XR250 Setup Tips

In article <27930007@hpwrce.mayfield.hp.com>, jeffmr@hpwrce.mayfield.hp.com (Jeff Merrill) writes:
|> Hi everyone out in Motoland!!!!!
|> After much deliberation and using everyones excellent advice, I am 
|> now the proud owner (along with the bank) of a '94 XR250. I just picked
|> her up last night, it's gonna be fun!!!!! I want to thank everyone
|> who responded to my last post. Without the information it would have
|> my decision even more difficult.
|> "No longer bikeless 8*) 8*)"
|> Jeff Merrill
|> Roseville Ca.
|> '94 XR250

   Good Choice. (me biased - nah!!!)...   If you have never owned an
XR before here is a ( rather long) list of hints... 

1. toss the stock front tire and go for a metzler unicross for hard 
    terrain.  I learned to ride on Beale AFB (in 1972) right near you.  Lots 
    of hardpack -> the stock tire is a 6ply irc ve-35 -> doesn't 
    hook up very well.  The stock rear tire is pretty good in everything 
    but clay mud (it packs up) and wears like iron.

2. Cutting out the backfire screen from the air filter 
    and removing the baffle in the stock
    pipe doesn't add that much noise output and really improves throttle
    response and power.  And also remember to remove the snorkel from 
    the airbox.  The only pipe worth spending any money on is a White
    Brother Mega-alloy.  If the bike is too loud with the baffle out 
    you might consider going with Thumper Racing's muffler insert.

3. Turn the decompression lever around and then cut a groove in the 
    grip so that you can pull it in with your thumb.  It's easier to 
    grab onto this way if you stall the bike coming into a corner 
    and need to bump start it, etc...

4.  If you want more stability you can drop the forks in the triple
   clamps and add a link to the chain to move the rear wheel back.

5. Change the oil and filter often, I use honda hp-4.

6. I Remove the decompression cable coming from the kickstart mechanism
   to make it start more easily.  This holds one of the valves open 
   until the kickstarter hits dead bottom.  If it gets out of adjustment
   the bike can be *very* hard to start.  With it off, it is harder to 
   kick over but I am building compression from the get-go.

7. Starting drill when cold (or after a fall).  Drain the carb with a 
   screwdriver if the  bike has been sitting a while.   Pull in the 
   decompression lever,
   and kick the bike over three to four times with the throttle held
   wide open.  (This is referred to as "clearing it out.").  Then roll
   the motor over to top dead center (i.e. roll the engine over slowly
   'til you feel resistance).  Then kick hard with no throttle.  Sometimes
   I adjust the idle up slightly during this procedure.  No choke while
   you are clearing it out and full choke when you start it cold.

8. Drill a hole in the steering stem and install a zerk fitting. Buy
   a big grease gun with high temp grease cartridge and pump the steering
   head full of grease.  Add a little grease after every wash to force the 
   moisture out.  The steering head bearings will last forever if you do
   this -> replacing steering head bearings is not fun...

9. I also drilled a hole and put a zerk in the brake pedal pivot.
     You can file off the threads that stick into the pedal pivot 
     with a round file to give a smooth surface.

10. Adjust the valves regularly.  I set them a just a *touch* on the loose
   side to give a little better bottom end torque (valve open duration
   is less).

11. Some items should only be replaced with stock honda items (which the 
     dealer doesn't usually stock -> and he will try to sell you an 
     after-market piece because he has a higher profit margin).  Definitely 
     go stock honda on :
       - levers and perches (sunlines are brittle and break easily)
       - countershaft sprockets (aftermarket ones don't fit right and 
            can prematurely wear the main shaft).
       - brake pads (a little personal preference here. The stock pads 
            work and wear very well.  I have tried both braking and EBC
            pads and they make the brakes too touchy for me).
       - oil filters.
       - shifters (I used to think the aftermarket ones were stronger 
              until I peeled one off and dnf'ed in a race - the stocker 
              will bend alot but is easily bent back which makes it  
              a little easier on the shift shaft.  And now I carry 
              a spare shifter - just paranoid I guess).

11. You can remove the "push-cable" from the throttle to get an
     easier throttle pull.   I went with a cr motion pro throttle 
     and cable which has a slightly easier and shorter pull (it is 
     only a single pull throttle).  This is available from thumper 

12.  The stock bars tend to cause alot of lower back fatigue.  I find
      and RC-III or CR-HI bend is taller and less fatigueing.  I cut
      about 3/4 of an inch off each end for weaving through the trees
      here in Oregon.  I use an answer alumi-lite cr-hi bend bar.

13. Lube the rear shock linkage with moly-60 paste -> expensive and 
    available from your honda dealer.  I have two grease guns.  One
    with high temp grease for the steering head and another with 
    a tube of moly paste for the shock linkage and swingarm bearings.

14. Remove the resistor from the spark plug cap to give a hotter spark and
    replace it with something more conductive.  Either a short piece of
    copper wire or a hunk of welding rod will do.  This will make it
    start a little more easily.

15. For carburation, I use a stock honda carburator off of a
      1985 XR350R.  It will bolt right on and the jetting is 
      almost spot on out of the box.  This works *much* better 
      than any flat slide carb sold by any of the aftermarket 
      places but the expense is great ($285.00).  If you are 
      doing alot of high speed riding a flat slide will probably
      work fine.  It adds alot to the top end but the low end suffers
      (which I didn't want).

16. I use a fourth overbore piston out of a 1985 XR250R and associated
      piston pin, rings, head gasket, etc...  This is a 76mm piston
      versus the stock 73mm.  This gives a displacement of around
      270cc.   Thumper racing sells a 77mm piston with a nascar 
      wristpin ( a requirement in my mind since the small end 
      of the rod will probably go without it).  The thumper piston
      will give you a displacement of 279cc.  If you do bore it 
      I would go with a 45 or 46 tooth rear sprocket, I run either
      depending on the terrain and tire that I am using.  With 
      the increased overall power it will very easily pull the 
      taller gearing.

17.  Be sure to set the rear shock sag at 4 inches.

18. Bleed the air out of the forks after about a half hour of riding.
     They will get harsh as the air in them expands with the increased

19. Talk to the owner of thumper racing before you buy anything from 
    anywhere else.  Nice, no bullshit kinda guy...


jeff dunham                1993 XR650L
jdunham@wv.mentorg.com     1993 XR250R
(503)685-4835              1986 XR250R