Jump to content
Sign in to follow this  

Sx125 2002 "eats up" spark plugs!!

Recommended Posts

I need to change the spark plug very often! (3-5 rides max!).

What could be the problem?

could it be that i put a high % of oil? (2.5% /1:40)

could it be that the bike is too rich/lean?

Usuasly the bike runs great!

Please help!!!

Thanks, Eli.

Share this post


Link to post
Share on other sites

Your oil ratio is good. lots of folks run 40:1 or even 32:1 and some run 50:1, your oil ratio is not your problem. Your most likely problem is the jets themselves and the needle may need adjustment. How does the bike run when it is running? Does it run well at low throttle settings and poorer at high, or the opposite?

I would suggest you get a bottle of carb cleaner, remove the carb from the bike and give it a good cleaning, while you have the jets & needle out write down what they are and the poisition of the clip on the needle. Post back up here and you'll get some good help.

Share this post


Link to post
Share on other sites

the bike run good up and low but in 2/4-3/4 thruttle it bugs a littel (not major)

the carb setting is main - 185 pilot - 48 and needle i 3rd postion from the top.

Share this post


Link to post
Share on other sites

If it is bogging in the middle you can move the clip up so that the needle is deeper in the carb to lean it out in the middle. Try dropping the clip one position at a time and see what happens. Does the bike idle? How many turns out is your air screw.

Share this post


Link to post
Share on other sites

Yes the bike idle.

I think the problem is the the air screw is out too much.

It used to be 1.5 and I changed it to 2 out because I wanted to ride trails this one day and I didn't change it back (burned a piston once when the bike wos too lean in wide open 6th gear :-]).

If I'll go in 0.5 in the air screw it could fix it?

Thanks for the help!!

Share this post


Link to post
Share on other sites

The air screw will not affect the jetting at Wide open throttle. You need to post up what jets are in your bike. Sounds like you've got a real problem and the air screw won't fix it.

Share this post


Link to post
Share on other sites

It's just jetted too rich. Simply lean it out. Here is your chance to become a jetting guru. It's no bigger than that. You don't have to pull the entire carb to clean it. It won't hurt anything but it won't solve your problem. You may have to pull the entire carb to get at the pilot jet.

Take some time and learn the different circuits, 1)pilot, 2)needle, 3)main, and what they do. How to replace them..............Then you simply need to experiment. :ride:

Take a day & just trail & error. Methodically, one step at a time. Note where you are right now and you simply need to lean it out. You've identified where it runs poor, now which circuit effects that area.

There is NO SUBSTITUTE for hands on experience. :worthy:

Good Luck! 👍

Hint: tkinney80 has given you some good advice! I'm sorry, I will not give you the easy fix. Teach a man how to fish....................... etc.

Share this post


Link to post
Share on other sites

Check you reeds and possibly your crank seals. If the bike used to run good with the jetting you have then something has changed. Obviously, cleaning the carb never hurts, but if the bike ran fine for 10 years and is now having problems something is wrong.

Share this post


Link to post
Share on other sites

More than likely it needs a top end job at teh very least. Probly a cylinder replate as well.... Worn out rings/cyinder will cause a bike to run rich and foul plugs..

Share this post


Link to post
Share on other sites

From the sounds of it you just need to lean out your needle. Helped my exc300 a lot.

Share this post


Link to post
Share on other sites

:worthy: These guys are just messin' with you!

Don't forget to tell him 'bout that pesky piston return spring. :ride:

KJ55 & tkinney80 have it right, but you should learn the whole jetting thing. Not just the quick fix. Oh well, that's just me. 👍

P.S. I had a 300 that was so sensitive to jetting, it changed when I climbed a hill or the weather changed from morning to afternoon.

Share this post


Link to post
Share on other sites

So you guys don't think that a 10 year old cyinder might be worn out? Or the rings are shot?

Share this post


Link to post
Share on other sites

or float level is too high...

old bikes bring many problems along with them, especially if it is fairly new to you.

Share this post


Link to post
Share on other sites

All those things are definitely true. The OP did say he burned a hole in the piston, did you rebuild it, or have a mechanic rebuild it and take a look at the lower end?

Share this post


Link to post
Share on other sites

what does "eats up" mean

is the electrode wearing out? Or is it black/fouled ?

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...