help at the sand dunes

[jeremym1234]

I'm heading to the sand dunes in a couple of weeks, and I had some problems last year I want to avoid this time around. Here are a couple of "newbie" questions:

1 - Last year at the sand dunes (St Anthony, ID) my bike fouled 4 or 5 plugs. It never does this at home (Boise). I've never played with my jetting before, but have a feeling I'd better be prepared to do so this time around. I believe I'm heading UP in elevation, although I haven't checked the map yet. I ride a '96 YZ250. Any advice?

2 - I'm going to buy a paddle tire this year. It will only be used once or twice a year. How many paddles is considered "standard"? I'm guessing the number of paddles depends on the type of sand you will be running on?

thanks in advance,
J.D.

 

[skhasky]

Can't help you with the paddle - can help you with the jetting. If you are fouling plugs - you are probably running rich. How rich? Well... how does it run in Boise?? You will need to find out the difference in elevation. Normally, when you run in sand you want to be jetted a little rich - keeps things cooler. Sooo... if you are running right in Boise and only traveling up a few hundred feet - it should be ok. But it's not! So... how to fix it. I'd say take along a step leaner pilot jet, and a couple leaner mains. Run a fresh plug and run it WOT. Hit the kill switch and let it stop. When cooled a bit pul the spark plug and check it. If it is black, go down 1 size on the main and try again. Once you get it to run clean on top, turn your attention to the needle. Try rolling on the throttle from 1/4 to 3/4. Does it spit and burble? If so - put the clip in a higher groove (drop the needle). If it goes 'buwahh' and hesitates and/or surges then raise the needle (put the clip in a lower groove). Now to the pilot/ Air screw! This is an easy one... try riding around in 2nd gear - 3000RPM (low RPM) - does it cruise along sounding like a bumblebee? When you hit the gas does it wheelie? If so, the pilot circuit is good! If, however it sounds like you are making popcorn in your exhaust pipe, you are too rich. You need to turn the airscrew out 1/4 turn and try again. If you get to 3 turns out and it is still rich, use the smaller pilot, set the airscrew at 1 1/2 turns out and try again. You know you went to far (too lean) when the bike goes 'Buwaaahh' - bogging before taking off (also called sucking hard). Also, it will 'hang' at high idle for a second when you blop the throttle in neutral. Practice removing your main/needle/pilot at home and record which tools you had to use. Take your jets and a couple of spark plugs with you. When at the dunes, it shouldn't take more than 1 hour tops to get the jetting set. From there, enjoy the fun!
P.S. A couple of things about sand dunes.... Make absolutely positive your airfilter is clean,oiled, and seals tight. Any sand and your engine is toast. Lube your bearings and linkage before you go. Sand dunes are notorious for demolishing bearings. Let the bike cool from time to time. San is really hard on the motor. It will tend to run hot, so don't get it to the point that the coolant is boiling. Have fun!

 

[jmics19067]

does it cruise along sounding like a bumblebee? When you hit the gas does it wheelie? If so, the pilot circuit is good! If, however it sounds like you are making popcorn in your exhaust pipe, you are too rich

I like that dang so easy yet so true but what woudl it be if mysounds like my bumblebee is stealing my popcorn :confused: ;)

 

[skhasky]

A few squirts of RAID in the intake tract does wonders , so does a little honey in the gas tank... :)

 

[BigBore]

An 8-paddle is all you need on a 250.

 

[jeremym1234]

Great. Thanks for the help guys.