Jump to content
Sign in to follow this  

Suzuki Rm125 Bog

Recommended Posts

hi i have a 1998 Suzuki Rm125 2Stroke, with FMF gold series fatty and power core2 shorty on the back, i have Boyesen power reeds installed, with 168 main jet and 50 pilot jet, it bogs a little bit when letting off to go around the corner and when you get on it after coming out of the corner it bogs a little bit and then it starts to go, so i was wondering if i should go down to a 165 main jet? and what position would the needle clip need to be in?, i know for sure the pilot is right, and how many turns out from all the way in should the air screw be out? and the spark plug is almost a coffee brown colour, still a little black yet, (still rich) and for my gas i run 19 litres of fuel : 13oz of Amsoil dominator series synthetic 2 stroke oil.

 

Any suggestions on what do to do to get the bog out would be perfect and very helpful,

 

Thanks, DirtbikeRiderRaes02

image (8).jpeg

Share this post


Link to post
Share on other sites

Considering your engine is mechanicaly sound: fresh top end, reeds, clean air filter, good crank seals, silencer packing,

 

the cool fall weather has leaned out your jetting, going to a leaner 165 main jet will make it worse.

If you don't know the air screw's baseline setting, you cannot be sure the pilot jet is the right size.

 

At a minimum run the needle clip in the middle position, raise or lower the clip's position to adjust

the 1/8 to 1/4 throttle response: bog means too lean, stuttering / cutting out means it's too rich.

raising the clip = leaner, lowering the clip = richer

 

Take the time to read thru this recent thread:

http://www.thumpertalk.com/topic/1157132-jetting-question/

 

If you mostly trailride (even some recreational MX'ing)

Amsoil Dominator isn't the ideal choice as it has a higher flash point / works better in higher temps,

perhaps consider using Interceptor as it will be less prone to spooging & fouling at low speeds / cooler temps.

 

13 US oz of oil (about 385ml) to 19 litres of gas is roughly a 50:1 premix ratio,

hopefully you mostly trailride your 125 and not run it wide open for too long.

Edited by mlatour

Share this post


Link to post
Share on other sites

In that case I'd look up the original settings for that model/year and start from there.

The only way it will be tuned 'perfectly' is if you tune it in the actual temperatures it will be raced in.

Every 10°Celcius rise/drop in ambiant temperature requires a jet change or setting adjustment if you want a spot-on perfectly tuned 2T race engine.

Edited by mlatour

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...