2007 rm125 bog

M

murph243

1422920674404.jpg 1422920750643.jpg
Hey guys, so I have a 2007 rm125 that I was told was bored to a 144. It bogs very bad until about mid throttle, I just rebuild the carb using smaller jet sizes and I hope this will help. I then started doing some research on the reeds and how that can affect this. I'm very new to two strokes so I don't really know what I'm working with. The reeds seem to be in decent shape to me, how do I even adjust these? Any other suggestions on how to get this thing running like a real bike? Thank you guys I appreciate it!
 
SRAD97750

SRAD97750

Moderator
Staff member
WELCOME! And say Hi to the toe you're waving at us! :smirk:

Those reeds look to be in great shape.

You mention bog off throttle. Is it a complete bog or more of a burble when you open the throttle?
Does it clean up at a particular throttle position?
-BIG DAN:thumb:
 
M

murph243

Hi big dan it is complete bog that clears up somewhere right before mid throttle. It is in all gears at the low end. I just rebuilt the carb yesterday and don't have it back in yet, I'm totally unprepared right now so I apologize but I know one of the jets was a 42.5 and we put in a 40 (what the kit came with) I don't remember the other size but I know it changed. I also have a few jets in my shopping cart waiting to be purchased. I'm seeing 380 32.5 alot what do you guys think about that? As for the head I can't say the guy I bought it from swears it is fresh but I don't know how much I can trust that. I feel like you have to get 40 million things right to get this thing running right, I may be way over my head lol
 
P

PawPaw

If the power valves are not correct it will make you have a bog. But, remember that all 125's are a bit sluggish at lower rpms as they need to scream to make good power.
What does you spark plug look like? White, Black, Grey?
Have you done a compression test?
Have you checked the carb float level setting?

PAw Paw
 
M

murph243

Hey pawpaw I realize some sluggishness but this is far worse than that, how do I check and or adjust my power valve? And that's the reeds right? I pulled the spark plug today and it is black, it's not super gunky but is black. Thanks you
 
P

PawPaw

OK, the power valves are not the same thing as the reed valves. The power valve is an adjustable set of valves that alter the exhaust opening and thus port timing. If they are sticking due to dirt or sludge build up it will have a great effect on the power delivery.
The black plug tells me you are either running rich, have low compression, a carb float valve set too high, a leaking float valve or possible a leaking crank seal on the clutch side.
You really need to pick up a service manual for your bike as it will help with all of these possibilities.
Go here and look under the engine tab at the exhaust valves.
http://www.bikebandit.com/oem-parts/2007-suzuki-rm125/o/m10394#sch528107

Do the other checks I have previously mentioned to get to rout cause of your problem.

Paw Paw
 
Last edited:
M

murph243

Hey guys I wanted to let you know I put the carb back in freshly rebuilt ran 32:1 and about 90% of the hesitation and bog was gone! I was thinking about selling it before I rode it today and now I'm going to keep it because it's a little ripper! My next project is going to be redoing the forks and shock ad they are in pretty sad shape, can I ask you guys your recommendation on suspension settings? I weigh 200 lbs without gear am an intermediate rider and will only be riding tracks. It's mostly sand and clay down here. What are your recommendations for fork/shock spring rates and oil levels? Thanks guys
 
M

murph243

Hey guys I'm about to change the trany oil what are your recommendations. I've seen people argue for both oil and trany fluid. If it has oil in it now can I put trany fluid in there or would I have to flush it? Thanks guys
 
SRAD97750

SRAD97750

Moderator
Staff member
murph243:
Hey guys I'm about to change the trany oil what are your recommendations. I've seen people argue for both oil and trany fluid. If it has oil in it now can I put trany fluid in there or would I have to flush it? Thanks guys
Click to expand...
I would flush between changing types of fluid.
If you are switching to ATF, flush with ATF.
If it's already motor oil, you can add motor oil without flushing. -BIG DAN:thumb:
 
O

ossagp

If you want to try atf you can just change it out, without flushing it though you won't have a true idea of what it is going to be like since you could retain 10-20% of what was already there. I little tip on nomenclature, both atf and any other liquid lubricant can be properly termed "oil". probably anything you can buy came out of the ground as "oil", or was created from pulverized seeds as "oil".

How are your plugs coming out now?
 
Top