okiebob
Adjunct
Reged: 05/13/07
Posts: 201
Loc: Oklahoma City, Oklahoma
|
|
Could you please explain this throttle position thing again for me. I am a little confused as to how it really relates to speed and rpm.

Thanks in advance, Bob
-------------------- 2003 Speedmaster
I won't rise to the occasion, but I'll slide over to it.
|
greentp99
Member
Reged: 01/15/07
Posts: 64
Loc: New Jersey, USA
|
|
From what i have been able to learn here...even through the sarcasm ... is that throttle position(1/8th turn, 1/4 turn, 1/2 turn, WOT) is not relevant or relative to speed or RPM when measuring performance(HP/Torque)BUT how well the fuel to air mixture happens in the carb. Basically what you are looking at is the ability to consistently generate the proper mixture so you can take advantage of it at any speed or rpm... I think that's it anyway
-------------------- Ralph Muro
'06' TBA / Tach / Freak / BUB Slash Cuts / TBS Needles with shims / 150 jets / 45 pilots / 440s / Rivco Risers / Corbin Solo / Dresser Bars / CHROME...CHROME...CHROME...
|
Cowtipper
Learned Hand
Reged: 07/22/06
Posts: 1337
Loc: Fort Worth Texas
|
|
Quote:
From what i have been able to learn here...even through the sarcasm ... is that throttle position(1/8th turn, 1/4 turn, 1/2 turn, WOT) is not relevant or relative to speed or RPM...
Correct
Quote:
...when measuring performance(HP/Torque)BUT how well the fuel to air mixture happens in the carb. Basically what you are looking at is the ability to consistently generate the proper mixture so you can take advantage of it at any speed or rpm... I think that's it anyway
Yes, but why (or rather, how) is the question. Measuring the throttle position allow you to target the specific components of the carburator system. The carbs deliver fuel through a series of point. Closed throttle to about 1/4 throttle is mostly the pilot system, 1/4 to 1/2 is mostly the needle jet, 1/4 to 3/4 is the jet needle, 3/4 to WOT is the main jet.

The reason for using throttle position is to isolate the individual parts of the fuel delivery circuit for tuning to maximum efficiency.
Here is a pretty good web page....http://www.dansmc.com/carbs2.htm
Clear as mud?
-------------------- 2002 Bandit 1200/ GSXR cams/ 1277 BB Kit/ Holeshot header and can/ 38mm flatslides/ a good head/lotsa hp/lotsa tq- lots of rear tires...
|
moe
Bearing Changer
Reged: 01/11/05
Posts: 9829
Loc: Merritt Island, Fl
|
|
Quote:
Arrrrghhhh!  I don't mind answering questions at all, don't misinterpret this, but read read read!
I must get 4-5 emails everyday asking the same general questions...."What jets at this rpm? What jets at this speed??? My bike runs bad when I am in 5th gear??"
Setting up carbs is done by using the throttle position! DO NOT use a specific RPM range or a certain speed. They will do nothing but get you confused and possibly into trouble.
Read this CVK Tuning guide (same as ours but a larger carb - STILL the same) AND the Mikuni Tuning Guide for reference on how to actually use the throttle with small pieces of tape for markers.
It's not rocket science (unless you want it to be). If I can do it, so can anyone else just by following the steps outlined in these pages.
Throttle position is the secret!
Ok, rant over, and it's beer thirty.
This CVK Tuning guide (same as ours but a larger carb - STILL the same) is dead.
This mud_dog450 is alive.
this is not Thu Apr 13 2006 07:16am: this is beer thirty for all yous throttlepostitionmeisters.
-------------------- Blowing gravel off rural roads
|
Bluesbass
Adjunct
Reged: 01/15/05
Posts: 390
Loc: Earth, Quadrant B2, Grid 4A
|
|
OK...so...I've completely lost track of all the people I used to love chatting with here because I'm lame and just don't get here anymore the way I used to...and out of nowhere I get a reply in my inbox to a post I just KNOW I read ... like... a LONG time ago. Do we really have to teach the newbies about the deadthreads and archive? And this is supposed to be the computer savvy generation? Jeesh 
BB
-------------------- Patriotism: Supporting your country all the time and your government when it deserves it. M. Twain
|
Bluesbass
Adjunct
Reged: 01/15/05
Posts: 390
Loc: Earth, Quadrant B2, Grid 4A
|
|
And...Moe...nice to hear / see your name again. BB
-------------------- Patriotism: Supporting your country all the time and your government when it deserves it. M. Twain
|
arstaren
Loquacious
Reged: 07/23/07
Posts: 3474
Loc: Southeast ,Iowa, USA
|
|
I love this site for various reasons. This thread brings to mind two. The plainly funny fellas and their good natured ribbing, and the fact that I can learn just enough here to know I'm never gonna understand some of the mechanics of my new America so I'm gonna continue to really like the mechanics of my old Triumphs. You guys are a hoot.
-------------------- Fidelis et Fortis
|
moe
Bearing Changer
Reged: 01/11/05
Posts: 9829
Loc: Merritt Island, Fl
|
|
BB,
every time i see horse manure in the road i think of Mennonites,...and you. jeez some association huh? keep on rocking brother.
-------------------- Blowing gravel off rural roads
|
Bluesbass
Adjunct
Reged: 01/15/05
Posts: 390
Loc: Earth, Quadrant B2, Grid 4A
|
|
Moe,
Heheh...and I presume I should be thanking you for this compliment? 
BB
-------------------- Patriotism: Supporting your country all the time and your government when it deserves it. M. Twain
|
Grzegorz
Freelance Jedi Knight
Reged: 09/03/05
Posts: 3582
Loc: Poland-Gdansk!!! UK-Oadby
|
|
links not working
-------------------- Grzegorz ......55 cubic inches
http://www.flickr.com/photos/25172906@N06/ 904 Wiseco,813 TPUSA cams,TTP ignitor,gutted airbox,"breath" air intake,Keihin CR-S carbs,Black Epco exhaust,SS wheels
|