Somethings not right....Clutch maybe ???

[mcn2008]

Hi Guys, looking for some feedback/advice etc.

1st day out on the new bike, a wee blast down the duel carrage way and in 5th gear at 8000 rpm the bike is doing 70 mph which is not right.
Clutch did not feel like it was slipping so i checked out the final drive.. 17 tooth on the front and 39 on the back as it should be ?

Going through the gears i would say that the revs are to high for the speed in each gear. 1st is about 30 od mph around 8000rpm approx.
It goes up and down the gears ok.

If it is the clutch i would have thought there might have been some waver in the tacho needle but its stable. Its just plain weird.

Any ideas ??

Cheers
Mark

[Pat Conlon]

uuuh yea, 8k on the tach and 70mph in fifth, I would say that your clutch is slipping.... Open up the clutch cover and take a look, it's easy.

As my friend Leon said, "You can't find your kookaloo with a shitty clutch".

[mcn2008]

Its just weird that the clutch doesnt apear to be slipping but its obviously is 

[Mark Olson]

tach it up and try to start off in 3rd gear by dumping the clutch, if the engine stalls clutch is good , if it slips all to hell and you move forward and go your clutch is shit.

you may just have a bad ground on your tach and it is reading a false high rpm.

standard gears are 17-41 early fj and 17-42 later models.  so 75-80 mph is 5k rpm.  with a 39 rear you should be lower rpm than 5k.

the fj normally starts slipping its clutch at 6k rpm when it hits the kookaloo zone at full throttle.

[mcn2008]

well i have tried out the clutch dump at an indicated 8k oe there abouts and it stalled. tried it a couple of times and the it was the same. clutch doesnt feel like its slipping so it may be a fals reading...doesn't sound like it though but i will check out the wiring.

[Mark Olson]

check your tach reading against a remote one if you have it. if not ride it and wind it up in 2nd gear till the engine hits the limiter or floats the valves ,and see what the

tach reads . should be around 11k . oh and very important to hold on tight ,cause it's a wild ride.

[mcn2008]

Just read a very interesting thread on here base around the tach showing double what it should. It was then that i remebered it was idling at 2k. so a bit more investigation on my part in the wiring department and i will see what happens.  I wondered about the limiter because i took it up the 100mph and it didn't hit the limiter, no idea what the tach was reading at the time, it was before i noticed the problem. Its very un nerving seeing the needle in the red 
cheers for thhe advice 

[andyb]

Just compare the speedo and tach.  If they move linearly in a given ratio, then it's the tach misreading.  If the tach jumps up and hangs a moment while the speed catches up, it's the clutch.  You could also just compare 30mph on the speedo as whatever rpm, 60mph should be double it precisely, and 90 should be triple it.  If the clutch is slipping, it's going to be easiest to find when the bike is really loaded hard against a stiff headwind and making power....

[mcn2008]

Cheers Andy thats usefull, i will give it a go today. Almost certain its not the clutch as i was watching the tach yesterday and it never jumped once but the other things you suggested should confirm the problem. 

[mcn2008]

Well after pulling the bike to bits and a bit of troubleshooting, the tacho itself is knackered. found a set of clocks on ebay so hopefully they will do the job.
Its amazing how easy it all comes apart compared to my wing lol.
Should be back on the road this weekend coming if i can get the time to get near it !!
Cheers everyone 
Mark