Suzuki 97 RM125, I need help please

[MrMcyummy]

Newbie here and I just purchased an 1997 RM 125 for my son and know noting about the bike or 2 strokes. Here is my issue...

At take of the bike sounds as if it were missing but picks up speed but low on torque, and does this until i get to a certain RPM, and in second if I back off it does this as well but once it feels like it hits the power band hold on cause it takes off like a rocket.

I pulled the carb and for 17 yrs old it looked amazing, (did not record the needle and Jet) and the float looked even when I turned it over, did a compression test on the cylinder and showed 125 psi, i did notice it had an NGK plug of a B7es and after looking it up on line it is a 30 dollar plug vs a 3 dollar plug thats in it now. I have ordered the new correct plug for it which is a NGK R6918B-8 but has not come in yet. The plug looked a little black but not a thick build up of oil or anything just lite carbon.

I read were it says to use only the specific NGK plug bacuase from like 1996 to 2000? i think Suzuki used a specific ignition system that uses only the Gold Irridium plug and it works the best.

I am at my wits end trouble shooting this thing could someone please shed some light on the subject please, I will take anythnig at this point. What should I look at next, the reed valve or what. I did make sure I used 32:1 ratio in the tank, as I drained all the old stuff out to eliminiate any possible over mixing issues.

Thanks,

Mike T

 

[my67xr]

welcome to Miniriders,
don't forget to drop by and say hello in our Introduce Yourself thread too.


what fuel/oil ratio was the previous owner running?

the compression sounds a bit low to me ?
when you start it up and let it warm a little, then give it a blip rev, is it hesitating at all ?

when you check the colour of the Spark plug you need to do a run at full throttle for 20 or 30 seconds in 3rd or 4th gear.
then turn it off, pull the bike up and pull the plug out there and then.
otherwise it is going to show up a dark coloured plug.
if the bike is doing a lot of idling, and just putting around it will go through a lot of spark plugs.
you should be able to get at least 5 hours out of one though,

make sure you run the Resistor style plug too, the Suzukis CDI's can play up when using a non resistor plug.
the NGK BR8EG or BR8EIX are good as they don't oil up as quick as a standard plug, and they last at least 3 times as long too.

 

[my67xr]

you might want to adjust the Idle Mixture Screw too, the small brass flat head screw on the side of the carby.
start and warm up the bike, then hold the idle speed up a little more than standard, around 1800rpm.
if you have someone do it for you it will be a bit easier, get them to hold the front brake on at the same time, this will help them keep the idle speed steady.

now slowly turn the mixture screw in or out, listening for the idle speed to increase.
you want it to run at it's highest/smoothest revs, this is pretty much spot on for the idle mixture.
once you are happy, take the bike for a run and see how it goes from there
then you can tweak the mixture screw a little if you need it.

 

[zwebx]

Yeah not really enough info... sounds like a the reeds are cracked actually..
if not bad ignition but then it wouldnt run well in band