Is anyone that is using a CR 80 motor using the stock keihin PE 28mm (non power jet) carb on their RS 80?
Or... Is everyone running a powerjet carb? If so, which one?
Thanks,
Chris
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Is anyone that is using a CR 80 motor using the stock keihin PE 28mm (non power jet) carb on their RS 80?
Or... Is everyone running a powerjet carb? If so, which one?
Thanks,
Chris
Is anyone that is using a CR 80 motor using the stock keihin PE 28mm (non power jet) carb on their RS 80?
Or... Is everyone running a powerjet carb? If so, which one?
Thanks,
Chris
In the spirit of keeping close competition, I have found that the Keihin PWK 28mm D slide is a very effective carb. It has great response throughout the band and is easy to jet. There is also lots of info available out there for it. I hope I was some help, Anthony.
In the spirit of keeping close competition, I have found that the Keihin PWK 28mm D slide is a very effective carb. It has great response throughout the band and is easy to jet. There is also lots of info available out there for it. I hope I was some help, Anthony.
I was told the "D" slide was the way to go, but I didn't notice a big gain in performance.
I seem to have lost my carb, so I'm running the 'stock' 28m round slide for now.
one thing you may want to do is ensure the pilot jet is richer than you think. I have seen a couple of motors sieze when the rider chops the thottle at the end of a long straight.
I was told the "D" slide was the way to go, but I didn't notice a big gain in performance.
I seem to have lost my carb, so I'm running the 'stock' 28m round slide for now.
one thing you may want to do is ensure the pilot jet is richer than you think. I have seen a couple of motors sieze when the rider chops the thottle at the end of a long straight.
Thanks guys, I was mostly looking to see if the Power Jet was needed. From what I gather, non power jet carbs need to be fat enough just off the pilot that they don't lean out too much when you feather the throttle back. The power jet takes care of that so you can run it crisp on the pilot, yet squirt the richening shot in there when it needs it in that transition off the pilot and on to the needle.
Am I on the right track?!?!
Thanks again.
C
Thanks guys, I was mostly looking to see if the Power Jet was needed. From what I gather, non power jet carbs need to be fat enough just off the pilot that they don't lean out too much when you feather the throttle back. The power jet takes care of that so you can run it crisp on the pilot, yet squirt the richening shot in there when it needs it in that transition off the pilot and on to the needle.
Am I on the right track?!?!
Thanks again.
C
Actually............
The power jet circuits are metered as
part of the main circuit and are on
untill a predetermined high RPM then shut
off. The TM, PJ type carbs tend to run
rich at high RPM so they use the
power jet to balance this out.
Older TZ's and pre '02 RS's it was a
fixed setting at about 12K RPM.
Newer RS's it is tuner adjustable with
different plugs in the wire harness from
11 - 13K RPM.
The power jet has absolutely no effect on
the fuel mixture till about 1/2 throttle
regaurdless of rpm. It is a
siphon that works off air pressure differentials
and there isn't enough air flow at
lower throttle settings for it to function.
You may have it confused with an accelerator
pump.
[img]/ubbthreads/images/%%GRAEMLIN_URL%%/smile.gif[/img]
Actually............
The power jet circuits are metered as
part of the main circuit and are on
untill a predetermined high RPM then shut
off. The TM, PJ type carbs tend to run
rich at high RPM so they use the
power jet to balance this out.
Older TZ's and pre '02 RS's it was a
fixed setting at about 12K RPM.
Newer RS's it is tuner adjustable with
different plugs in the wire harness from
11 - 13K RPM.
The power jet has absolutely no effect on
the fuel mixture till about 1/2 throttle
regaurdless of rpm. It is a
siphon that works off air pressure differentials
and there isn't enough air flow at
lower throttle settings for it to function.
You may have it confused with an accelerator
pump.
[img]/ubbthreads/images/%%GRAEMLIN_URL%%/smile.gif[/img]
FWIW I've never ran a power jet on any of my 2 strokes...
80cc or RZ350
FWIW I've never ran a power jet on any of my 2 strokes...
80cc or RZ350
See now, this is why I ask you guys this stuff.
I WAS mistaking this for the accelerator pump. (four stroke mx guy ya know)
Thanks again.
Chris
See now, this is why I ask you guys this stuff.
I WAS mistaking this for the accelerator pump. (four stroke mx guy ya know)
Thanks again.
Chris
Chris,
I am running a stock cr 80 carb on a 2001 cr 80 motor. The bike performs really well, and several people have said the same thing. I like to think I just get a better drive out of the corner but people always say I pull them on the straight. [img]/ubbthreads/images/%%GRAEMLIN_URL%%/smile.gif[/img] The motor is completely stock except for a power reed.
Later, Eric
Chris,
I am running a stock cr 80 carb on a 2001 cr 80 motor. The bike performs really well, and several people have said the same thing. I like to think I just get a better drive out of the corner but people always say I pull them on the straight. [img]/ubbthreads/images/%%GRAEMLIN_URL%%/smile.gif[/img] The motor is completely stock except for a power reed.
Later, Eric
While we are on the subject.
I am going to run an 01 CR-80 motor with a PWK 28
Problem being that I found a good deal on the carb and it was not set up for this motor.
I would be very appreciative if somebody fill me in on what slide, pilot and main seems to work well.
Thanks,
Troy
While we are on the subject.
I am going to run an 01 CR-80 motor with a PWK 28
Problem being that I found a good deal on the carb and it was not set up for this motor.
I would be very appreciative if somebody fill me in on what slide, pilot and main seems to work well.
Thanks,
Troy
I have, on TZ250s, but they don't make the rather excellent Lectrons anymore. EI ain't the same thing, close, though. What I really liked about the Lectrons was they were awesome easy to jet. Needle did everything but half throttle up was boosted by the power jet.Quote:Originally posted by Bryan Norton:
FWIW I've never ran a power jet on any of my 2 strokes...
80cc or RZ350
I have, on TZ250s, but they don't make the rather excellent Lectrons anymore. EI ain't the same thing, close, though. What I really liked about the Lectrons was they were awesome easy to jet. Needle did everything but half throttle up was boosted by the power jet.Quote:Originally posted by Bryan Norton:
FWIW I've never ran a power jet on any of my 2 strokes...
80cc or RZ350
Troy, the 28-29mm carb is what comes on an RS125. I think a carb that size would horribly overcarburate an 80. When I ran the 80 with Tom Hoover (tuner extraordinaire and owner of TECC Racing and YSR Express-three mini endurance overall championships and a long-held (until recently) 80 sprint lap record), I think we ran a 24mm Keihin PWK. Too big a diameter causes too low an intake flow velocity and, subsequently, compromises the Venturi Effect and proper fuel atomization that makes a carburetor work properly.
Troy, the 28-29mm carb is what comes on an RS125. I think a carb that size would horribly overcarburate an 80. When I ran the 80 with Tom Hoover (tuner extraordinaire and owner of TECC Racing and YSR Express-three mini endurance overall championships and a long-held (until recently) 80 sprint lap record), I think we ran a 24mm Keihin PWK. Too big a diameter causes too low an intake flow velocity and, subsequently, compromises the Venturi Effect and proper fuel atomization that makes a carburetor work properly.
Memory fails you, I think, CE. The GP 125s come with 38mm carbs - Mikuni TMXs with PJs on the TZs, and Keihin 38s with PJs on the RSs.Quote:Originally posted by Chuck Ergle:
Troy, the 28-29mm carb is what comes on an RS125. I think a carb that size would horribly overcarburate an 80. When I ran the 80 with Tom Hoover (tuner extraordinaire and owner of TECC Racing and YSR Express-three mini endurance overall championships and a long-held (until recently) 80 sprint lap record), I think we ran a 24mm Keihin PWK. Too big a diameter causes too low an intake flow velocity and, subsequently, compromises the Venturi Effect and proper fuel atomization that makes a carburetor work properly.
On the 80s we ran (granted, finishing mostly runner-up to you guys, except in '97 when we won the c'ship), a 28mm Mikuni flat slide for a while and then switched to a 28mm PWK Keihin for later years. As you know from first hand experience, CE, our bike never had perfect carburation -- but using a 24mm carb on an 80 motor will be choking it.
What works best and most reliably? Well, after many years on the bikes and bunch of top finishes (and some wins and DNFs thrown in there, too), I cannot answer this question for sure.
Memory fails you, I think, CE. The GP 125s come with 38mm carbs - Mikuni TMXs with PJs on the TZs, and Keihin 38s with PJs on the RSs.Quote:Originally posted by Chuck Ergle:
Troy, the 28-29mm carb is what comes on an RS125. I think a carb that size would horribly overcarburate an 80. When I ran the 80 with Tom Hoover (tuner extraordinaire and owner of TECC Racing and YSR Express-three mini endurance overall championships and a long-held (until recently) 80 sprint lap record), I think we ran a 24mm Keihin PWK. Too big a diameter causes too low an intake flow velocity and, subsequently, compromises the Venturi Effect and proper fuel atomization that makes a carburetor work properly.
On the 80s we ran (granted, finishing mostly runner-up to you guys, except in '97 when we won the c'ship), a 28mm Mikuni flat slide for a while and then switched to a 28mm PWK Keihin for later years. As you know from first hand experience, CE, our bike never had perfect carburation -- but using a 24mm carb on an 80 motor will be choking it.
What works best and most reliably? Well, after many years on the bikes and bunch of top finishes (and some wins and DNFs thrown in there, too), I cannot answer this question for sure.
Chuck,
The PWK 28 is what all the motocross guys say to run on the 80. Your right Linz, the 38 is what the 125 runs.
Anyhow I think I am gonna call my boyz for some tuning help here pretty soon now that I have all the peices to make this thing work.
Brett...Dusty... are you guys out there???
Chuck,
The PWK 28 is what all the motocross guys say to run on the 80. Your right Linz, the 38 is what the 125 runs.
Anyhow I think I am gonna call my boyz for some tuning help here pretty soon now that I have all the peices to make this thing work.
Brett...Dusty... are you guys out there???
Duhhh. They say the memory is the first thing to go...
Duhhh. They say the memory is the first thing to go...
Who's Chuck Ergle????
Who's Chuck Ergle????