I have a 2003 DRZ125, recently jetted it from the stock 102.5 main and 17.5 pilot, to a 105 main and a 22.5 pilot. Prior to the jetting, and still, the bike tends to bog while in the air, especially if you pin it. The recent jetting seemed to help it a bit, but i do still get the bog while in the air. Any tips and/or suggestions?
DRZ125 Jetting/Air Mixture Problems
Started by ktmracer41, Nov 05 2009 09:48 AM
3 replies to this topic
Posted 05 November 2009 - 09:48 AM
I have a 2003 DRZ125, recently jetted it from the stock 102.5 main and 17.5 pilot, to a 105 main and a 22.5 pilot. Prior to the jetting, and still, the bike tends to bog while in the air, especially if you pin it. The recent jetting seemed to help it a bit, but i do still get the bog while in the air. Any tips and/or suggestions?
Posted 08 November 2009 - 04:58 PM
Fellow Thumpers,
Bought my 13 year old daughter a new 2007 DRZ125L. She weighs 96
lbs and is a fairly aggressive rider. (The apple doesn't fall far from the
tree).
We live in Colorado and ride at 4000-9000 ft above
sea level at 40 - 90 deg F. Jetting described is for
these conditions.
Made the following mods with great results for this
bike:
1) BBR Fork Springs and Shock spring, this was the
most useful mod for handling, the stock suspension is
WAY too soft and makes the bike barely ridable.
2) BBR Frame cradle, stiffens the frame and protects
the engine much better than stock plastic guards.
3) BBR "D" pipe and header, stock pipe is heavy and
bottles up the bike, makes it run like a turtle. blah
You can get the BBR bits at www.bbrmotorsports.com or
www.mawonline.com.
Engine and Jetting:
4) Open up the airbox, take the seat off and
remove the rubber snorkle from the
air box. Take a 1" dia hole saw bit and
drill 2 to 3, 1" holes in the top of the airbox.
5) Added a K&N Hi-Flow Air Filter
6) Added ProCycle jet kit for the
carb.
Bought filter and Jet kit at
www.procycle.us
I have a 20 Pilot Jet and a
107.5 Main Jet installed. I have the pilot
screw set at 2.5 turns out from lightly
seated.
The Procycle jet kit comes with an adjustable
needle, I have the clip at the middle position.
To adjust the pilot screw you need to remove
the brass plug covering the screw on the carb.
Remove the carb from the bike, and locate the
plug. It is next to the notch on the
float bowl. CAREFULLY, drill a tiny hole in the
center of the plug. Insert a steel pin or
punch in the plug and pull it out to
expose the pilot screw.
The stock jetting for this bike is very, very
lean. With the stock 17.5 pilot jet, it was
hard to start and barely idled.
The 20 pilot is great, easy starting and
smooth idle and good off-idle snap. 107.5 main gives
smooth power from 1/4 thottle to wide open.
This combination of settings was arrived at
after much experimentation and works great
from track to mountains. Tons of power
& torque compared to stock and we have never
fouled a plug.
Only additional mod we are considering is replacing
the rear sprocket from stock 57T to 51T, stock
sprocket is too short and makes 1st gear
way too low. Bike has enough torque to
easily handle taller sprocket.
All the parts listed were under $500 and totally
tranformed this bike. Work was easy, only
special tool you need is a spring compressor to
change the shock spring.
If you are at sea level with this setup,
I would use the 22.5 pilot and a 110 or
112.5 main.
Hope this helps. :thumbsup:
Bought my 13 year old daughter a new 2007 DRZ125L. She weighs 96
lbs and is a fairly aggressive rider. (The apple doesn't fall far from the
tree).
We live in Colorado and ride at 4000-9000 ft above
sea level at 40 - 90 deg F. Jetting described is for
these conditions.
Made the following mods with great results for this
bike:
1) BBR Fork Springs and Shock spring, this was the
most useful mod for handling, the stock suspension is
WAY too soft and makes the bike barely ridable.
2) BBR Frame cradle, stiffens the frame and protects
the engine much better than stock plastic guards.
3) BBR "D" pipe and header, stock pipe is heavy and
bottles up the bike, makes it run like a turtle. blah
You can get the BBR bits at www.bbrmotorsports.com or
www.mawonline.com.
Engine and Jetting:
4) Open up the airbox, take the seat off and
remove the rubber snorkle from the
air box. Take a 1" dia hole saw bit and
drill 2 to 3, 1" holes in the top of the airbox.
5) Added a K&N Hi-Flow Air Filter
6) Added ProCycle jet kit for the
carb.
Bought filter and Jet kit at
www.procycle.us
I have a 20 Pilot Jet and a
107.5 Main Jet installed. I have the pilot
screw set at 2.5 turns out from lightly
seated.
The Procycle jet kit comes with an adjustable
needle, I have the clip at the middle position.
To adjust the pilot screw you need to remove
the brass plug covering the screw on the carb.
Remove the carb from the bike, and locate the
plug. It is next to the notch on the
float bowl. CAREFULLY, drill a tiny hole in the
center of the plug. Insert a steel pin or
punch in the plug and pull it out to
expose the pilot screw.
The stock jetting for this bike is very, very
lean. With the stock 17.5 pilot jet, it was
hard to start and barely idled.
The 20 pilot is great, easy starting and
smooth idle and good off-idle snap. 107.5 main gives
smooth power from 1/4 thottle to wide open.
This combination of settings was arrived at
after much experimentation and works great
from track to mountains. Tons of power
& torque compared to stock and we have never
fouled a plug.
Only additional mod we are considering is replacing
the rear sprocket from stock 57T to 51T, stock
sprocket is too short and makes 1st gear
way too low. Bike has enough torque to
easily handle taller sprocket.
All the parts listed were under $500 and totally
tranformed this bike. Work was easy, only
special tool you need is a spring compressor to
change the shock spring.
If you are at sea level with this setup,
I would use the 22.5 pilot and a 110 or
112.5 main.
Hope this helps. :thumbsup:
Posted 10 November 2009 - 08:00 PM
Thanks for your reply, but im still looking for advice about the bog while in the air
Posted 14 November 2009 - 03:54 PM
If the bike is bogging in the air (no load on
the transmission) and especially at
full throttle, it is probably still a bit rich.
The main jet kicks in at just over 1/4
throttle thru full throttle.
Couple of suggestions:
1) Open up the air box and
get a K&N hi-flow air filter.
More air = more lean
2) Go down one size on the main
jet or for finer adjustment, if you
have an adjustable needle, move
the needle down 1 or 2 slots.
ie; Move the clip up 1 or 2
positions. This will lean it out
a bit at full throttle.
3) Also may want to try a hotter
plug. I run the NGK IX Iridium plug
in this bike (DR8EIX). A bit more expensive
(like $7) but makes a hotter
spark and is easier to start. Also
I have never had one foul on me.
Hope this helps.
the transmission) and especially at
full throttle, it is probably still a bit rich.
The main jet kicks in at just over 1/4
throttle thru full throttle.
Couple of suggestions:
1) Open up the air box and
get a K&N hi-flow air filter.
More air = more lean
2) Go down one size on the main
jet or for finer adjustment, if you
have an adjustable needle, move
the needle down 1 or 2 slots.
ie; Move the clip up 1 or 2
positions. This will lean it out
a bit at full throttle.
3) Also may want to try a hotter
plug. I run the NGK IX Iridium plug
in this bike (DR8EIX). A bit more expensive
(like $7) but makes a hotter
spark and is easier to start. Also
I have never had one foul on me.
Hope this helps.
