Need Help Engine Revs Out without Speed Increasing in High Gears

dweisman83

New member
I recently purchased my FZ8 from FB marketplace and I noticed something odd when I was riding. I noticed that only when I'm in higher gears and revving at around 6-7k rpm and I try to throttle the bike agressively the bike revs to redline but the speed doesn't increase. It sounds and looks like I pulled in the clutch and redlined it however I'm not on the clutch at all. I tried doing this in lower gears like 1st and 2nd but didn't notice this to be an issue as when I got on the throttle hard it would instantly gain speed (as expected).

For example, I was in 4th gear (maybe it was third) doing about 70/75 mph at about 6-7k rpm and I tried throttling hard to go faster and the bike just redlined and didn't accelerate at all. Even when holding the throttle there it didn't gain nearly enough speed to be redlining in that gear. I tried doing this in first and second gear at about 50 mph and it accelerated very quickly like normal.

Some relevant information is that the bike has about 8.5k miles. I only noticed the issue after I installed an ASV clutch lever and there was some difficulty getting it to fit in and slide well because I forgot to grease it before installation. However I only rode the bike a handful of times with the previous clutch (some aftermarket one from china) so I never throttled hard in higher gears because I was still learning the bike. I'm thinking it could be either the spark plugs going bad or possibly installing the clutch wrong or maybe even a slipping clutch. If you guys have any other ideas and any solutions please let me know.

Thank you!
 

dweisman83

New member
Sounds very much like clutch slip. Back off the cable adjustments and reset to spec especially the free play at lever end.
I did some more testing today, I found out the bike has a real tendency to not want to go past 90 in any gear. Does that still sound like slipping clutch or dying spark plugs?
 

Jacko

New member
Hi, that sounds like a whole different issue if it is increasing speed with revs but not reving out all the way. Plugs can cause these issues under load. Check plug condition.
 
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