Would it matter if the crank shafts on top dead center on the exhaust stroke? What does it have to be on the compression stroke? Because if I put the timing marks in line with the top of the engine, it's always starting off on the exhaust stroke unless I flip the lobes around. Any help would be awesome on the timing

  • Welcome to Motor Vehicle Maintenance & Repair! Dec 12, 2023 at 1:27

1 Answer 1


It will never be at top dead center (TDC) on the exhaust stroke, because the exhaust stroke starts at bottom dead center (BDC) and finishes at TDC (approximately). If you tried to align the cam(s) this way, you're going to have collisions between the piston and the valves on any interference engine, which I assume your Honda has.

EDIT: What I'm getting at by saying this is, if the only way your timing marks line up is with the cams being on the exhaust stroke (I'm assuming your exhaust valves are open?) when the piston is at TDC, I'm thinking you've got something wrong. Considering you've already stated the only way you can get it right is by swapping the cams ... are you sure you don't have them backwards in the first place?

  • They have marking on each valve lobe for intake and exghast so there on the right sides I just been trying to time this bike and idk what I'm doing but another of people show pics of where the timing marks should be at tdc on the compression stroke but the exhaust opens first the valves not stuck open I think something is wrong in the time I just don't know what Dec 12, 2023 at 18:14

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