RM125 2003 suzuki rm 125 full rebuild,

[danielzak1990]

Hey guys, i just wanted to share my expierence with rebuilding my
2003 suzuki rm 125
I bought the bike mid season last year, ive been riding motocycles for a while now hut never owner a motocross,
Anyways, i rode the bike for the rest of the season , everything seemed fine, just small things, like forks leaking a bit i knew it would have to be done soon, also i was planing to do my top end because the compression was getting low , but this was my expiernce , im a rookie and i had nothing else to compare my bike to, when i started taking things apart i wanted to clean the bike as well, as things were comming off more things i found that were worn out or broken completly.
My forks had 100 ml oil in each fork
My piston had a huge mark in it
My linkage was impossible to move lol
It was bone dry.
My rear shock had no oil and nitrogen in it
My throttle cable was barly holding on,
The power valve was wasnt opening fully it would stick.
Just speaking from
My expiernce i strongly recommend for everyone to do this to their bike, because after i rode it when it was done, it was like day and night , what a difference
Heres some pics of my build




Thats my piston


Here it is all stripped


And there she is all back together,
She cleaned up nice

 

[danielzak1990]

My pipe was very rusty, I thought i needed to buy a new one, but some guys in my previous thread gave me the idea to paint it with high heat bbq paint.
I sanded it with a wire brush and painted it, looks amazing
Thanks for the idea

 

[SRAD97750]

AWESOME
I love it. I am in the middle of such a build. It is good to hear that it will all be worth it in the end.
THANKS!!! -BIG DAN

 

[bobkyle2]

Niceeee ... My buddy has a 03RM125, We will be doing a full rebuild over the winter, With a big bore kit more than likely.

PS, I hate the powervalve setup on those 03's

 

[jackson409]

Nice, I have done mine too, only one pieace a time I have that same seat cover on mine

 

[danielzak1990]

Niceeee ... My buddy has a 03RM125, We will be doing a full rebuild over the winter, With a big bore kit more than likely.

PS, I hate the powervalve setup on those 03's

Nice, i was thinking about the big bore kit, but i dont use all the power on it the way it is now, especially now that the power valve works properly,
So im gonna wait and get better at ridding.
The biggest improvement on the bike, is working suspension, its properly set for my weight , like what a difference, i had nothing to compare it to before..
But now i love it.. The bike is so smooth when going thru the whoops

Im gonna strip it down every winter

 

[mylilpony]

How can u tell when the powervalve sticks? & how did u free it up?

 

[SRAD97750]

How can u tell when the powervalve sticks? & how did u free it up?

Open the covers and spray the assembly out with carb cleaner and work the valve back and forth. Might require removal of the PV and a more thorough cleaning. -BIG DAN

 

[danielzak1990]

How can u tell when the powervalve sticks? & how did u free it up?

Powervalve is supposed to move freely, mine used to get gunked up all the time when i use to mix 32:1 ratio.
Now i run 50:1 and i never had that issue again, the ore mix oils we have now days dont require being mixed at 32:1 , those specs were for the old mineral oils.
I use amsoil 'interceptor' at 50:1 and no more power valve issues.

To clean the power valve 'brake cleaner' works great.
You can try removing the covers both the side and front and try to clean it that way. In my case i had to take it apart and clean it pieace by pieace, i probably spent 3-4 hours on power valve alone. Its worth it in the end

 

[Mihylo33]

Powervalve is supposed to move freely, mine used to get gunked up all the time when i use to mix 32:1 ratio.
Now i run 50:1 and i never had that issue again, the ore mix oils we have now days dont require being mixed at 32:1 , those specs were for the old mineral oils.
I use amsoil 'interceptor' at 50:1 and no more power valve issues.

That's bad info right there. They'll even tell you right on the bottle to follow the engine manufacturers mix specs.
Mix ratios can vary depending on the rider, the climate and the type of riding one does. A MX guy like myself will run 30:1 and in the small bore bikes like 125's and 85's I will run 24:1.
Now someone that runs tight single track in the trees that doesn't see any wide open throttle may run 40:1 or even 50:1 with the proper jetting. Newer KTM MX bikes are currently running 40:1 because of better tolerances, higher quality materials and proven performance testing and jetting.

 

[2smoke]

ALL WAYS ALL WAYS ALL WAYS, run the manufactures pre mix ratio. Jet your carb correctly for your elevation and day time temperatures and adjust your air screw accordingly. Im not an MX guy. Im a casual trail rider and desert racer (Im slow Ask Travace he has ridden with me). But Ive never deviated from what the pre mix ratio is supposed to be and have never had gummed up power valve issues from over oiling in the pre mix. The oil is supposed to be there in that quantity. Its engineered. So unless your an engine engineer and know more than the manufacture engineers. I recommend you follow what the manual states.

 

[danielzak1990]

ALL WAYS ALL WAYS ALL WAYS, run the manufactures pre mix ratio. Jet your carb correctly for your elevation and day time temperatures and adjust your air screw accordingly. Im not an MX guy. Im a casual trail rider and desert racer (Im slow Ask Travace he has ridden with me). But Ive never deviated from what the pre mix ratio is supposed to be and have never had gummed up power valve issues from over oiling in the pre mix. The oil is supposed to be there in that quantity. Its engineered. So unless your an engine engineer and know more than the manufacture engineers. I recommend you follow what the manual states.

Ive had my carb jetted by a guy thats over 50 years old and never rode anything else but rm125 ever since 1980's , my carb is jetted properly , ive done several plug chops and the plug comes out perfect 'coffee with milk' colour, the bike is very responsive and runs amazing. I used amsoil interceptor and when i mix 32:1 , the packing in my silencer got soaked after a few hours of ridding, after several hours the bike would get louder and eventually start spitting out oil out of the exhaust. So i ended up replacing the packing and cleaned out the pipe and started mixing 50:1 , and never had an issue with any of that again. I checked my top end every 5 hours of run time and everything seems perfect, the bearings are lubed and no wear on the cylinder, the bike is more responive and theres still smoke comming out the back.

Keep one thing in mind when that engine was designed, we didnt have the oils we have now days, everyone used mineral oils that werent nowhere near as good as the oils we have today.
But in the end its ur decision, i run 50:1 and im very happy. I replace my top end every season it only costs $150 in parts and takes about 2-3 hours to do. I do about 20-30 hours of hard ridding on a piston.

 

[Mihylo33]

 

[SRAD97750]

Ive had my carb jetted by a guy ... my carb is jetted properly...

...when i mix 32:1 ... the bike would get louder and eventually start spitting out oil out of the exhaust...
...started mixing 50:1, and never had an issue with any of that again.

I'm sure you are aware that altering premix ratios requires rejetting. Otherwise, it wasn't correct to begin with. -BIG DAN

 

[SRAD97750]

I am excited about this build! Keep the pics coming!!!
Got any video riding this thing? Looks Awesome.-BIG DAN