Ltd. Superjet won't make RPM's

Thanks for the ideas momar,

I checked the reeds anyway, they're ok. It's not a water injection
problem, I unplugged it and did a run just to check.

I just finished testing the CDI to the Yamaha service manual, all of
the resistances appear to be in tolerance, except for the
Black-BrownWhite combo (charger coil), which measures at about 9 ohms,
where the manual tolerance is 2-6. However, it's a cheap analog
tester that I'm using, so there's likely an error in the reading.

Where I did run into a problem is with the pulser coil
(RedWhite-Black). I am getting infinite resistance, where the manual
lists 12.6 - 15.4 ohms. To make sure I'm doing this right, I touch
the black lead to ground, the red lead to the RedWhite wire at the
electrical box, which leads to the flywheel.

Before I go out buying parts, is there anything else I should check,
or do you think this is the problem?

Chris







"momar" <momarski.TakeThisOut@yahoo.com> wrote in message news:<vfabnl6m8upi95.TakeThisOut@corp.supernews.com>...
 > usually the culprit is reeds , since you replaced the reeds the next culprit
 > is the cdi, and if you have water injection, water in a dry pipe can lower
 > the rpm's
 > "Chris B" <cberkis.TakeThisOut@cadorath.com> wrote in message
 > news:36577736.0306211819.7e3edb83@posting.google.com...
  > > My Ltd. superjet was feeling slow and sluggish, so I went and bought a
  > > Tiny Tach to help with some tuning. Turns out I was right. The
  > > highest RPM I could reach is 6130.
  > >
  > > This spring, I replaced all seals and gaskets, new pistons and rings
  > > (bored to 710 cc, 0.5 mm oversize), and new reeds.
  > >
  > > I have the following setup: Factory dry pipe, Riva head (pump gas),
  > > stock carbs, Solas X prop. The exhaust coupler is also new, along
  > > with the o-ring that seals the pipe to the manifold.
  > >
  > > Right now, I'm at a loss as to where to start looking for problems. I
  > > reinstalled the head and pipe today, everything looks fine. Any ideas
  > > or help would be appreciated.
  > >
  > > Chris<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Ltd. Superjet won't make RPM's 

Did you pressure test your pipe?

Nate
"Chris B" <cberkis DeleteThis @cadorath.com> wrote in message
news:36577736.0306221251.127006d6@posting.google.com...
 > Thanks for the ideas momar,
 >
 > I checked the reeds anyway, they're ok. It's not a water injection
 > problem, I unplugged it and did a run just to check.
 >
 > I just finished testing the CDI to the Yamaha service manual, all of
 > the resistances appear to be in tolerance, except for the
 > Black-BrownWhite combo (charger coil), which measures at about 9 ohms,
 > where the manual tolerance is 2-6. However, it's a cheap analog
 > tester that I'm using, so there's likely an error in the reading.
 >
 > Where I did run into a problem is with the pulser coil
 > (RedWhite-Black). I am getting infinite resistance, where the manual
 > lists 12.6 - 15.4 ohms. To make sure I'm doing this right, I touch
 > the black lead to ground, the red lead to the RedWhite wire at the
 > electrical box, which leads to the flywheel.
 >
 > Before I go out buying parts, is there anything else I should check,
 > or do you think this is the problem?
 >
 > Chris
 >
 >
 >
 >
 >
 >
 >
 > "momar" <momarski DeleteThis @yahoo.com> wrote in message
news:<vfabnl6m8upi95 DeleteThis @corp.supernews.com>...
  > > usually the culprit is reeds , since you replaced the reeds the next
culprit
  > > is the cdi, and if you have water injection, water in a dry pipe can
lower
  > > the rpm's
  > > "Chris B" <cberkis DeleteThis @cadorath.com> wrote in message
  > > news:36577736.0306211819.7e3edb83@posting.google.com...
   > > > My Ltd. superjet was feeling slow and sluggish, so I went and bought a
   > > > Tiny Tach to help with some tuning. Turns out I was right. The
   > > > highest RPM I could reach is 6130.
   > > >
   > > > This spring, I replaced all seals and gaskets, new pistons and rings
   > > > (bored to 710 cc, 0.5 mm oversize), and new reeds.
   > > >
   > > > I have the following setup: Factory dry pipe, Riva head (pump gas),
   > > > stock carbs, Solas X prop. The exhaust coupler is also new, along
   > > > with the o-ring that seals the pipe to the manifold.
   > > >
   > > > Right now, I'm at a loss as to where to start looking for problems. I
   > > > reinstalled the head and pipe today, everything looks fine. Any ideas
   > > > or help would be appreciated.
   > > >
   > > > Chris<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Ltd. Superjet won't make RPM's 

I haven't checked the pipe, although now that you mention it, I am
hearing a 'resonance' sound. The last time that happened, turns out
the forward mount flange was cracked.

Back to the pressure test. I assume we're checking for an exhaust
leak into the water jacket. Would a leak test do the trick? I'm
thinking filling the exhaust chamber with water that has a dye in it,
and seeing what comes out the hoses. How would you cap off the ends
for a pressure test, and to what air pressure?

Chris


"Paco \"The Flyin' Finn\"" <nboris.TakeThisOut@gorge.net> wrote in message news:<vfcdvarl0iag21.TakeThisOut@corp.supernews.com>...
 > Did you pressure test your pipe?
 >
 > Nate
 > "Chris B" <cberkis.TakeThisOut@cadorath.com> wrote in message
 > news:36577736.0306221251.127006d6@posting.google.com...
  > > Thanks for the ideas momar,
  > >
  > > I checked the reeds anyway, they're ok. It's not a water injection
  > > problem, I unplugged it and did a run just to check.
  > >
  > > I just finished testing the CDI to the Yamaha service manual, all of
  > > the resistances appear to be in tolerance, except for the
  > > Black-BrownWhite combo (charger coil), which measures at about 9 ohms,
  > > where the manual tolerance is 2-6. However, it's a cheap analog
  > > tester that I'm using, so there's likely an error in the reading.
  > >
  > > Where I did run into a problem is with the pulser coil
  > > (RedWhite-Black). I am getting infinite resistance, where the manual
  > > lists 12.6 - 15.4 ohms. To make sure I'm doing this right, I touch
  > > the black lead to ground, the red lead to the RedWhite wire at the
  > > electrical box, which leads to the flywheel.
  > >
  > > Before I go out buying parts, is there anything else I should check,
  > > or do you think this is the problem?
  > >
  > > Chris
  > >
  > >
  > >
  > >
  > >
  > >
  > >
  > > "momar" <momarski.TakeThisOut@yahoo.com> wrote in message
 > news:<vfabnl6m8upi95.TakeThisOut@corp.supernews.com>...
   > > > usually the culprit is reeds , since you replaced the reeds the next
 > culprit
   > > > is the cdi, and if you have water injection, water in a dry pipe can
 > lower
   > > > the rpm's
   > > > "Chris B" <cberkis.TakeThisOut@cadorath.com> wrote in message
   > > > news:36577736.0306211819.7e3edb83@posting.google.com...
   > > > > My Ltd. superjet was feeling slow and sluggish, so I went and bought a
   > > > > Tiny Tach to help with some tuning. Turns out I was right. The
   > > > > highest RPM I could reach is 6130.
   > > > >
   > > > > This spring, I replaced all seals and gaskets, new pistons and rings
   > > > > (bored to 710 cc, 0.5 mm oversize), and new reeds.
   > > > >
   > > > > I have the following setup: Factory dry pipe, Riva head (pump gas),
   > > > > stock carbs, Solas X prop. The exhaust coupler is also new, along
   > > > > with the o-ring that seals the pipe to the manifold.
   > > > >
   > > > > Right now, I'm at a loss as to where to start looking for problems. I
   > > > > reinstalled the head and pipe today, everything looks fine. Any ideas
   > > > > or help would be appreciated.
   > > > >
   > > > > Chris<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Ltd. Superjet won't make RPM's 

no your checking for water from the water jacket leaking into the exhaust
chamber which would definatlley lower your r's seal all the holes and pump
twenty pounds in their and see if it goes down
"Chris B" <cberkis.DeleteThis@cadorath.com> wrote in message
news:36577736.0306230702.2679e0b0@posting.google.com...
 > I haven't checked the pipe, although now that you mention it, I am
 > hearing a 'resonance' sound. The last time that happened, turns out
 > the forward mount flange was cracked.
 >
 > Back to the pressure test. I assume we're checking for an exhaust
 > leak into the water jacket. Would a leak test do the trick? I'm
 > thinking filling the exhaust chamber with water that has a dye in it,
 > and seeing what comes out the hoses. How would you cap off the ends
 > for a pressure test, and to what air pressure?
 >
 > Chris
 >
 >
 > "Paco \"The Flyin' Finn\"" <nboris.DeleteThis@gorge.net> wrote in message
news:<vfcdvarl0iag21.DeleteThis@corp.supernews.com>...
  > > Did you pressure test your pipe?
  > >
  > > Nate
  > > "Chris B" <cberkis.DeleteThis@cadorath.com> wrote in message
  > > news:36577736.0306221251.127006d6@posting.google.com...
   > > > Thanks for the ideas momar,
   > > >
   > > > I checked the reeds anyway, they're ok. It's not a water injection
   > > > problem, I unplugged it and did a run just to check.
   > > >
   > > > I just finished testing the CDI to the Yamaha service manual, all of
   > > > the resistances appear to be in tolerance, except for the
   > > > Black-BrownWhite combo (charger coil), which measures at about 9 ohms,
   > > > where the manual tolerance is 2-6. However, it's a cheap analog
   > > > tester that I'm using, so there's likely an error in the reading.
   > > >
   > > > Where I did run into a problem is with the pulser coil
   > > > (RedWhite-Black). I am getting infinite resistance, where the manual
   > > > lists 12.6 - 15.4 ohms. To make sure I'm doing this right, I touch
   > > > the black lead to ground, the red lead to the RedWhite wire at the
   > > > electrical box, which leads to the flywheel.
   > > >
   > > > Before I go out buying parts, is there anything else I should check,
   > > > or do you think this is the problem?
   > > >
   > > > Chris
   > > >
   > > >
   > > >
   > > >
   > > >
   > > >
   > > >
   > > > "momar" <momarski.DeleteThis@yahoo.com> wrote in message
  > > news:<vfabnl6m8upi95.DeleteThis@corp.supernews.com>...
   > > > > usually the culprit is reeds , since you replaced the reeds the next
  > > culprit
   > > > > is the cdi, and if you have water injection, water in a dry pipe can
  > > lower
   > > > > the rpm's
   > > > > "Chris B" <cberkis.DeleteThis@cadorath.com> wrote in message
   > > > > news:36577736.0306211819.7e3edb83@posting.google.com...
   > > > > > My Ltd. superjet was feeling slow and sluggish, so I went and
bought a
   > > > > > Tiny Tach to help with some tuning. Turns out I was right. The
   > > > > > highest RPM I could reach is 6130.
   > > > > >
   > > > > > This spring, I replaced all seals and gaskets, new pistons and
rings
   > > > > > (bored to 710 cc, 0.5 mm oversize), and new reeds.
   > > > > >
   > > > > > I have the following setup: Factory dry pipe, Riva head (pump
gas),
   > > > > > stock carbs, Solas X prop. The exhaust coupler is also new, along
   > > > > > with the o-ring that seals the pipe to the manifold.
   > > > > >
   > > > > > Right now, I'm at a loss as to where to start looking for
problems. I
   > > > > > reinstalled the head and pipe today, everything looks fine. Any
ideas
   > > > > > or help would be appreciated.
   > > > > >
   > > > > > Chris<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Ltd. Superjet won't make RPM's