Motorcycle & ATV Crankshaft & Bottom End Rebuild Buyer's Guide for Canada

Whether you're nursing a seized two-stroke back to life after a long Canadian winter or refreshing the bottom end on your ATV before another season of trail riding in the Laurentians, a crankshaft and bottom end rebuild is one of the most rewarding — and most involved — jobs you can tackle in your garage. Done right, it breathes new life into an engine that might otherwise end up as a parts bike. Done wrong, it can cost you more than a replacement motor.

This guide is designed to help Canadian riders and wrenchers understand what goes into a bottom end rebuild, what parts you'll need, and how to source quality components without overpaying or waiting weeks at a dealership counter.

What Does a Crankshaft & Bottom End Rebuild Actually Involve?

The "bottom end" refers to everything below the cylinder — the crankshaft, connecting rod, main bearings, crankcase, crankcase seals, and transmission components depending on your application. When any of these parts fail or wear beyond spec, you'll typically notice symptoms like excessive engine vibration, knocking or rattling at low RPM, oil leaks from the crank seals, or in the worst case, a seized or grenaded motor.

A full engine rebuild at this level usually includes:

• Crankshaft inspection, truing, or replacement
• Connecting rod and wrist pin replacement
• Main bearing and crankcase bearing replacement
• Crank seal replacement (left and right side)
• Crankcase gasket set
• Transmission shaft inspection and bearing replacement if needed

On two-stroke engines — common in motocross bikes, snowmobiles, and smaller ATVs — crank seal condition is especially critical. A leaking crank seal can lean out the fuel mixture and cause catastrophic damage quickly, particularly in our colder Canadian climates where engines are often pushed hard after a cold start.

Choosing the Right Engine Rebuild Parts: OEM vs. Aftermarket

One of the biggest decisions you'll face during a bottom end rebuild is whether to go OEM (original equipment manufacturer) or aftermarket. Both have their place, and the right answer depends on your budget, your riding style, and how the machine is used.

OEM parts are made to the exact factory specification and are generally the safest bet for street-registered motorcycles, particularly if you're in a province like Ontario or British Columbia where emissions and mechanical standards may affect insurance or inspection requirements. The downside is cost — OEM crankshafts and rod kits can be expensive, and availability through Canadian dealers can be slow.

Aftermarket parts from reputable brands like Wiseco, Hot Rods, All Balls, Vertex, and Prox are engineered to meet or exceed OEM spec and are a favourite among recreational and competitive riders alike. Many Canadian powersports enthusiasts find that aftermarket kits offer better value, especially for older bikes where OEM parts are discontinued.

If you're shopping for crankshaft and bottom end rebuild parts, Moto Deals carries components from over 108 trusted brands, covering motorcycles, ATVs, UTVs, and more — all shipped right to your door across Canada.

Key Measurements & Specs You Need Before You Order

Before you click "add to cart" on anything, you need to know your exact specs. This isn't a step you can skip. Ordering the wrong rod kit or a crank assembly with the wrong stroke can mean wasted money and downtime — and nobody wants their bike sitting on the bench heading into riding season.

Here's what to have on hand before ordering:

1. Year, make, and model — and if possible, the VIN or engine number
2. Engine displacement — some models have multiple engine variants
3. Stroke measurement — relevant if you're considering a stroker crank for performance builds
4. Main bearing size — measure the crankcase bore if in doubt
5. Big end rod journal diameter — critical for connecting rod fitment

If you're unsure about fitment or compatibility, don't guess. Contact our team at Moto Deals and we'll help you find the right parts for your specific machine.

Shipping & Availability for Canadian Powersports Riders

One challenge Canadian riders know well is the frustration of cross-border shipping delays, customs fees, and duty charges when ordering from US-based retailers. Moto Deals is a Canadian online powersports dealer, which means you're not rolling the dice on border delays or surprise brokerage fees when your engine rebuild parts are on the way.

Whether you're in rural Saskatchewan, the interior of BC, or just outside Halifax, we ship coast to coast. Orders over $100 qualify for free shipping — which is easy to hit when you're stocking up on a full bottom end kit, gasket set, and crank seals at once.

Spring is when most riders start tearing things apart, but winter is actually the best time to order rebuild parts. Suppliers are better stocked, you have the time to do the work properly, and you'll be ready to ride the moment the snow clears — whether that's March in southern Ontario or June in northern Alberta.

Getting the Most Out of Your Engine Rebuild Investment

A crankshaft and bottom end rebuild is an investment in the long-term health of your machine. To protect that investment, pair your bottom end work with a fresh top end if the piston and cylinder are near the end of their service life. Doing both at once saves you labour time and ensures the whole engine is starting fresh together.

Also don't cut corners on assembly. Use a torque wrench, follow the factory service manual for your model, and always replace seals and gaskets — never reuse them. A few dollars saved on a crank seal can turn into a much bigger repair bill down the road.

With the right parts and a bit of patience, a bottom end rebuild can add thousands more kilometres to a machine you already love — and cost a fraction of what a replacement engine or new bike would run you. To get started, browse our 108+ brands and find the components that fit your build.