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How do you know when you're running lean?

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How do you know when you are running lean without a spark plug test? Any other symptoms? I may just be paranoid but I wanted to know what to look out for. My bike does smoke some and has some black coming out the exhaust but idk of that's enough to tell you your not running lean.

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Black is gas

White is oil

Sweet is coolant burning

 

It would help to know the kind of bike......and maybe the model......

 

You can still do a plug chop. You just need to use non-pump gas.

The problem is you have to really do it right to make it mean anything, and know how to read it. 

The 'color of the plug' is not what you are looking for......

 

http://www.braigasen.com/howtoread.htm

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How do you know when you are running lean without a spark plug test? Any other symptoms? I may just be paranoid but I wanted to know what to look out for. My bike does smoke some and has some black coming out the exhaust but idk of that's enough to tell you your not running lean.

 

There are telltales.... 

 

- When you close the throttle after a high rpm run and the bike is decelerating under engine braking....if it "pops" on the way down this is a symptom of lean (on the pilot or air screw)

 

- When you close the throttle after a high rpm run and pull in the clutch yet the engine seems to "hang" at a higher rpm, rather than quickly coming back to idle this is a symptom of lean (on the pilot or AS)

 

- If the bike is thoroughly warmed up and with the bike running at idle and in neutral you "wack" the throttle wide open the engine should instantaneously rev up...if it bogs (like "Brrrrrrr") this is a symptom of lean (on the pilot or AS).

 

- If you are idling along at low rpm in gear and crack the throttle open and it sputters like it's under water this is a symptom of rich (on the pilot and or jet needle)

 

- If with the bike fully cooled off you can easily start the bike with the choke off then the pilot may be rich

 

- If the bike is thoroughly warmed up and idling and you pull the choke on, the bike should instantly die....if it doesn't, or even increases it's idle speed, the pilot may be lean

 

- If the bike "loads up" excessively during long, very slow, low rpm riding, then the pilot circuit may be rich

 

- If your rad cap pukes coolant after only short duration very low speed, low rpm riding then your pilot may be lean

 

- Looking for plug insulator color is more of a MJ thing

 

- Then there's all the other more obvious things you hear to watch for like excessive spooge, smoking, etc...

 

Essentially three circuits are at play and it's possible to be rich on one and lean on the other:

 

- Pilot.....controls closed to 1/4 throttle

 

- Jet needle.....controls 1/4 to 3/4 throttle

 

- Main jet....controls 3/4 to full throttle

 

If you ride a big bore 2 stroke then the pilot and needle come into play more.  If you ride a small bore than MJ is more of concern (generally speaking and not considering riding style).  Because typically a big machine is lugged in the lower rpm whereas a small bore spends more time on the pipe ;) (Not considering sand, snow bike, etc...applications)

 

Personally I think the best way to jet a bike is by throttle response and feel, but I'm no expert......just some things I've learned...

Edited by Fattonz
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The bike is an 01 Honda cr250. I was told my JD jetting to switch to the red needle 3rd clip from blue needle 3rd clip. Because of bogging from 1/4 to 1/2 throttle. However, I also replaced some funky reeds which I heard can imitate a rich condition. I am just a little concerned if now I'm running lean. I haven't had any problems so far I've been ripping the hell out of it. The bog is also gone.

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There are telltales....

- When you close the throttle after a high rpm run and the bike is decelerating under engine braking....if it "pops" on the way down this is a symptom of lean (on the pilot or air screw)

- When you close the throttle after a high rpm run and pull in the clutch yet the engine seems to "hang" at a higher rpm, rather than quickly coming back to idle this is a symptom of lean (on the pilot or AS)

- If the bike is thoroughly warmed up and with the bike running at idle and in neutral you "wack" the throttle wide open the engine should instantaneously rev up...if it bogs (like "Brrrrrrr") this is a symptom of lean (on the pilot or AS).

- If you are idling along at low rpm in gear and crack the throttle open and it sputters like it's under water this is a symptom of rich (on the pilot and or jet needle)

- If with the bike fully cooled off you can easily start the bike with the choke off then the pilot may be rich

- If the bike is thoroughly warmed up and idling and you pull the choke on, the bike should instantly die....if it doesn't, or even increases it's idle speed, the pilot may be lean

- If the bike "loads up" excessively during long, very slow, low rpm riding, then the pilot circuit may be rich

- If your rad cap pukes coolant after only short duration very low speed, low rpm riding then your pilot may be lean

- Looking for plug insulator color is more of a MJ thing

- Then there's all the other more obvious things you hear to watch for like excessive spooge, smoking, etc...

Essentially three circuits are at play and it's possible to be rich on one and lean on the other:

- Pilot.....controls closed to 1/4 throttle

- Jet needle.....controls 1/4 to 3/4 throttle

- Main jet....controls 3/4 to full throttle

If you ride a big bore 2 stroke then the pilot and needle come into play more. If you ride a small bore than MJ is more of concern (generally speaking and not considering riding style). Because typically a big machine is lugged in the lower rpm whereas a small bore spends more time on the pipe ;) (Not considering sand, snow bike, etc...applications)

Personally I think the best way to jet a bike is by throttle response and feel, but I'm no expert......just some things I've learned...

Black is gas

White is oil

Sweet is coolant burning

It would help to know the kind of bike......and maybe the model......

You can still do a plug chop. You just need to use non-pump gas.

The problem is you have to really do it right to make it mean anything, and know how to read it.

The 'color of the plug' is not what you are looking for......

http://www.braigasen.com/howtoread.htm

The bike is an 01 Honda cr250. I was told my JD jetting to switch to the red needle 3rd clip from blue needle 3rd clip. Because of bogging from 1/4 to 1/2 throttle. However, I also replaced some funky reeds which I heard can imitate a rich condition. I am just a little concerned if now I'm running lean. I haven't had any problems so far I've been ripping the hell out of it. The bog is also gone. Also it's white smoke. Thanks guys.

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I just switched back to the blue. No longer idles so high and no bog still. My guess it may have been running a little bit lean. Performance is still good so I am going to keep it blue 3rd clip. My best guess was that it was the reeds. For future reference for anyone else who does this make sure you check your reeds first because it is true that they can imitate a rich condition and make your bike bog.

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