Duratrax Maximum BX Problems

Duratrax Maximum BX Problems

Post by ffejef.. » Fri, 02 Jun 2006 11:24:19



I have an older Duratrax maximum BX, I took it apart several years ago
and decided to put it back together just the other day.  I was able to
get it started and it ran through a half tank of gas like normal, after
adjusting the carb.  However I went to start it back up and I can see
that the carb is only open a small amount, but when I start it, it will
race at extremely fast RPM's then shut down.  I have tried adjusting
all the needles, but have not solved the problem.  It its a Torq .12
engine, and I'm open to any suggestions.  And if anybody knowns how far
out all the idle screws are supposed to be, that would be helpful, but
I've tried them in all positions.
 
 
 

Duratrax Maximum BX Problems

Post by \ » Fri, 02 Jun 2006 12:19:52



Quote:
>I have an older Duratrax maximum BX, I took it apart several years ago
> and decided to put it back together just the other day.  I was able to
> get it started and it ran through a half tank of gas like normal, after
> adjusting the carb.  However I went to start it back up and I can see
> that the carb is only open a small amount, but when I start it, it will
> race at extremely fast RPM's then shut down.  I have tried adjusting
> all the needles, but have not solved the problem.  It its a Torq .12
> engine, and I'm open to any suggestions.  And if anybody knowns how far
> out all the idle screws are supposed to be, that would be helpful, but
> I've tried them in all positions.

It's starving for fuel or getting too much air.  It starts in a lean
situation, resulting in high RPM and then dies due to lack of fuel or too
much air in the mixture.  You either have an exhaust pressure leak (header,
coupler and/or pressure line), a blockage or leak somewhere in the fuel
tank/lines/carb or maybe a head gasket leak and/or backplate leak..

If I were you, I would:

1.  Remove carb and blow it out using compressed air and denatured ***
as a solvent.  If it sat for awhile it might have gummed up.
2.  Replace all fuel and exhaust line.
3.  Deep six the gas tank in a bowl of water and check for leaks by plugging
the feed line and blowing into the pressure line.
4.  Check all head gasket screws for tightness.
5.  Check header screws and header gasket for damage.
6.  Check exhaust coupler (between manifold and pipe) for leaks.
7.  Check engine backplate for leaks.

HTH,

Doc

 
 
 

Duratrax Maximum BX Problems

Post by M78Ultr » Sat, 03 Jun 2006 03:51:03


sounds like the low speed needle is in too far (lean)...
this can burn up the motor bearings pretty easy...


Quote:
> I have an older Duratrax maximum BX, I took it apart several years ago
> and decided to put it back together just the other day.  I was able to
> get it started and it ran through a half tank of gas like normal, after
> adjusting the carb.  However I went to start it back up and I can see
> that the carb is only open a small amount, but when I start it, it will
> race at extremely fast RPM's then shut down.  I have tried adjusting
> all the needles, but have not solved the problem.  It its a Torq .12
> engine, and I'm open to any suggestions.  And if anybody knowns how far
> out all the idle screws are supposed to be, that would be helpful, but
> I've tried them in all positions.

 
 
 

Duratrax Maximum BX Problems

Post by M78Ultr » Sat, 03 Jun 2006 03:55:24


here's the manual for the maximum bx......
http://www.duratrax.com/pdf/dtxc0065-manual.pdf


Quote:
> sounds like the low speed needle is in too far (lean)...
> this can burn up the motor bearings pretty easy...



> > I have an older Duratrax maximum BX, I took it apart several years ago
> > and decided to put it back together just the other day.  I was able to
> > get it started and it ran through a half tank of gas like normal, after
> > adjusting the carb.  However I went to start it back up and I can see
> > that the carb is only open a small amount, but when I start it, it will
> > race at extremely fast RPM's then shut down.  I have tried adjusting
> > all the needles, but have not solved the problem.  It its a Torq .12
> > engine, and I'm open to any suggestions.  And if anybody knowns how far
> > out all the idle screws are supposed to be, that would be helpful, but
> > I've tried them in all positions.