Cam Chains and Cam Chain Tensioners

Do you have a rattle in your cold engine that (mostly) goes away when it is warmed up?

(From Dave Dodge)

Honda revised the design of all the V-4 cam chain tensioners as they found the tensioner would run out of tension travel before the chain reached its wear limit. The newest design for the V65 was not released until 1989, after the bike was out of production. The newest design vs. the stock 1983 tensioner has a different arm pivot angle that allows it more tension travel. Plus the tension spring has added tension and does not fully collapse, and the locking bar is thicker so as to not come loose.

To determine if you need the updated tensioners, remove the valve covers and alternator cover to do a physical inspection. Rotate the engine for 2 complete revolutions, stopping at each 90° interval. At each checking point reach up to the chain and check its tightness. If at any point you can push the chain down and away from the top guide, you should install the updates. It is possible for the chain to go loose in only one checking point, and if it does it will cause a rattle noise in the engine. And if it gets too loose (like on the '83 with the earliest style), it is possible for the chain to jump a tooth on the cam sprocket(s).

It is not necessary to remove the cams for this, nor is it necessary to remove the engine from the frame. Changing cam chains is a bitch unless you use master link type chains, because you have to tear the engine down to the crank, and the engine/tranny of a V65 weighs around 200 lb.

New Tensioners:

• V65: Shorten the rubber sleeve on the spring by 5/8".
• V45: If the sleeve bunches when the lock pin is pulled and the tensioner is in the full tension position, shorten the rubber sleeve by 1/2".
  • This check should be down "before" the tensioner is installed.