Motorcycle-Journal Forums  

Go Back   Motorcycle-Journal Forums > Bike Talk > Dirt Bikes & ATV's
Motorcycle Journal       Suzuki Bikes       Honda Bikes       Yamaha Bikes

Dirt Bikes & ATV's Ride a dirtbike, dualsport or ATV? Tell us all about it here!


Welcome to the Motorcycle-Journal Forums forums.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.
Reply
 
LinkBack Thread Tools
Old 05-09-2007, 08:58 PM   #1 (permalink)
Newbie
 
BodaciousNick's Avatar
 
Joined: May 2007
Bike: 1980 RM 125
Location: Crystal River, FL. good ol' USA
Posts: 16
Send a message via AIM to BodaciousNick
Default RM 125 carb issues.

Hey, im the owner of a 1980 RM 125. just recently ate the piston and had to repair a few things. thats all done, and the bike is broken in...but the bike has been running really rich with fuel, always has, but it seems a lil' worse now, and might as well fix it since the engine is all in good order now. the mixture ratio is 32:1, which is even more lean than the 20:1 ratio that the clymer book for my bike suggests. I was wondering. does overboring the engine change the dynamics of the carb? I was snooping around the nature coast power sports website and noticed that there is more than one type of jet sets for my carb. i was thinking, are the other jets for various over bore sizes? I have re-adjusted the floats to cut off fuel sooner and it still loads up it seems. I am using good pre-mix oil and gasoline with a 93 octane rating. not the best...but pretty good. maybe i need to adjust the throat needle? im not the sharpest tool in the shed when it comes to tunning a carb...but i can find my way around. any help you can offer would be great. thanks for your time.

~nick

BodaciousNick is offline   Reply With Quote
Sponsored Links
Suzuki Motorcycle Info  Honda Motorcycle Pictures  Kawasaki Motorcycle Resource  Yamaha Motorcycle
Old 05-10-2007, 01:13 AM   #2 (permalink)
Clunked into first gear
 
the_privateer's Avatar
 
Joined: Jul 2006
Bike: 2000 yz125 race prepped
Location: bentonville, arkansas, us
Posts: 230
Default

over-boring, weather, altitude, riding style, humidity, and any modifications are going to affect your jetting.

first i would set the float to the correct level, and repack the silencer if it needs it
now you need to decide where in the rev range you are rich

the pilot jet concerns 0-1/4 throttle ranges, adjustment is made by switching out different size jets

the jet needle concerns 1/4 to 3/4, adjustments are made by moving the clip on the needle, up to lean

the main controls from 1/2-to full throttle, adjusted by switching out for different size jets

a smaller jet will lean out the mixture, usually you want to make steps one size at a time to prevent going too lean and seizing the motor

if you have a manual it will make this all very easy, if not i would either get one, or go to bike bandit or some other parts site where you can get a parts fiche for the carb
the_privateer is offline   Reply With Quote
Old 05-10-2007, 06:32 PM   #3 (permalink)
Newbie
 
BodaciousNick's Avatar
 
Joined: May 2007
Bike: 1980 RM 125
Location: Crystal River, FL. good ol' USA
Posts: 16
Send a message via AIM to BodaciousNick
Default

yeah, i have a manual by Clymer. its pretty thourough. Thanks for you input. it seems that the exhaust becomes smokiest at the low rpms. close to idle. I have cleaned EVERYTHING! though i live down in FL and the fires in GA have been making it really smokey and cloudy. its also very humid as well. so maybe that leap in climate change is to blame, at least for some part.

Im pretty sure that the pilot jet will be the one to go. ill consult my manual a little more and see what it says. Thanks for your reply!
__________________
Because football, soccer, and baseball require only one ball.
http://www.myspace.com/space_nicks_is_this
BodaciousNick is offline   Reply With Quote
Old 07-08-2007, 09:08 PM   #4 (permalink)
Newbie
 
Harry Palmer's Avatar
 
Joined: Jul 2007
Posts: 17
Default

Try Reading the spark plug,32-1 is alright,93 octane is great,use your manual to confirm your air,fuel screw settings,set your needle clip at the top,All the
smoke your seeing could be from a weak right side crank seal,Drain your trans
oil and measure what you put back in,Ride it like you stole it,for an hour or two
Then redrain and measure what comes out. NO REFEREES NO TIMEOUTS!
Harry Palmer is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
1988 / GSX600F Carb issues / Leaking fuel after rebuild baretree Mechanics Corner 5 06-29-2008 07:02 PM
1977 ds 185 carb issues racerd14666 Dirt Bikes & ATV's 6 03-26-2007 10:19 PM
Mikuni Carb issues jmensch Mechanics Corner 10 01-23-2007 06:25 PM
Issues usampson Mechanics Corner 0 09-19-2005 06:21 PM


All times are GMT -5. The time now is 09:28 PM.
Blackbird Forums


Copyright 2008, Suzuki-Bikes.com
Motorcycle-Journal Forums

SEO by vBSEO ©2008, Crawlability, Inc.