CR250 surging idle

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Mar 24, 2006
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#1
well like the title says, im having a surging idle issue. im looking at a lean condition. just replaced both crank seals. didnt fix it. replaced the reed cage gaskets, no dice. i have a JD jetting kit installed. while warming up she runs fine but once hot shes got a surgng idle. also at wot she runs fine but after you come down back to idle the surging begins. anyone have any other ideas on what to look for?
 
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Nov 17, 2005
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#3
I was having the same problem with my 97 CR250. Surges on idle after riding, but then levels out to a nice idle after 30-40 seconds. By idle I mean having to blip the throttle every 10 seconds to keep it from stalling. Last weekend it stalled and has not restarted since then. I am now replacing my reed valve because it was cracked. I am also cleaning the carb. I will get back to you if I find anything out. I posted the same question a few weeks back and got a variety of responses, you may want to do a search for "cr250 surge".
 
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#4
The cylinder base gasket and crankcase center gasket are also possible sources for air leaks.
 
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#5
Once you get it running, spray carb cleaner in different areas. If the idle changes, you will know where the air leak is.
 
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#6
i spreayed WD around every gasket area, nothing. also have a V-force reed cage, ive heard they love leaking so thats my next place to check. what do you all think the likelyhood of the cases leaking where the 2 halves meet? i noticed a small amount of tranny oil leaking out of there.
thanks for the help guys
 

RM_guy

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Damn Yankees
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#8
Did you try to turn in the air screw to make it richer?
 
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#9
ZOMBIE666 said:
...what do you all think the likelyhood of the cases leaking where the 2 halves meet? i noticed a small amount of tranny oil leaking out of there...
That would be a good place to look. If you have leakage in the trans area, there's a good chance you have it in the crank area. How likely it is to occur is directly proportional to the care used in prepairing the mating surfaces and installing the case halves.

Marc -