2020 Kawasaki KLX140 Valve Adjustment - Page 1

This is a step-by-step guide to checking and adjusting the valve clearances on a Kawasaki KLX140. It is based on the author’s observations and experience performing a valve clearance adjustment on a 2020 Kawasaki KLX140L and on information contained in the official Kawasaki KLX140 service manual, 2020 (part no. 99924-1390-14) which covers model years 2008 - 2021 and models KLX140A/KLX140/KLX140R, KLX140B/KLX140L/KLX140RL and KLX140C/KLX140G/KLX140RF. The author is not aware of any mechanical changes to the KLX140 models for the model years 2022-2024, so this guide should apply to those as well. Check with a Kawasaki dealer if in doubt or get the latest version of the service manual.

Read all of the instructions before beginning. It may be helpful to take photos of the bike prior to removing or repositioning parts to aid you later.

To follow the valve clearance inspection and adjustment procedure in the service manual will require you to reference multiple sections in it (lots of jumping back and forth through the manual). There is also some contradictory information. The service manual skips over a few points that would be helpful to know in advance. This guide attempts to fill in some gaps in the service manual, help clarify some points, provide better photos and offer some suggestions to make the valve clearance adjustment procedure a little easier if you're not that familiar doing this sort of thing. The procedure is relatively easy, especially compared to some other bikes that I have adjusted the valve clearances on.

On the KLX140 series, the valve clearances are adjusted via screw-type adjusters (the camshafts do not need to be removed and there are no shims to replace). Use the correct tools for the job, and take your time.

Disclosure: While the author has attempted to provide correct and complete information, sometimes errors or omissions may occur. By using this document and following the procedures and advice below, the user assumes all risk and responsibility for injury or damage to their motorcycle. The author has been servicing motorcycles for many years (not as a profession) and is mostly self-taught (no formal training in motorcycle servicing). It is recommended that you consult the Kawasaki KLX140 owner’s manual and/or service manual.

Parts and supplies you may need

• new valve adjusting cap gaskets if the existing ones are hard, deteriorated or damaged
• new O-ring (gasket) for the alternator cover center cap (crankshaft hole cap) if the existing O-ring is hard, deteriorated or damaged
• new O-ring (gasket) for the camshaft chain cover if the existing O-ring is hard, deteriorated or damaged
• new O-rings (gaskets) for the valve adjustment caps if the existing O-rings are hard, deteriorated or damaged
• motorcycle engine oil that you currently use for your bike
• multipurpose grease
• silicone spray and/or grease
• shop towels, rags
• plastic cap or plug, etc. to plug end of fuel line (1 ml syringe cap, insulin pen needle cap, golf tee, etc.)
• pen and paper
• a camera

Tools you need or may find helpful

• accurate torque wrench (8 to 13 N.m range)
• possible 3/8-inch to 1/4-inch adapter
• 1/4 inch drive ratchet, 6 inch and 3 to 4 inch extensions, 8 mm socket
• 3/8 inch drive ratchet, 3 or 6 inch extension, 9, 10 and 12 mm sockets
• deep socket or special spark plug socket (if removing the spark plug)(
• flex-bar or T-handle (3/8 inch drive)
• 9 and 12 mm box-end wrenches
• #3 Philips screw driver
• tool for the valve adjusters which have 3 mm square ends (special tool or 3 mm open end wrench)
• tool to remove the alternator cover plug (I use a Motion Pro timing plug wrench)
• feeler gauges to measure the valve clearances (see valve clearances below for sizes)
• pliers to release and move the fuel line clamps
• flat blade screw driver to remove the fuel line (or a fuel line removing tool)

Information from the Kawasaki KLX140 Service Manual

• Remove the fuel tank. [Involves removing the side covers, seat and tank cover/shroud and disconnecting the fuel line.]
• Remove the valve adjusting caps.
• Remove the camshaft chain cover.
• Turn the crankshaft bolt counter-clockwise with a wrench (see note below). Making sure that the intake valve opens and then closes, continue to turn the crankshaft bolt until the mark on the camshaft sprocket aligns with the projection on the cylinder head. The piston is now at TDC on the compression stroke.
• For each valve, measure the valve clearance between the adjusting screw and the valve stem using a thickness gauge.
• If the valve clearances are not within specification, adjust the clearances by loosening the locknut and turning the adjusting screw. Tighten the locknuts to 8.8 N.m (78 in.lb).
• Install the valve adjusting caps. Grease each O-ring (replacement part). Tighten the bolts to 8.8 N.m (78 in.lb).
• Install the camshaft chain cover. Grease the O-ring (replacement part). Tighten the bolts to 8.8 N.m (78 in.lb).
• Install the alternator cover center cap. Grease the O-ring (replacement part). Tighten the cap to 2.5 N.m (22 in.lb).
• Install the fuel tank and reconnect the fuel line. Install the fuel tank cover, seat and side covers.

Note: You will first need to remove the alternator cover center cap. In one location in the service manual, it states to turn the crankshaft clockwise, and in another location, it states to turn the crankshaft counter-clockwise. In another part of the service manual, the text contradicts the diagram showing direction of manual crankshaft rotation. The service manuals I have for other motorcycles all state to rotate the crankshaft counter-clockwise, when viewed from the left side of the engine (rider facing forward).