The program for the timing belt is every 50k miles. Most of us would opt to replace it if in doubt. The B230 is a non interference engine so when the belt snaps (and they do) it will not destroy valves and pistons but it will stop you dead in your tracks. Its not that difficult to remove the pulley and slap on a new belt There are several methods to get that big bolt loose including the rope trick. I believe they are documented in the 700/900 FAQ sections. Much of that FAQ info is the same for your 240 engine. If you can remove the head you can do a timing belt.

The front crank pulley (AKA harmonic balancer, vibration damper) of course is keyed to the crank. However it is in 2 pieces, an inner and outer section, bonded together with a rubber insert. The inner section is on the crank and the outer section is the pulley part with that all important timing mark. Sometimes the rubber bonding lets go and outer section can slip, it may not spin freely but just slip a bit. This of course renders the timing mark useless and means you cannot set the timing as you planned. Not common but it does happen. Maybe I have brought up a bit of a Red Herring but it happened to me once and boy was I fooled for a when i tried to look at my ignition timing.


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David Hunter