5 years old), it has the carb on the
> side, this engine was given to me because the owner never got it to work
> properly, it used to run OK on the ground, but as soon as it was airborne,
> it seemed to richen up somewhat, and run very spluttery, I have had the carb
> overhauled at a local lawnmower / hedgtrimmer shop that deals with these
> carbs, but I obviously still need to set the damn thing properly (preferably
> on the bench)... any help will be really appreciated.

This effect you are seeing if very typical of the side carb 3W engines.
It is one of the reasons that 3W went to the rear induction design.  The
problem seems to be related to varying air pressure on the carburator
diaphram.  The most common fix is to solder a tube on the hole of the
diaphram cover and either point the tube into the carb opening, or route
it back into the fuse where the air pressure is constant.  Trust me, it
does work.

Quote:

> 2) A fellow flyer has just finished  Fiber Classics Mustang, with a ST 60
> (twin in-line), he has herd a whole bunch of stories about the crank
> pressure being unequal between the two pistons, thus causing the front
> piston to lean out and / or the back piston to richen up, is this true and
> if so what can be done to remedy the problem...

I couldn't decide whether to respond to this question or not because my
mama always said "if you can't say something nice.....".  But here goes;
yes, the ST twin has a big problem in equalizing the two cylinders; no,
I have never seen one successfully used; no, there is nothing I know
that can fix this apparent design problem.  What I would recommend is
using a different engine.  A buddy of mine has a Fiber Classics Mustang
with a 4.4 Husky gas motor.  The motor is completely hidden in the cowl
and seems to be a perfect motor (power wise) for this plane.  Tell your
buddy to sell the ST, and call J&A Engineering and get a 4.2 or 4.4 gas
motor.
Quote:

> Any help or pointers in the right direction will be greatly appreciated, I
> would however appreciate it if replies could be directed to

> Many thanks

> Brent


 
 
 

Need info re 3W and ST

Post by Christopher Hind » Wed, 10 Nov 1999 04:00:00


ZDZ 80cc twin inline also fits well in the FiberClassics Spitfire - same
size!

Alternatively the Moki 360 I/L seems to run well (see review at
http://www.justengines.unseen.org/reviews.htm )

Chris

Super Tigres SUCK with a CAPITAL 'S'!


Quote:

> > Hi all,

> > I've two questions:
> > 1) Could anyone tell me the best way to set the idling and fast mixtures
on
> > a 3W 60cc (I think the engine is about 5 years old), it has the carb on
the
> > side, this engine was given to me because the owner never got it to work
> > properly, it used to run OK on the ground, but as soon as it was
airborne,
> > it seemed to richen up somewhat, and run very spluttery, I have had the
carb
> > overhauled at a local lawnmower / hedgtrimmer shop that deals with these
> > carbs, but I obviously still need to set the damn thing properly
(preferably
> > on the bench)... any help will be really appreciated.

> This effect you are seeing if very typical of the side carb 3W engines.
> It is one of the reasons that 3W went to the rear induction design.  The
> problem seems to be related to varying air pressure on the carburator
> diaphram.  The most common fix is to solder a tube on the hole of the
> diaphram cover and either point the tube into the carb opening, or route
> it back into the fuse where the air pressure is constant.  Trust me, it
> does work.

> > 2) A fellow flyer has just finished  Fiber Classics Mustang, with a ST
60
> > (twin in-line), he has herd a whole bunch of stories about the crank
> > pressure being unequal between the two pistons, thus causing the front
> > piston to lean out and / or the back piston to richen up, is this true
and
> > if so what can be done to remedy the problem...

> I couldn't decide whether to respond to this question or not because my
> mama always said "if you can't say something nice.....".  But here goes;
> yes, the ST twin has a big problem in equalizing the two cylinders; no,
> I have never seen one successfully used; no, there is nothing I know
> that can fix this apparent design problem.  What I would recommend is
> using a different engine.  A buddy of mine has a Fiber Classics Mustang
> with a 4.4 Husky gas motor.  The motor is completely hidden in the cowl
> and seems to be a perfect motor (power wise) for this plane.  Tell your
> buddy to sell the ST, and call J&A Engineering and get a 4.2 or 4.4 gas
> motor.

> > Any help or pointers in the right direction will be greatly appreciated,
I
> > would however appreciate it if replies could be directed to

> > Many thanks

> > Brent

 
 
 

Need info re 3W and ST

Post by Jim Whit » Thu, 11 Nov 1999 04:00:00


Quote:

>Super Tigres SUCK with a CAPITAL 'S'!

that's what they are supposed to do.... all of our engines suck air...
and the ST's are only as good as the operator...

Jim White
AMA 2466
WB2WOY
WPMPA/BCF/PFC
SouthShoreSoftware
Treasure Island, FL