Ericc1995 Posted April 12, 2020 Share Posted April 12, 2020 Hi everyone,I am restoring my fzr1000, i have already decided to use a yzf750 6 speed gearbox as the original 5 speeds are weak and an extra gear would be bliss. I am thinking about using yzf750 cam shafts aswell as they go right in and supposedly change the characteristics of the bike somewhat. I have not made any decisions as i think they may be more hassel then they're worth if i need to change the cdi aswell as it will take me out my budget for the rebuild. And finally what is the purpose of adjustable cam sprockets?Regards, Eric. Quote Link to comment Share on other sites More sharing options...
Ian Frog Posted April 12, 2020 Share Posted April 12, 2020 Hi EricFirstly have you checked the ratio of your new top gear? It is possible your top ratio is actually the same as your old box so you wont gain any overall performance but it might be nice to have the overall spacings of the ratios closer together.The adjustment for the camshaft allows you to alter the cam timing and is best done by someone with experience and hopefully access to a dyno so you can flatten out any bumps in your power curve (Or tune for max torque depending on your use).CheersIan Quote Link to comment Share on other sites More sharing options...
Ericc1995 Posted April 12, 2020 Author Share Posted April 12, 2020 Hi EricFirstly have you checked the ratio of your new top gear? It is possible your top ratio is actually the same as your old box so you wont gain any overall performance but it might be nice to have the overall spacings of the ratios closer together.The adjustment for the camshaft allows you to alter the cam timing and is best done by someone with experience and hopefully access to a dyno so you can flatten out any bumps in your power curve (Or tune for max torque depending on your use).CheersIan Thanks for the reply, thought it was timing tbf, i have binned the exup unit and it had an aftermarket exhaust when i bought it. It did run rough at idle tbf. And I'm replacing the box as the one of the cogs was broken, most were worn and the sprocket was welded . I also read the yzf box was less prone to wear.I will do more research when i get to the engine rebuild stage but i know for sure im gettingbit bored to 1040cc and bigger valves and head work done. Fcr carbs would be preferable but thats £1000 vs £100 for a stage 3 kit for the old cv carbs. Quote Link to comment Share on other sites More sharing options...
megawatt Posted April 13, 2020 Share Posted April 13, 2020 If you fit higher lift cams, you need to check the valve to piston clearance. The cam duration also affects this as minimum clearance is not necessarily at top dead Centre. Adjustable cam sprockets allow the cam timing to be varied to increase power and maintain clearances. Quote Link to comment Share on other sites More sharing options...
Ian Frog Posted April 13, 2020 Share Posted April 13, 2020 If you fit higher lift cams, you need to check the valve to piston clearance. The cam duration also affects this as minimum clearance is not necessarily at top dead Centre. Adjustable cam sprockets allow the cam timing to be varied to increase power and maintain clearances.Much better explained than my ham. fisted effort lol.CheersIan Quote Link to comment Share on other sites More sharing options...
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