Adjusting valves

Virago 250 valve adjustment

XV250 engine – Valve Adjustment (click to enlarge)

XV250 engine – Valve Adjustment (click to enlarge)

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If you want to print the above picture, this black and white version will use less ink:

XV250 Valve Adj (Click to enlarge)

XV250 Valve Adj (Click to enlarge)

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Preparation (Steps 1 and 2)

Step 1)
Get these together a few days before you are going to do the valve adjustment
a) 24mm wrench for the valve cover access plugs – a 15/16 wrench will work but fits very tight.
b) feeler gauge
c) two large washers that are used as a screwdriver to unscrew the two access plugs on the left side cover. Do not use a large screwdriver.
1) For the small timing mark cover (the upper cover) – washer .060 thick x 1.25 to 1.5 inch diameter
2) For the crankshaft cover (the lower cover) – washer .090 thick x 1” to 2″ diameter.

Step 2)
It might be a good idea to try to loosen the timing mark cover (the upper cover) before the day you intend to do the valve adjustment.  Mine was very tight and I wasted a lot of time trying to remove it.
1) Use a washer (.060 thick x 1.25 to 1.5 inch diameter) as a screwdriver to remove the timing mark cover.
2) Tap the washer lightly with a hammer to make sure it is seated in the slot
3) Grip the washer with vise grips
4) Loosen the access plug, then re-tighten it snugly – not too tight.  Now it will be easier to remove on the day that you do the valve adjustment.

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Step 3)
Remove the seat

Do Step 4A   OR   Step 4B

Step 4A) To remove the gas tank
Make sure that the fuel petcock is “ON” or “RES”  (not “Prime”).
You do not need to drain the tank.
Remove the two 8 mm head bolts on each side – the left side holds the petcock and the right side holds the fuel pump to the tank.
Remove the rear bolt that holds the tank to the frame.
Remove the tank (the petcock is still attached and all hoses are in place.)
(As long as the fuel petcock is “ON” or “RES”, you should not spill much or any fuel.)

Step 4B) To raise the gas tank up a few inches (without removing the tank)
Make sure that the fuel petcock is “ON” or “RES”  (not “Prime”).
You do not need to drain the tank.
Remove the rear bolt that holds the tank to the frame.
Raise the tank up a few inches and hold it in place with some towels (the petcock is still attached and all hoses are in place.)

(As long as the fuel petcock is “ON” or “RES”, you should not spill much or any fuel.)

Step 5)
Before removing the tappet access plugs, carefully clean the area around them. Same for the spark plugs – clean around them before removing.  A toothbrush and compressed air work well for this.

Step 6)
Remove the tappet access plugs – you need a 24mm wrench – a 15/16 wrench will work but fits very tight.

Step 7)
Remove the spark plugs – you need a 14mm spark plug socket

Step 8)
Remove the small timing mark cover (the upper cover) – using a washer .060 thick x 1.25 to 1.5 inch diameter

Step 9)
Remove the crankshaft cover (the lower cover) – using a washer .090 thick x 1” to 2″ diameter.  This cover is plastic and is easy to remove.

Step 10)
Using a 17mm socket, rotate the crankshaft counter-clockwise.
Stop when the pointer lines up to the  ” │├ ”    mark .  This is Top Dead Center for the front cylinder.  Try to move the valves by hand side-to-side in the front cylinder.  If they are tight, you need rotate the crankshaft counter-clockwise a full turn – stop when the pointer lines up with the same mark as before.  Now the valves in the front cylinder will have some play.  Use a feeler gauge to measure the play in the valves.  Intake valve gap should be .10mm.  Exhaust valve gap should be .12mm

Step 11)
If the valve needs adjustment, loosen the locknut (8mm wrench), and then turn the adjuster (3mm wrench). A small movement (approx. 1/8 turn) is usually all you need.  Then tighten the locknut and measure the play again.  If it is not in spec, adjust the valve again.  After you tighten the locknut, always measure the play again.

Step 12)
Repeat steps 9 and 10 for the rear cylinder. Using a 17mm socket, rotate the crankshaft counter-clockwise.
Stop when the pointer lines up to the  ” ”    mark . This is Top Dead Center for the rear cylinder.

Step 13)
When complete, put everything back together.
Before re-installing the spark plugs, apply anti-seize to the spark plug threads.
Torque the spark plugs to 8.4 ft lbs.
Carefully check the rubber o-rings on these:
a) tappet covers
b) timing mark plug
c) crankshaft cover

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Virago 250  – adjust valves every 3,000 miles – engine must be cold
intake  .10mm  (range .08mm to .12mm)
exhaust  .12mm   (range .10mm to .14mm)

– intake  .004 inches  (range .003 to .005 inches)
– exhaust  .005 inches  (range .004 to .006 inches)

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For a little more performance and gas mileage – set valve clearance to a little over maximum.
– intake  .13mm or .14mm
– exhaust  .15mm or .16mm

– intake  .006 inches
– exhaust  .007 inches
I use this setting for my bike, and it did not increase the amount of valve clatter noise.

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9 Responses to Adjusting valves

  1. ted pellerin says:

    How long does the job take typically?

    Ted

    • lstrick115 says:

      Hi Ted,
      The prep work (steps 1 and 2) takes one or two hours.
      Make sure you do the prep work several days before you do the valve adjustment.
      The actual valve adjustment (steps 3 to 13) takes two to four hours.
      Some people can do it faster, some slower. For a person doing a valve adjustment for the first time, I would just figure half a day.
      Hope this helps.
      -Les S.

  2. ron says:

    very nice instructions are the clearance the same for a 2015 xv250

    • lstrick115 says:

      Hi Ron, The Virago 250 has had very few changes for 20 years, but I did not know for sure if the valve clearance was the same.
      I got this info from the Virago Tech website:
      Virago 250 valve clearance is .08~.12mm intake and .10~.14mm exhaust from a 1994 manual repair.
      A Yamaha service department has verified that the valve clearance of a 2014 Virago 250 is the same as a 1994.

  3. Randy Waters. says:

    Have any of you owners considered a cam change? Maybe .020″ more lift & possibly a duration increase of some degrees? Maybe CRANE or another co. could regrind a stock cam…also, is there a drag bike class for 250cc engines? New to this site, non-owner, but still considering after 1 yr.

    • lstrick115 says:

      Hi Randy,
      If you go on the Virago Tech website, there are a few people there that have put in a hotter cam and post their 1/4 mile ET.
      For me, I would not change the cam – because the Virago 250’s good mid-range torque is part of what makes the bike so great. To me, the Virago 250 seems faster than it really is because of the good mid-range torque and because the engine is so responsive.
      -Les S.

  4. Marko says:

    Hi Randy,

    So if I am not mistaken, iyou set the valves :
    – intake .13mm or .14mm
    – exhaust .15mm or .16mm

    So there is absolutley no noise, no rattling and I will get better performance of the bike ?
    How much performance and did you had any issues since your last adjustment ?
    And how on earth you found out that ?

    • lstrick115 says:

      Hi Marko,
      I read it on a forum years ago- probably the XS650 or Hypermilers forum.
      It makes sense to set the valves on the high side of the range – too tight valves will add drag and could damage the engine, and loose valves can draw in a little more fuel mixture.
      I did not notice any extra noise or rattling, but if your engine is worn or the valve adjustment is a little high, it could rattle – but probably not much. The performance increase is subtle. You probably won’t notice this one change, but if you do it in combination with other changes (like higher tire pressure and iridium spark plugs), you might notice it.
      Regards,
      Les S.

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