RM125 I'm back!!! with more question about carb/jetting

[badseed]

Hello again everyone....

Sorry to be a pain in the butt. However, this 2001 RM125 is driving me nuts!!!

This "bog" at take off is just driving me crazy.....(I'm ready to sell it and let someone else mess with it and just buy my son a different bike).


here's the deal....
at take off I have a awful bog....after the pilot circuit, it clears up and runs like a bat out of hell.....

Here's what I've done...
Another new plug...
(Haven't did any plug chops as it appears to be the pilot circuit I'm having problems with....but after a hour or so of riding the plug is a nice cardboard color and is NOT wet at all).
has a new air filter....
fresh gas @ 32:1
brand new clutch...
checked the timing mark on the stator (set perfect)...
rebuilt the carb (new carb kit)...and cleaned the carb I dunno 5 times now...
Float height is perfect...
This thing has the cleanest carb (inside and out) you've ever seen on a 2001.....
Did a compression test and it has 173 psi...
reeds are in excellent shape (I'm not sure but I believe they are boyesen reeds, they for sure are not stock reeds)
my air/fuel mixture screw still has zero effect on the idle?
I've dropped the pilot jet 1, 2 and 3 sizes and still no effect on the air/fuel mixture screw...

with the stock 27.5 pilot jet taking off I get a bog/gurgle/blubber....
drop it to a 25 pilot and the gurgle/blubber goes away but the bog stays...
drop the pilot to a 22.5 (same results as the 25)
drop the pilot to a 20 and it just plain runs like crap!!!
no matter what I do my air screw has no effect on the idle???

(just cruising around in any gear in the 1/8th to 1/4 throttle position the bike has a crackle/gurgle sound to it...no matter what pilot jet I'm running)

Now, if I pull the choke on while its running (engine warm) it dies....but if I pull the choke on half way and work to keep it running it appears to pull better/harder on the mid-range but the take off bog is still there/maybe even worse....

I guarantee the carb is spotless with no clogged passages....

I can't get this thing to spin the tire on take off in the damn mud.....nothing but "baaaawwwwaaaa" till after about the 1/8th to 1/4 throttle position....
I know in the mud on take off I should be able to spin that damn rear tire.....I can get them RPM's up and feather that clutch and in the mud that tire will not spin...it either bogs real bad or just plain stalls out....

what else besides a dirty carb or rich pilot jet would cause my air screw to have no effect on the idle??? (should I try riding the thing with no seat on it so it gets more air?) I dunno I'm lost.....

173 PSI on the compression test so thats telling me its not a low compression issue...
I'm not loosing any gear oil....so I assume the seal is good....
the dry side seal I assume is good because I have no problem with idle or revving high???

why on earth does the air screw have no effect on the idle/the way it runs?
what else should I try/check???

I mean, I can seriously walk faster than this thing takes off in first gear!!!


running stock sprockets 12/49

should I skip the pilot (go back to the stock 27.5) and start messing with the needle/needle clip???

what do you all think?

I'll get another video (a better one) next time I take this damn thing out and let you all get a "good" view/listen to it......

also...as far as smoke out the exhaust running 32:1 once warmed up you can only see it smoke in the mid-range.......(and it's not alot of smoke but you can see it)

should I try a different premix ratio? I prefer running 32:1 though....I like my bearings/bottom end getting sufficient oil


Again, sorry to be a pain in the butt but this thing is driving me nuts....I've rode many 125's and I know damn well I should be able to at least spin that damn rear tire taking off in the mud...


right now I'm running...
25 pilot (stock is 27.5 but I run the 25 so the gurgle/blubber goes away)
stock needle, clip in the stock 3rd position...
stock 460 main jet....

Altitude - Elevation: here in michigan = 597 feet



am I beating a dead horse here???

 

[badseed]

one other question.....the adjustment on top of the carb that the throttle cable goes in....is that just to shorten or lengthen the cable housing? I have it adjusted all the way down so the slide in the carb bottoms out and use the idle screw to set the idle.....would adjusting that to bring the slide up/idle up a bit have anything to do with the air screw not working like it should?

I'm clueless as to what that adjustment is for....feel free to inform me what that adjustment is for

Just grasping at straws here

 

[SRAD97750]

The adjustment at the top of the carb is just for cable adjustment.
The idle speed screw sets the idle.
The idle mixture screw sets the air/fuel mixture for the pilot circuit.

At this point, I would suggest fiddling with the needle clip and see what changes for you.
FYI, it is 'tribal knowledge' that if the mixture screw doesn't affect idle, then you have the wrong pilot jet.
FYI, 'tribal knowledge' is not always correct...
-BIG DAN

 

[MikeinFresno]

the other possibility is to find someone with the same bike or carb and do a temporary swap to see if somehow the carb body has some issue like a tiny little hole somewhere that is plugged

 

[badseed]

At this point, I would suggest fiddling with the needle clip and see what changes for you.

That's what I'm going to do then.....

it is 'tribal knowledge' that if the mixture screw doesn't affect idle, then you have the wrong pilot jet

I agree, but after dropping it down to a 20 and still having no effect has me stumped I don't think going larger would help at all......

the other possibility is to find someone with the same bike or carb and do a temporary swap to see if somehow the carb body has some issue like a tiny little hole somewhere that is plugged

If all else fails I'll try and get one off ebay for $100 if I'm lucky....or craigslist.....would hate to spend that $100Plus dollars and end up with the same problem though......I'm going to mess with the needle a bit and see what I can do.....give me a couple days and I'll post an update


Thanks for the reply.....

and you would agree that bike should be able to spin the tire in the mud from take off correct? Hahaha...

 

[PawPaw]

Have you adjusted your power valves?

Paw Paw

 

[Mihylo33]

Hello again everyone....

Sorry to be a pain in the butt. However, this 2001 RM125 is driving me nuts!!!

This "bog" at take off is just driving me crazy.....(I'm ready to sell it and let someone else mess with it and just buy my son a different bike).


here's the deal....
at take off I have a awful bog....after the pilot circuit, it clears up and runs like a bat out of hell.....

Here's what I've done...
Another new plug...
(Haven't did any plug chops as it appears to be the pilot circuit I'm having problems with....but after a hour or so of riding the plug is a nice cardboard color and is NOT wet at all).
has a new air filter....
fresh gas @ 32:1
brand new clutch...
checked the timing mark on the stator (set perfect)...
rebuilt the carb (new carb kit)...and cleaned the carb I dunno 5 times now...
Float height is perfect...
This thing has the cleanest carb (inside and out) you've ever seen on a 2001.....
Did a compression test and it has 173 psi...
reeds are in excellent shape (I'm not sure but I believe they are boyesen reeds, they for sure are not stock reeds)
my air/fuel mixture screw still has zero effect on the idle?
I've dropped the pilot jet 1, 2 and 3 sizes and still no effect on the air/fuel mixture screw...

with the stock 27.5 pilot jet taking off I get a bog/gurgle/blubber....
drop it to a 25 pilot and the gurgle/blubber goes away but the bog stays...
drop the pilot to a 22.5 (same results as the 25)
drop the pilot to a 20 and it just plain runs like crap!!!
no matter what I do my air screw has no effect on the idle???

(just cruising around in any gear in the 1/8th to 1/4 throttle position the bike has a crackle/gurgle sound to it...no matter what pilot jet I'm running)

Now, if I pull the choke on while its running (engine warm) it dies....but if I pull the choke on half way and work to keep it running it appears to pull better/harder on the mid-range but the take off bog is still there/maybe even worse....

I guarantee the carb is spotless with no clogged passages....

I can't get this thing to spin the tire on take off in the damn mud.....nothing but "baaaawwwwaaaa" till after about the 1/8th to 1/4 throttle position....
I know in the mud on take off I should be able to spin that damn rear tire.....I can get them RPM's up and feather that clutch and in the mud that tire will not spin...it either bogs real bad or just plain stalls out....

what else besides a dirty carb or rich pilot jet would cause my air screw to have no effect on the idle??? (should I try riding the thing with no seat on it so it gets more air?) I dunno I'm lost.....

173 PSI on the compression test so thats telling me its not a low compression issue...
I'm not loosing any gear oil....so I assume the seal is good....
the dry side seal I assume is good because I have no problem with idle or revving high???

why on earth does the air screw have no effect on the idle/the way it runs?
what else should I try/check???

I mean, I can seriously walk faster than this thing takes off in first gear!!!


running stock sprockets 12/49

should I skip the pilot (go back to the stock 27.5) and start messing with the needle/needle clip???

what do you all think?

I'll get another video (a better one) next time I take this damn thing out and let you all get a "good" view/listen to it......

also...as far as smoke out the exhaust running 32:1 once warmed up you can only see it smoke in the mid-range.......(and it's not alot of smoke but you can see it)

should I try a different premix ratio? I prefer running 32:1 though....I like my bearings/bottom end getting sufficient oil


Again, sorry to be a pain in the butt but this thing is driving me nuts....I've rode many 125's and I know damn well I should be able to at least spin that damn rear tire taking off in the mud...


right now I'm running...
25 pilot (stock is 27.5 but I run the 25 so the gurgle/blubber goes away)
stock needle, clip in the stock 3rd position...
stock 460 main jet....

Altitude - Elevation: here in michigan = 597 feet



am I beating a dead horse here???

I think you are way lean on that pilot. Go back to a 27.5 and then up 1 to see if it makes a difference. Messing with the needle will just confuse you at this point and for the most part I've never seen anyone not use the stock needle. I think even the JD kits have a stock needle For the RMs.

 

[badseed]

Have you adjusted your power valves?

Yes, to factory settings only and it runs so much better once in the pipe....
Is it true the tighter I go on the spring = more bottom end and the looser I go on the spring = less bottom end?
I have not played with adjusting it yet...I just set it to factory settings and they are now working...before I re-set them the spring was set so tight they were stuck closed.....

I think you are way lean on that pilot. Go back to a 27.5 and then up 1 to see if it makes a difference. Messing with the needle will just confuse you at this point and for the most part I've never seen anyone not use the stock needle. I think even the JD kits have a stock needle For the RMs.

I'll give that a try before anything else and see if it helps....I did notice my manual says the bike came with extra pilot and main jets (when the bike was bought new) a extra pilot jet #30 and 3 extra main jets #430, #490 and a #520

maybe I've been going the wrong way on the pilot this whole time....

I will for sure stop and buy a #30 pilot jet tomorrow... I'm hoping to have time to mess with the bike tomorrow if all goes well.....I'll be sure to post an update with my results as soon as I get the chance to mess with the bike....


Thanks again to everyone for putting up with me and trying to help me out... I really do appreciate it!!!

 

[Nighthawk016]

where abouts are you in michigan badseed?

 

[badseed]

where abouts are you in michigan badseed?

Shelby Township....about 30 minutes North of Detroit....

 

[Nighthawk016]

well damn, if you were a lot closer id come give you a hand

 

[badseed]

well damn, if you were a lot closer id come give you a hand

I appreciate the thought Nighthawk


Quick update.....
put the stock pilot back in = runs the same.....
went one size up to a #30 = runs the same.....

Dropped the pilot back to stock(27.5) and lowered the needle clip(made it richer) from stock middle position to second from the bottom = the take off bog is 99.9% gone!!!!
However, now when riding in any gear throttle barley cracked open(just cruising along) I have a stutter/crackle to it....if I let off the throttle or give it just a bit more throttle it goes away....I read thats a sign of being rich on the pilot??? (would you say that is true or false?)

should I try leaving the needle clip where it is 2nd from the bottom (bog is gone) and drop that pilot back down to a #25 and see if that clears it up??? or put the #30 back in and see if that clears it up?

I give you carb guys lots of credit.......Taking everything I have not to throw that damn carb across the garage into the wall .....

I'm getting closer though.....The take off bog is gone


Again, everyone's help is greatly appreciated....we're getting darn close now

plug is not wet at all....and still holding that cardboard color......
(I can post a pic of the plug if you think that will help you, help me)

 

[rmboy]

Hello again everyone....

Sorry to be a pain in the butt. However, this 2001 RM125 is driving me nuts!!!

This "bog" at take off is just driving me crazy.....(I'm ready to sell it and let someone else mess with it and just buy my son a different bike).


here's the deal....
at take off I have a awful bog....after the pilot circuit, it clears up and runs like a bat out of hell.....

Here's what I've done...
Another new plug...
(Haven't did any plug chops as it appears to be the pilot circuit I'm having problems with....but after a hour or so of riding the plug is a nice cardboard color and is NOT wet at all).
has a new air filter....
fresh gas @ 32:1
brand new clutch...
checked the timing mark on the stator (set perfect)...
rebuilt the carb (new carb kit)...and cleaned the carb I dunno 5 times now...
Float height is perfect...
This thing has the cleanest carb (inside and out) you've ever seen on a 2001.....
Did a compression test and it has 173 psi...
reeds are in excellent shape (I'm not sure but I believe they are boyesen reeds, they for sure are not stock reeds)
my air/fuel mixture screw still has zero effect on the idle?
I've dropped the pilot jet 1, 2 and 3 sizes and still no effect on the air/fuel mixture screw...

with the stock 27.5 pilot jet taking off I get a bog/gurgle/blubber....
drop it to a 25 pilot and the gurgle/blubber goes away but the bog stays...
drop the pilot to a 22.5 (same results as the 25)
drop the pilot to a 20 and it just plain runs like crap!!!
no matter what I do my air screw has no effect on the idle???

(just cruising around in any gear in the 1/8th to 1/4 throttle position the bike has a crackle/gurgle sound to it...no matter what pilot jet I'm running)

Now, if I pull the choke on while its running (engine warm) it dies....but if I pull the choke on half way and work to keep it running it appears to pull better/harder on the mid-range but the take off bog is still there/maybe even worse....

I guarantee the carb is spotless with no clogged passages....

I can't get this thing to spin the tire on take off in the damn mud.....nothing but "baaaawwwwaaaa" till after about the 1/8th to 1/4 throttle position....
I know in the mud on take off I should be able to spin that damn rear tire.....I can get them RPM's up and feather that clutch and in the mud that tire will not spin...it either bogs real bad or just plain stalls out....

what else besides a dirty carb or rich pilot jet would cause my air screw to have no effect on the idle??? (should I try riding the thing with no seat on it so it gets more air?) I dunno I'm lost.....

173 PSI on the compression test so thats telling me its not a low compression issue...
I'm not loosing any gear oil....so I assume the seal is good....
the dry side seal I assume is good because I have no problem with idle or revving high???

why on earth does the air screw have no effect on the idle/the way it runs?
what else should I try/check???

I mean, I can seriously walk faster than this thing takes off in first gear!!!


running stock sprockets 12/49

should I skip the pilot (go back to the stock 27.5) and start messing with the needle/needle clip???

what do you all think?

I'll get another video (a better one) next time I take this damn thing out and let you all get a "good" view/listen to it......

also...as far as smoke out the exhaust running 32:1 once warmed up you can only see it smoke in the mid-range.......(and it's not alot of smoke but you can see it)

should I try a different premix ratio? I prefer running 32:1 though....I like my bearings/bottom end getting sufficient oil


Again, sorry to be a pain in the butt but this thing is driving me nuts....I've rode many 125's and I know damn well I should be able to at least spin that damn rear tire taking off in the mud...


right now I'm running...
25 pilot (stock is 27.5 but I run the 25 so the gurgle/blubber goes away)
stock needle, clip in the stock 3rd position...
stock 460 main jet....

Altitude - Elevation: here in michigan = 597 feet



am I beating a dead horse here???

Hello again everyone....

Sorry to be a pain in the butt. However, this 2001 RM125 is driving me nuts!!!

This "bog" at take off is just driving me crazy.....(I'm ready to sell it and let someone else mess with it and just buy my son a different bike).


here's the deal....
at take off I have a awful bog....after the pilot circuit, it clears up and runs like a bat out of hell.....

Here's what I've done...
Another new plug...
(Haven't did any plug chops as it appears to be the pilot circuit I'm having problems with....but after a hour or so of riding the plug is a nice cardboard color and is NOT wet at all).
has a new air filter....
fresh gas @ 32:1
brand new clutch...
checked the timing mark on the stator (set perfect)...
rebuilt the carb (new carb kit)...and cleaned the carb I dunno 5 times now...
Float height is perfect...
This thing has the cleanest carb (inside and out) you've ever seen on a 2001.....
Did a compression test and it has 173 psi...
reeds are in excellent shape (I'm not sure but I believe they are boyesen reeds, they for sure are not stock reeds)
my air/fuel mixture screw still has zero effect on the idle?
I've dropped the pilot jet 1, 2 and 3 sizes and still no effect on the air/fuel mixture screw...

with the stock 27.5 pilot jet taking off I get a bog/gurgle/blubber....
drop it to a 25 pilot and the gurgle/blubber goes away but the bog stays...
drop the pilot to a 22.5 (same results as the 25)
drop the pilot to a 20 and it just plain runs like crap!!!
no matter what I do my air screw has no effect on the idle???

(just cruising around in any gear in the 1/8th to 1/4 throttle position the bike has a crackle/gurgle sound to it...no matter what pilot jet I'm running)

Now, if I pull the choke on while its running (engine warm) it dies....but if I pull the choke on half way and work to keep it running it appears to pull better/harder on the mid-range but the take off bog is still there/maybe even worse....

I guarantee the carb is spotless with no clogged passages....

I can't get this thing to spin the tire on take off in the damn mud.....nothing but "baaaawwwwaaaa" till after about the 1/8th to 1/4 throttle position....
I know in the mud on take off I should be able to spin that damn rear tire.....I can get them RPM's up and feather that clutch and in the mud that tire will not spin...it either bogs real bad or just plain stalls out....

what else besides a dirty carb or rich pilot jet would cause my air screw to have no effect on the idle??? (should I try riding the thing with no seat on it so it gets more air?) I dunno I'm lost.....

173 PSI on the compression test so thats telling me its not a low compression issue...
I'm not loosing any gear oil....so I assume the seal is good....
the dry side seal I assume is good because I have no problem with idle or revving high???

why on earth does the air screw have no effect on the idle/the way it runs?
what else should I try/check???

I mean, I can seriously walk faster than this thing takes off in first gear!!!


running stock sprockets 12/49

should I skip the pilot (go back to the stock 27.5) and start messing with the needle/needle clip???

what do you all think?

I'll get another video (a better one) next time I take this damn thing out and let you all get a "good" view/listen to it......

also...as far as smoke out the exhaust running 32:1 once warmed up you can only see it smoke in the mid-range.......(and it's not alot of smoke but you can see it)

should I try a different premix ratio? I prefer running 32:1 though....I like my bearings/bottom end getting sufficient oil


Again, sorry to be a pain in the butt but this thing is driving me nuts....I've rode many 125's and I know damn well I should be able to at least spin that damn rear tire taking off in the mud...


right now I'm running...
25 pilot (stock is 27.5 but I run the 25 so the gurgle/blubber goes away)
stock needle, clip in the stock 3rd position...
stock 460 main jet....

Altitude - Elevation: here in michigan = 597 feet



am I beating a dead horse here???

Hello again everyone....

Sorry to be a pain in the butt. However, this 2001 RM125 is driving me nuts!!!

This "bog" at take off is just driving me crazy.....(I'm ready to sell it and let someone else mess with it and just buy my son a different bike).


here's the deal....
at take off I have a awful bog....after the pilot circuit, it clears up and runs like a bat out of hell.....

Here's what I've done...
Another new plug...
(Haven't did any plug chops as it appears to be the pilot circuit I'm having problems with....but after a hour or so of riding the plug is a nice cardboard color and is NOT wet at all).
has a new air filter....
fresh gas @ 32:1
brand new clutch...
checked the timing mark on the stator (set perfect)...
rebuilt the carb (new carb kit)...and cleaned the carb I dunno 5 times now...
Float height is perfect...
This thing has the cleanest carb (inside and out) you've ever seen on a 2001.....
Did a compression test and it has 173 psi...
reeds are in excellent shape (I'm not sure but I believe they are boyesen reeds, they for sure are not stock reeds)
my air/fuel mixture screw still has zero effect on the idle?
I've dropped the pilot jet 1, 2 and 3 sizes and still no effect on the air/fuel mixture screw...

with the stock 27.5 pilot jet taking off I get a bog/gurgle/blubber....
drop it to a 25 pilot and the gurgle/blubber goes away but the bog stays...
drop the pilot to a 22.5 (same results as the 25)
drop the pilot to a 20 and it just plain runs like crap!!!
no matter what I do my air screw has no effect on the idle???

(just cruising around in any gear in the 1/8th to 1/4 throttle position the bike has a crackle/gurgle sound to it...no matter what pilot jet I'm running)

Now, if I pull the choke on while its running (engine warm) it dies....but if I pull the choke on half way and work to keep it running it appears to pull better/harder on the mid-range but the take off bog is still there/maybe even worse....

I guarantee the carb is spotless with no clogged passages....

I can't get this thing to spin the tire on take off in the damn mud.....nothing but "baaaawwwwaaaa" till after about the 1/8th to 1/4 throttle position....
I know in the mud on take off I should be able to spin that damn rear tire.....I can get them RPM's up and feather that clutch and in the mud that tire will not spin...it either bogs real bad or just plain stalls out....

what else besides a dirty carb or rich pilot jet would cause my air screw to have no effect on the idle??? (should I try riding the thing with no seat on it so it gets more air?) I dunno I'm lost.....

173 PSI on the compression test so thats telling me its not a low compression issue...
I'm not loosing any gear oil....so I assume the seal is good....
the dry side seal I assume is good because I have no problem with idle or revving high???

why on earth does the air screw have no effect on the idle/the way it runs?
what else should I try/check???

I mean, I can seriously walk faster than this thing takes off in first gear!!!


running stock sprockets 12/49

should I skip the pilot (go back to the stock 27.5) and start messing with the needle/needle clip???

what do you all think?

I'll get another video (a better one) next time I take this damn thing out and let you all get a "good" view/listen to it......

also...as far as smoke out the exhaust running 32:1 once warmed up you can only see it smoke in the mid-range.......(and it's not alot of smoke but you can see it)

should I try a different premix ratio? I prefer running 32:1 though....I like my bearings/bottom end getting sufficient oil


Again, sorry to be a pain in the butt but this thing is driving me nuts....I've rode many 125's and I know damn well I should be able to at least spin that damn rear tire taking off in the mud...


right now I'm running...
25 pilot (stock is 27.5 but I run the 25 so the gurgle/blubber goes away)
stock needle, clip in the stock 3rd position...
stock 460 main jet....

Altitude - Elevation: here in michigan = 597 feet



am I beating a dead horse here???
[/QUOTE

be sure your crank seals arent leaking had an 01,03 ,04,07,84,87,95,2000...all had crank seals on both sides end up leaking...