DIY XT-225 valve adjust klm4755 (Minor Revisions and PDF conversion by RickMJr) Here is a step by step process for conducting a valve adjustment on a Yamaha XT-225. The Bike in the photos is a 2005 model. Make sure the bike is in neutral, fuel shut off, and is cold (not ran in the past ~8 hours). Please feel free to add to the steps with you tips, tricks, and tribal knowledge for the benefit of all! 1) First Step, remove side covers using a Phillips head screw driver. The right side:

The left side:

Side Covers removed.

2) Remove the seat using a 10 mm socket + ratchet.

The seat removed.

Here’s a view of the XT with the seat and side covers removed.

Close up view of the left side.

3) Remove the gas tank side covers next using a 10 mm socket with 4" extension. Unsnap the grommet on each side. Pull away towards the front of the tank to release attach stake.

Below are the covers off.

4) Next, unhook fuel line from fuel cock assembly or the carburetor. The first photo shows a fuel filter that was installed by the owner.

The carburetor side:

The fuel cock side:

Be sure to use a rag to catch dripping gas.

5) Remove the gas tank bolt next using 10mm sized socket. There should be three parts: bolt, tank washer, and locating damper.

Below is the tank with attach parts off

Important! Make sure fuel cock tank valve assembly is not supporting tank weight, let it overhang like this

6) Remove the gas tank bracket. Note, this bracket may lift with the tank. That is ok

Tank bracket (special washer and locating damper) removed

Gas tank brackets and associated parts are shown below.

7) In order to turn the engine, remove this crank case plug with a large standard screwdriver.

8) To view the crankshaft location remove this plug also.

9) To remove the valve cover you’ll need a 5mm allen socket and a 5mm allen key. There are five 5mm allen head bolts, all of same size (diameter and grip length), so don’t worry about mixing them up.

9a) Start the exhaust side (front cover). There are three allen head bolts to remove. The allen bolts closest to you can be removed with the socket. The others require the allen key.

9b) Next remove the two bolts on the intake side (rear cover). Again the closest bolt can be removed using the allen socket. The other bolt requires the allen key.

9c) Here’s a photo using the allen key to remove a bolt.

9d) Photo of the exhaust cover off

9e) Photo showing the intake cover off.

All engine access parts off; we will inspect these parts later

Here’s a close-up of the Intake valve.

10) Attach 17mm socket to this crankshaft bolt, use small 4" extension

As shown in the photo below, rotate counter-clockwise while looking in the view port hole

look in here

These are the 3 radial groves on the flywheel, the one in the middle is top dead center (TDC), however a four stroke engine may read bottom dead center ( I’m not that sure about this statement). However, it is not important. What is important is to check the exhaust gap while you have the center groove visible. If you can get a .003" feeler gage in the gap your at TDC. If not rotate the flywheel another 360 degrees counter-clockwise and check the gap. This time it will be there. So, you have a 50/50 chance of getting it right the first time. By the way don’t use the ratchet function on your tool. Once you see the flywheel notches, just spin your tool one full revolution to see notches again!

11) Need specifications for valve gaps. Do exhaust first .006 to .007 inch

Need right feeler gauges

This photo shows the exhaust valve and gap.

Using the feeler gauge, determine if valve adjustment is necessary. If the .007 inch feeler gauge easily fits the gap is too big. If the .006 inch feeler gauge doesn’t fit, the gap is too small.

12) To aid in adjusting the valve gap use a valve tool. Some folks use needle nose pliers. A valve adjusting tool makes this job a lot easier. Use 3mm side. It will hold the valve adjust bolt steady while you tighten the valve lock bolt.

12a) Loosen lock bolt with 10mm open end socket, adjust valve with tool, check with feeler gage. When the gap is correct, hold the valve steady using the valve tool or needle nose pliers and tighten the lock nut. Don’t let valve spin with locknut. This is where the valve tool is handy! Be sure to double check valve gap after you have tightened the lock nut. Correct if necessary.

13) Torque lockbolt with torque wrench to 10 ft*lbs, but torque wrench may not not fit so.....

Use an open end socket like this!

Torque wrench in action

14) Repeat the same procedure for the intake valve but use feeler gauges between .002-.004 inches.

Determine if the intake valve gap is too small or big.

This gap is too big, need to adjust.

14a) Adjusting intake valve using the valve tool and open end wrench.

Tighting the intake

15) Torque the intake valve locknut to 10 ft*lbs

16) Inspect exhaust valve cover, wipe it down with a clean cloth and make sure the seal looks good.

17) Inspect intake valve cover too. Clean and inspect the rubber seal.

18) Clean valve cover/engine case surfaces.

19) Install the exhaust and intake valve covers.

20) Clean and inspect the crankcase plugs. Verify that the O-rings are OK. Screw the plugs back on.

21) Torque the two allen head cover bolts that are accessible by the torque wrench (one intake and one exhaust) to 7.2 ft*lbs. Other three allen head bolts will need to be attached by allen key, no room for torque wrench. Just remember that 7.2 ft*lbs is just barley tighter than snug. Here’s the intake side.

And the exhaust side

22) Replace the gas tank bracket and damper. Install the gas tank with the rounded groove rails first (the front of the tank) and then bolt it down.

23) Torque the gas tank bolt to 5 ft*lbs.

24) Reattach fuel line.

25) Reattach tank covers. 26) Reattach seat by installing the front side first and then attach the rear side bolts. 27) Reattach the side covers top end first, popping them back into place, then screw them back in. All buttoned up and ready for a test ride. Results - no pings thru any of the throttle/gear ranges.