2 Stroke CR 125 01 Fouling spark plugs

M

madguru100

Ok well i just found out that the standard carbs were tmx if got a Keihin PJ 35mm . 172 Main jet and 60 pilot jet float height should be adjusted properly now its nice and parallel . Average temparture here is around 18 to 28 degrees , Altitude around 300 any ideas if i'm too rich cause i keep fouling plugs every 20 minutes of riding i'm not sure if i cold foul them cause i usually only let it warm up for 20 seconds then i'm on the throttle .
 
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O

ossagp

that is for the stock mikuni. first you need to detemine what carburetor you have, ie 36, 38. pj version, or pwk version. to tell the difference in the pwk go look at the carb at bikebandit.com for a 2000 honda cr250r. compare it to yours and look up a 95 cr125r at the same place. pay attention to the slide and see if there is an actual adjusting screw that moves the slide up and down on yours. the pj version doesnt have such a screw and the side of the slide is rounded and about 3/8" thick. the pwk has a square edged slide that is less than half that thick. we can work from there. drenching it doesnt sound like jetting and we can work on the other ways to test for leaks at the float.
 
O

ossagp

if you have the pj the idle gets set by turning up and down on the choke knob. if you are fouling plugs try this: push the knob (actually called an enrichening knob) down fully. then screw it down firmly. age old problem with that carburetor. they bleed as they age at the enrichening valve. dont bother to buy a new plunger for it, in my experience they do little good.
 
M

madguru100

Its definetly a pj i'm not sure if its a 36mm or a 38mm . The idle is controlled from the choke knob so you think its not from the jetting but the float? I checked the needle of the float and the float height and all is good
 
M

madguru100

ossagp:
if you have the pj the idle gets set by turning up and down on the choke knob. if you are fouling plugs try this: push the knob (actually called an enrichening knob) down fully. then screw it down firmly. age old problem with that carburetor. they bleed as they age at the enrichening valve. dont bother to buy a new plunger for it, in my experience they do little good.
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I'll try this thanks mate
 
M

madguru100

bobkyle2:
If its a 38mm , That is alot of carb for a 125..... And those are about the same jets i run in my 250 if i remember correctly. Hate those carbs 100%
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It must be a 34 mm but yea i think the jetting is way too rich any ideas to what jets i should try? It fouls at 1/4 to 3/4 throttle and sometimes full throttle so i think i need to go down a notch on the needle and the main jet?
 
O

ossagp

bobkyle2:
If its a 38mm , That is alot of carb for a 125..... And those are about the same jets i run in my 250 if i remember correctly. Hate those carbs 100%
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after about 2000 they all came with 38's it seemed. my 99yz 125 was the first one i had that did.
 
O

ossagp

madguru100:
If got a keihin 34mm carb just checked sizes
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Did you try turning the choke knob down. the only jet that seems like it may act too rich to me is the 60 slow jet, and we ran 40-55's depending on the weather/temp on the mid 90's cr125s. you need to check to make sure that the fuel is actually shutting off though.
 
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