RM125 oil spiiting out muffler

[Braden Colter]

Just got a nice 2003 rm125 starts first or second kick, when I ride it, it spits black oil out the muffler. I run 32-1. Would u suggest a new muffler or does it need re jetted? I know the guy before me ran 40-1 and it still spitted a little oil out the muffler. Also to add what is a good indicator that your bike needs rebuilt? 

[ohiodrz400sm]

 

 

 

Just got a nice 2003 rm125 starts first or second kick, when I ride it, it spits black oil out the muffler. I run 32-1. Would u suggest a new muffler or does it need re jetted? I know the guy before me ran 40-1 and it still spitted a little oil out the muffler. Also to add what is a good indicator that your bike needs rebuilt? 

 

The fiber glass packing inside the muffler likely needs replaced. It becomes saturated over time. It's basic 2 stroke maintenance.

 

A compression test will give you some insight into top end condition.

 

[KnotAPro]

On ‎8‎/‎25‎/‎2019 at 8:05 PM, Braden Colter said:

Just got a nice 2003 rm125 starts first or second kick, when I ride it, it spits black oil out the muffler. I run 32-1. Would u suggest a new muffler or does it need re jetted? I know the guy before me ran 40-1 and it still spitted a little oil out the muffler. Also to add what is a good indicator that your bike needs rebuilt? 

NOTE: Please! excuse any spelling and grammar mistakes.

I would go with ohiodrz400sm suggestion of repacking the muffler. There are videos up the wazzu on You-Tube for that. Also there is a IOWA Tech School instructor who posted several videos on 2-stroke rebuilds. I have a 2002 RM125 that I rebuilt following the OEM Service Manual, but I am also a Trade School educated Motorcycle Technician "OLD School" though. If you are mechanically inclined then take that engine out of the bike and rebuild the engine. Then you will know what is in the engine and no guess work for if the previous owner did anything even if they tell you it just was rebuild at a shop and shows you the paperwork. The only difference in your 2003 through 2007 model RM125's engine and my 2002 RM125 is with the components of the Power Valve and maybe the Reed Cage. I strongly suggest refurbishing/replacing the Steering Stem, Wheel(s), Swingarm, Linkage Bearings while you have your engine out of the frame. I would advise you to replace your front and rear brake pads, flush the brake fluid systems while you're at it too. Do your throttle and clutch cable maintenance. Then you will know what you have with those components too. Buy either front and rear inner tubes as spares or buy a spare set of wheels and refurbish them to have a complete second set. Then you don't have to change an inner tube but just slap the other wheel on. I don't know if you ride at a track or race it too. But for me on Raceday or travelling 25 plus miles away from my house "I always carry a 2nd set of wheels". On raceday no matter what I have my 2nd set with me. Replace your air-filter today, clean the old one as a spare, even if the previous owner just did, again then you know what you have in your bike. Buy a spare set of Clutch and Throttle Cables, second set of Clutch and Break Levers. I've seen too many riders fall and break their clutch lever "end of day" result. You can break your front brake lever and still ride that day but having a spare set of both makes for being a prepped type of person.

I know this is a long list of expenses and maintenance items but being prepared for a day at the track, riding in the woods and especially a Raceday makes a ton of difference in all the other people who show up to ride/race then crash or breakdown and then they have to borrow your stuff to get a full day in. I am an older guy who started really late in life riding dirt bikes. I am now 61 years old and I am well know for being prepared for all the stuff I've described to you. I even have a spare chain in my stash of items to be ready for what might cause an unexpected issue on any given day. But that's me and I've seen too many dads/moms not being prepared for when their child is not able to race the rest of the day after a practice crash. My last suggestion is buy a spare kick start lever and bolt, ya never know when that will snap or that bolt will vibrate loose.    

[Braden Colter]

On ‎8‎/‎26‎/‎2019 at 10:11 AM, ohiodrz400sm said:

 

 

 

 

 

The fiber glass packing inside the muffler likely needs replaced. It becomes saturated over time. It's basic 2 stroke maintenance.

 

A compression test will give you some insight into top end condition.

 

Okay thanks