Dirt Bike Repair & Maintenance Forum

Hello everybody.My 2002 cr250r is fouling plugs every ride, and it is getting harder to start maybe 15+ kicks. Last ride after 1 hour of riding i turned it off for a minute and couldnt get it started so after several hard kicks it finally started. Im using spark plug B8ES, but stock it says to use BR8EG. Should i go back to stock plug or is there another one i should use? My air filter is dirty so i have to replace the air filter. Should i do all of this before messing around with my carb. Im not sure what the pilot and the main is yet on the carb. Should i find out? I dont know what the setting of the air screw is. I was going to reset the air screw to the manual specs today. My elevation is 50 m (164 ft)in the city but a little higher where i ride. I ride trails and logging roads. Any help will be greatly appreciated.  

find out what you got for jets. also what oil mix you running? your running oil rich, whether its a carb issue or a fuel mix issue i dunno. some of it is rideing as well. ~pat  
PEACE GUYS ITS BEEN A BLAST!!!!! ~patrick

hey, im mixing .379 litre(12.8 FL. OZ.)of bel-ray MC-1 synthetic engine oil with 13.8 liters of gas.Not sure the ratio on that. Im switching to 92 octane from now on (the highest i can get here in canada). Looking at main today in the carb will tell ya later tonight.  

your mix is good. about 36:1 i believe. im not a jetting person but there are a few carb geniuses on here that will be on later. so find out and post and they'll get you set up in no time. ~pat  
PEACE GUYS ITS BEEN A BLAST!!!!! ~patrick

My main jet is 420, and my slow jet/pilot jet is 42, jet needle clip position is the 3rd groove, and the pilot air screw turns out is 1 3/4. Do i need to change anything to fit my elevation?  

ok before you start rejetting your bike, change your oil. that oil you are using is complete crap. do not use it. this oil is really bad on your engine.

use bel ray h1r, or honda hp2, or yamalube 2r. mixed at 32:1.

your top end may be getting worn or it could be your jetting. since you live in canada im guessing that the temperature has dropped dramatically in the past few weeks. so your bike should be running lean because the temperature dropped. but you should not be fouling plugs. your bike is doing the opposite of what it should be. which also give me reason to beleive your top end is going.

so here is what to do. clean the air filter. stock filters are cleanable and so are most aftermarket filters. just use soap and water, and treat it with air filter oil before reinstalling it. a dirty air filter will mess up your jetting big time. and also the air screw is not something you set and just leave it at that. it needs adjusted on a daily basis.

so if your bike is still running bad after you install a clean air filter and chagne your premix to one of the three i mentioned, then tell us how it is running, and we need to know how it runs at different throttle position. ex. idle, 1/4, 1/2, 3/4, and wide open. and also the color of the plug.  
______________________________
Ride 2 strokes, buy 2 strokes, save the 2 stroke.

1998 cr125
2002 cr80

Hello, i'll do what you stated and get back to you within 3 or so days. But what should i do about my spark plug stay with the B8ES or go to stock which is BR8EG. Also, how do you set the air screw daily. Is 15+ kicks normal after the bike sitting for 1 week, and hard to start after 1 hour of riding or is the top end getting weak like you said.  

it should start first kick no mattter how long its been sitting. and use the stock plug.

to start while the bike is cold. turn choke on. kick while giving it no throttle. it should start between 1-5 kicks. do very small light blips of the throttle. i'm talking like less then 1/8 turn of the throttle. my manual says to do hold the throttle and gradually increase it, i found this fouls the spark plug. well once you get a clean responce turn the choke off and let it warm up the same way for at least another minute or until you can tell that the bike is running cleanly.

when starting after warm-up. choke should be off. kick with the thottle slightly turned. and it should start with 1-5 kicks. the less kicks it takes the better. my bike usually starts after the fist kick no matter how long its been sitting.

and when you are done riding turn the gas off and lay the bike on its side so the gas drains out the carb bowl. and before you go to start it always shake your bike to mix the the gas inside the tank.

to set the air screw. let the bike fully warm up. and turn the air screw out or in until you get peak rpm. or best throttle responce. it should not bog at low rpm but it should not bog when you snap the thottle wide open. if you use that technique then you need to find a happy medium. but if you use an odometer, i think its called, to find the peak rpm, that is the easiest and most accrurate way.  
______________________________
Ride 2 strokes, buy 2 strokes, save the 2 stroke.

1998 cr125
2002 cr80

Thanks elko6 so far your helping alot. oh and elaborate a little more on this please"and when you are done riding turn the gas off and lay the bike on its side so the gas drains out the carb bowl".  

just simply turn the fuel off at the fuel petcock and lay the bike on its side. you will see fuel coming out from a hose under the bike. when you do this you are draining all the gas out the carburater. when you let gas sit in the carburater it can gum up and make the bike hard to start and cause other problems.  
______________________________
Ride 2 strokes, buy 2 strokes, save the 2 stroke.

1998 cr125
2002 cr80

does it matter which side to tilt the bike.  

nope, i only do that if im gonna not start my bike for like a couple weeks though. or when my bike gtes flooded really bad. your bike probably has a topend issue, it seems like it wont start very well in any circumstance. seems like it could be a worn topend. ~pat  
PEACE GUYS ITS BEEN A BLAST!!!!! ~patrick

Well usually you dont tilt a bike over to get the gas out of the bowl there is a overflow it comes out of that.Clean your air filter and the air box you will see a difference trust me Check out your reeds.Well your only suppose to use a B8 Spark plug if its worked or if you race alot and your always in powerband!  
87'Ktm250
88'CR250R
89'Rm250
old bikes
98'xr80r
87'cr80r
81'cr125r
82'yz100

Does your compression feel good if you can push down your kick start with your arm without putting all of your muscle into it then its time for a rebuild!  
87'Ktm250
88'CR250R
89'Rm250
old bikes
98'xr80r
87'cr80r
81'cr125r
82'yz100

2strokez1:
Well usually you dont tilt a bike over to get the gas out of the bowl there is a overflow it comes out of that.Clean your air filter and the air box you will see a difference trust me Check out your reeds.Well your only suppose to use a B8 Spark plug if its worked or if you race alot and your always in powerband!

well first off not to be an ass but dont contradict what i am saying unless you know what your talking abnout. you say to you usually dont have to tilt a bike over to get the gas out of the bowl and there is an overflow it comes. to get the gas to come out the overflow tubes you need to tilt the bike over. there is a drain screw on the carb but this way is a lot easier and quicker.

if you have gas coming out your overflow  tubes without the bike laying over then your floats are set wrong.  
______________________________
Ride 2 strokes, buy 2 strokes, save the 2 stroke.

1998 cr125
2002 cr80