{"product_id":"prootom-adjustable-valve-shim-kit-for-450cc-motocross-bikes-9-48mm-141-piece-1-20-3-50mm-0-05mm-steps-steel-shims","title":"PROOTOM adjustable valve shim kit for 450cc motocross bikes — 9.48mm 141-piece (1.20–3.50mm, 0.05mm steps) steel shims","description":"\u003cstrong\u003ePROOTOM OTOM D9.48mm 141-piece adjustable valve shim kit supplies a complete range of steel shims (1.20–3.50mm in 0.05mm steps) to restore and fine-tune valve clearances on 450cc off-road bikes.\u003c\/strong\u003e\n\n\u003cp\u003eThis comprehensive shim kit gives mechanics and home riders the parts they need to service shim-over-bucket valve trains on popular Japanese 450cc motocross and enduro models. It includes three shims per size across the range, enabling precise adjustments without sourcing individual shims. The parts are made of steel, sized to a 9.48mm diameter, and designed to be compatible with CRF450R, CRF450X\/RX, YZ450F and WR450F platforms as well as many KXF, KX, KLX, RMZ and YZF variants that use the same shim dimensions.\u003c\/p\u003e\n\n\u003ch3\u003eHow does this kit make valve maintenance easier?\u003c\/h3\u003e\n\u003cp\u003eThe kit eliminates repeated trips to suppliers by providing a full spread of shim thicknesses in 0.05mm increments, so you can achieve the exact clearance required. With three pieces of each thickness, you have spares for rechecks or twin-cylinder applications. The shims are pre-sized for straightforward fitment into shim-over-bucket valve systems.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e141 pieces cover 1.20–3.50mm in 0.05mm steps\u003c\/li\u003e\n  \u003cli\u003eThree shims per thickness for redundancy\u003c\/li\u003e\n  \u003cli\u003eSteel construction resists wear during installation\u003c\/li\u003e\n  \u003cli\u003e9.48mm diameter fits common 450cc valve buckets\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWill these shims fit my CRF450 or YZ450F engine?\u003c\/h3\u003e\n\u003cp\u003eThe kit is manufactured to the 9.48mm diameter standard used on many Japan-origin 450F off-road engines. It's intended for CRF450R\/X\/RX, YZ450F and WR450F models and fits other brands that share the same shim diameter and valve train layout. Always verify your motorcycle’s service manual for recommended shim diameter and clearance ranges before installation.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eCompatibility: CRF450R, CRF450X, CRF450RX, YZ450F, WR450F\u003c\/li\u003e\n  \u003cli\u003eAlso fits many KXF, KX, KLX, RMZ, YZF 450 models with 9.48mm shims\u003c\/li\u003e\n  \u003cli\u003eCheck service manual for shim-over-bucket specifications\u003c\/li\u003e\n  \u003cli\u003eNot for non-matching diameters or different valve systems\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow precise are the shim increments and why that matters?\u003c\/h3\u003e\n\u003cp\u003eShims are supplied in 0.05mm increments, providing fine control over valve clearance adjustments. Smaller increments let you reach the factory-specified clearance without overcompensating, which helps maintain performance and reduces the risk of valve noise or premature wear. The 0.05mm step is standard for accurate valve setting work on high-performance 450cc engines.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e0.05mm increment sizing for accurate clearance tuning\u003c\/li\u003e\n  \u003cli\u003eCovers 1.20–3.50mm to suit many clearance requirements\u003c\/li\u003e\n  \u003cli\u003eThree items per size allow staged changes and backups\u003c\/li\u003e\n  \u003cli\u003eBetter fit helps reduce valve train noise and wear\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat’s included and how do I use the kit?\u003c\/h3\u003e\n\u003cp\u003eThe kit contains 141 steel shims, each 9.48mm in diameter, spanning 1.20mm to 3.50mm. Use a feeler gauge and your motorcycle’s specification sheet to measure current clearances, then select the shim thickness that brings the clearance into spec. Replace the shim-over-bucket shim carefully and recheck clearances after a few heat cycles.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e141 steel shims total, organized by thickness\u003c\/li\u003e\n  \u003cli\u003eRange: 1.20mm through 3.50mm in 0.05mm steps\u003c\/li\u003e\n  \u003cli\u003eIntended for shim-over-bucket valve configurations\u003c\/li\u003e\n  \u003cli\u003eUse with feeler gauge and service manual measurements\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: This PROOTOM OTOM valve shim kit is aimed at professional tuners, independent mechanics, and experienced riders who perform valve maintenance on Japanese 450cc off-road engines. It’s useful for anyone who needs a complete set of replacement shims for frequent rebuilds, track-season prep, or to carry as a workshop or race-day spare supply. If your motorcycle uses 9.48mm shim-over-bucket valves and you want precise, incremental adjustment options without sourcing individual sizes, this kit is a practical and cost-effective choice.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Does this kit fit CRF450R models?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. The kit uses 9.48mm diameter shims compatible with CRF450R\/CRF450X\/RX when those bikes require 9.48mm shim-over-bucket parts.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: What thickness range and increments are included?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: It includes shims from 1.20mm to 3.50mm in 0.05mm increments, with three shims for each thickness.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"PROOTOM","offers":[{"title":"Default Title","offer_id":48079867904158,"sku":"B08KW13W9F","price":105.48,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/prootom-otom-front-packaging.jpg?v=1785773510","url":"https:\/\/northtrailauto.ca\/products\/prootom-adjustable-valve-shim-kit-for-450cc-motocross-bikes-9-48mm-141-piece-1-20-3-50mm-0-05mm-steps-steel-shims","provider":"North Trail Auto","version":"1.0","type":"link"}