Camshafts
About Camshafts
A camshaft opens the valves through its lobes, and the shape of those lobes sets when and how far each valve opens. Riders replace one that is worn or damaged, or fit a performance cam to change how the engine makes power. This category also holds timing parts for specific machines: cam chains, silent chain kits and a cam chain tensioner.
Performance cams here are labeled Stage 1 or Stage 2 for named machines, such as the Yamaha Raptor 700R and the Polaris Predator 500. The stage is the maker's way of ranking how aggressive the cam profile is, and a higher stage usually calls for more supporting work, such as stiffer valve springs, careful cam timing and fuel tuning. Read the maker's notes for what else your engine needs. Cam chains are listed by machine and year, and a worn one is best replaced while the cam is out. Use cam assembly lube on the lobes when you install a new cam, and follow the break-in instructions.
Brands in this category include PSR, ProX and Hot Cams. Pick your machine in the Ride Finder at the top of the page to see cams made for it. Parts that go with a cam change are Valve Guides, Springs & Parts, Engine Valves and Rocker Arms & Parts. The whole group is Valvetrain Component.
FAQs on UTV and ATV camshafts
What do Stage 1 and Stage 2 mean on a racing camshaft?
Stage numbers are a maker's way to rank how aggressive a cam is. A higher stage generally changes valve timing and lift more, and often needs stronger springs and tuning to match. The definitions differ between makers, so read the listing notes for your machine.
Do I need to tune the engine after installing a performance cam?
Often yes. A new cam changes how much air the engine moves, so a carbureted machine may need jetting changes and a fuel-injected one may need a fuel controller or a new map. Check the cam maker's instructions for your model.
Should I replace the valve springs when I fit a new cam?
It depends on the cam. A stock-profile replacement uses stock springs, but a more aggressive cam often needs stiffer ones so the valves close properly at higher engine speeds. The cam maker's notes will say which springs to use.
How do I install a new camshaft?
Remove the cam cover, set the engine to the timing marks in your service manual, and fit the cam with assembly lube on the lobes and journals. Then set the chain and check valve clearance. If this is new to you, a shop can do it.
Should I replace the cam chain when I change the camshaft?
It is a good time to. The chain is accessible while the cam is out, and a stretched chain will wear new parts. Inspect the chain, tensioner and sprockets and replace anything that shows wear.
