Running To Rich

[railrider]

Hey guys just getting into off road and I have a 2005 yz250 2 stroke. the bike was bought brand new and i have about 10 hours on it, granted i'm not constantly running wide open but im getting on it, but i keep going thru spark plugs. i was running the yamaha r2 oil with a 32:1 ratio and was running to rich, ii was then told to try running the synthetic amsoil at 50:1, and i'm still going thru plugs. when i say going thru plugs if im out for a 12 hour day at the track i'll go thru 3 plugs. what im wondering is what othe adjustments can i make so i dont go thru as many plugs.

should i ....drop the needle
.....air gas mixture
i'm at a loss anyone with any suggestions would be appreciated


railrider, fuquay-varina NC

 

[railrider]

what happens is i'm getting great power, but then all of a sudden it "bogs down" and stops running, and wont start back up. when i take out the plug it has oil on it and carbon build up. I replace the plug and it runs great again for a little while and then the same thing happens

 

[railrider]

i was told that from the factory the bike will run to rich and i should drop the needle, what do you think

 

[railrider]

thats just what i have been told...ok i'll go it from there!! thanks

 

[Rooster]

Hooo boy. YZ. What can I say. They come out of the box jetted insane.

Read your manual. If you bought it brand new, you have one, if not, go buy one, NOW!! Go to your local shop, and buy smaller pilot and main jets. Get one or two sizes smaller. Go one step at a time, starting with the pilot and drop the needle one notch at a time. Last thing you want to do is go too far and burn up your bike.

Another thing - if you are running the "recommended" spark plugs in your YZ, throw them out and go with a BR8ES or hotter.

I've been through this on both of my YZ's, it takes a little time and patience, but once you get her spot on, you will love it.

 

[railrider]

thanks for the input, but heres a dummy qusetion, what are the stock jet & pilot sizes , and what should i go down too, main jet start at notch #1-5????

 

[railrider]

ooppps or just start by lowering the needle 1 more notch from where it is now

 

[Rooster]

Read your manual. Read your manual, save yourself from the frustrations. It's all in there, step by step. There is a list that tells you what the stock jetting is on your year/model. I have a '00 YZ250 and pretty much any question I have is answered by reading the manual, aside from how to be a better rider ;)

Drop your needle a clip, and throw one size smaller pilot jet in there. You may have to lean out your main jet too, it takes time, be patient. Make sure you go to the standard spark plugs as I mentioned before. The elecrode on those high dollar plugs foul up in a hurry.

My best bet is you are fouling plugs because you aren't keeping up in the RPM's. I used to get that all the time, because I trail ride my YZ. Once I dropped the needle and played around with the jets, all became well.

Best of luck

Roost

 

[railrider]

ok going to do what you suggest and yes i'm not always keeping the rpms screaming. And the plug i'm runnging is the br8eg....is there a difference between that and the br8es...thats the only question i have left and it's off to wrenching!!!

thanks for the help
railrider

 

[Rooster]

The BR8EG has the fine electrode, it's a racing plug, which allows for a quicker "spooge" foul. The BR8ES is a larger electrode and will run longer. Plugs will not make things that much better, re-jetting the carb is your best bet.

http://www.ngk.com/results_cross.asp?pid=BR8ES

http://www.ngk.com/results_cross.asp?pid=BR8EG

Oh yeah, and by the way RedRyder - I aint no "Mr." I may be old, but I'm way too unrefined to be called Mister! ;)

 

[Rooster]

Just bustin' your chops :boss:

 

[railrider]

yeah like i said droped the needle tonight and will go from there, i learned a long time ago small changes so you can trck the differences incase you run into a problem, i was just wondering about the plugs......mainly because one is $2.00 the other is $4.75 and when you have been going thru plugs like i have 4.75 adds up to alot!!! i let you know how it runs with all the adjustments..thanks again

railrider

 

[Rooster]

Good plan. I dropped my needle one notch, and went one step leaner on the pilot and the main, and all seems well. It still runs a little rich, but I tend to err on the cautious side on that. The last thing I want to do is burn up my cylinder when I'm miles away from the staging area. I still carry a spare plug in my camelbak, just in case :think:

 

[I<3Dirt]

Sorry to come into someone elses thread and ask a a question but..I'm having the same problem and just want to confirm what you mean by "dropping the needle". Do you mean moving the clip itselft, up one position so that the needle sticks out farther, or moving down one?

 

[I<3Dirt]

We were saying to move the clip up one notch so the needle is further down.

Okay, thats what I was thinking, but just wanted to make sure.
Thanks.