Jump to content
Sign in to follow this  

125 jetting Where to start?

Recommended Posts

I picked up an 03 yz125 that has the athena cylinder kit. I replaced the water pump seals when i got it as they were leaking and since then the bikes been running great. My question if about jetting, I believe my bike is running rich. I have already put about 4 pretty hard hours on it and it has never fouled out or had any hesitations or misses. But Ive checked the plug and it is very oily and black, even so much as to leave oil around the spark plug hole when i pull the plug. It also seems to smoke a decent amount even when fully warmed up. Where should i start with jetting. I tried playing with the mixture screw with the idle all the way down and It didn't seem to make much difference. Where should I start? (No idea what jets are currently in it)

Thanks

Share this post


Link to post
Share on other sites

well see what jets are in it. Clean the carb, make sure the float height is in the ball [ark (can mess jetting up) so if its out of spec, could be the problem. Check the reeds. Let us know if everyting checks up ok, then you can start from there. Is their a lot of spooge?

Share this post


Link to post
Share on other sites

Ya that sounds like a good place to start. Spooge is there but I dont think its really that bad. Tiny bit out of the end of the pipe and the PV breather hose. I am missing the exhaust header springs so there isnt a great seal there if that would affect anything. I have those on order

Share this post


Link to post
Share on other sites
I picked up an 03 yz125 that has the athena cylinder kit. I replaced the water pump seals when i got it as they were leaking and since then the bikes been running great. My question if about jetting, I believe my bike is running rich. I have already put about 4 pretty hard hours on it and it has never fouled out or had any hesitations or misses. But Ive checked the plug and it is very oily and black, even so much as to leave oil around the spark plug hole when i pull the plug. It also seems to smoke a decent amount even when fully warmed up. Where should i start with jetting. I tried playing with the mixture screw with the idle all the way down and It didn't seem to make much difference. Where should I start? (No idea what jets are currently in it)

Thanks

one thing worth checking before jetting is the right hand crank seal. the bike may run okish but it will drink your transmission oil, just attach a clear tube to your gearbox breather. dip the end in oil and see if is sucks oil in. it shouldnt. a 2t will never run properly with a leaky crank seal. i had a lc 350 do that.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×
×
  • Create New...