So yesterday I started up my bike to see how it idled so I could see if it idled because I had time and would had time to adjust the carb if needed. So I started it up cold and it ran but only if I gave gas if I dident it would bog out. I was thinking I could just adjust the idle screw but I want to know if it's going to damage my bike or anything... Is the one I need to adjust the screw right above the letters PE on it or the small one to the left of the letters PE
Need some Help
- Thread starter ThrottleHappy
- Start date
So Idle adjustment involves BOTH of those screws.
One is idle mix, one is idle speed.
The one in the middle above the letters PE is the Speed Screw.
The One off to the left of the PE is an Idle Mix Screw (Controls Air)
1. First get the bike completely warmed up. So that you cannot touch the engine with a bare hand.
2. Set the Idle Speed screw so that the bike has a high idle.
3. Turn the mix screw IN (Leaning) until the idle rpms 'peak.' Turn the screw back out 1/8th of a turn from where the engine rpm peaked.
4. Turn the Idle Speed screw back down to the appropriate idle rpm.
5. RIDE
One is idle mix, one is idle speed.
The one in the middle above the letters PE is the Speed Screw.
The One off to the left of the PE is an Idle Mix Screw (Controls Air)
1. First get the bike completely warmed up. So that you cannot touch the engine with a bare hand.
2. Set the Idle Speed screw so that the bike has a high idle.
3. Turn the mix screw IN (Leaning) until the idle rpms 'peak.' Turn the screw back out 1/8th of a turn from where the engine rpm peaked.
4. Turn the Idle Speed screw back down to the appropriate idle rpm.
5. RIDE
Okay thanks Big Dan!!! When do you suggest riding (temp wise) because the weather has been really chilly like under 30 farenheit... So should I just set the idle and wait until spring?
Ride ALL DAY!!!
I ride in the snow with my air-cooled bike, no problems. -BIG DAN
https://www.youtube.com/watch?v=7v_hWVthvKo
Yeah but I haven't jetted my bike for those conditions..
No need with most bikes. It might be slightly lean, but I would give it a try! The cold air will counteract the added heat running lean causes.- BIG DAN
What bike?
Even with two strokes? ( mines 2 stroke ) . Some mechanics told me if I rode my bike In cold weather like 25 farenheit I would cold seize the engine. Which I definitely dont want
Mine is an air-cooled two-stroke, which would be far more susceptible to cold seize than any other bike. Never had an issue. -BIG DAN
SNOWMOBILES are mostly two strokes!
Here are some other two stroke examples!
https://www.youtube.com/watch?feature=player_embedded&v=xxr938oZxvw
I have a 2009 rm85
Water cooled. The water jackets act as insulation as well. You'll be more than fine in the cold! -BIG DAN
Cold seize means that your piston warms up faster than your cylinder and seizes up inside your cylinder due the fact that your piston expands at a faster rate than your cylinder. Always let your bike warm up before ripping the throttle. I taught my boys to not ride until the radiator is good and warm by hand. If the water is hot then your cylinder is hot
Alright cool! I'll set my bike up like this dan and I'll make sure to always warm it up!!! Thanks! But can you explain when u have to jet your bike because I'm really confused on what it is really..thank you though
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This would be an excellent example of when you would want to change your carburetor's jetting. When going from 70+Degree jetting to freezing temps. There are charts out there that can ballpark you given temperature or altitude change.
Some reading...
http://www.iwt.com.au/mikunicarb.htm
So for example, If you have a 150 Main jet
Your start factor is at sea level at 68*F, then your current factor is .98.
The destination Factor is at 6400ft at 50*F, then your destination factor is .94.
So a change of .04 smaller.
150*0.04=6
150-6=144
You would look for the closest jet to 144 and see if that jet circuit performs better.
Remember, these are just estimates, so you'll have to jet with your ass-dyno to fine tune it.
-BIG DAN
EDIT: lets do the math on your situation! For what conditions is the bike currently jetted?
Some reading...
http://www.iwt.com.au/mikunicarb.htm
So for example, If you have a 150 Main jet
Your start factor is at sea level at 68*F, then your current factor is .98.
The destination Factor is at 6400ft at 50*F, then your destination factor is .94.
So a change of .04 smaller.
150*0.04=6
150-6=144
You would look for the closest jet to 144 and see if that jet circuit performs better.
Remember, these are just estimates, so you'll have to jet with your ass-dyno to fine tune it.
-BIG DAN
EDIT: lets do the math on your situation! For what conditions is the bike currently jetted?
Ass and ear comboThis would be an excellent example of when you would want to change your carburetor's jetting. When going from 70+Degree jetting to freezing temps. There are charts out there that can ballpark you given temperature or altitude change.
Some reading...
http://www.iwt.com.au/mikunicarb.htm
View attachment 20437
So for example, If you have a 150 Main jet
Your start factor is at sea level at 68*F, then your current factor is .98.
The destination Factor is at 6400ft at 50*F, then your destination factor is .94.
So a change of .04 smaller.
150*0.04=6
150-6=144
You would look for the closest jet to 144 and see if that jet circuit performs better.
Remember, these are just estimates, so you'll have to jet with your ass-dyno to fine tune it.
-BIG DAN
EDIT: lets do the math on your situation! For what conditions is the bike currently jetted?
you can listen to the motor. It will talk to ya you just have to speakith the language. If it's blubbering, is rich.It's got the manafacture jets I believe... I think it's 144 and 48?