HELP!

bike starts & runs fine until 9000rpm

At 9K the revs wiz round the clock with increased revs but no speed increase, almost as if it was a clutch slipping. but there is no problem below 9K or pulling away in any gear.

the bike is a 93 1000F with 74K miles.

Any suggestions?

bugkiller

 

Clutch issue , maybe weak clutch springs, or contaminated friction plates from
oil that has friction enhancers in it ! (some newer super slippery motor oils)

 

I agree, go for the clutch. If it's spun much you may need the steel plates too.

 

Let's make it 3 in a row for the clutch. I can't remember offhand where the max hp of our bikes is, but it's around there somewhere. It can't really be anything else...except the back wheel spinning of course.

 

Admittedly, you'd have to be pretty..er.. keen

 

Add on more for the clutch. AT peak power it's letting go. Has the bike seen STP or any other oil additive that would let the clutch spin? Maybe with frequent oil changes the additive would be flushed out. Or, the plates are to thin to hook up at power.

The good thing is you know what it is and you have a good running engine.

 

+1 on the clutch slipping.

Watch out for those fancy 'friction modifiers' used in some new oils. If the little circle says 'energy saving' the oil has the modifiers and they are bad, bad, bad on a wet clutch.

I use Rottella T, it doesn't have modifiers, latest certification and the only oil (other than brand name 'motorcycle oils') that is rated "MA" for motorcycles with wet clutch use. I use it in my '48 Case tractor which also uses a wet clutch.

Besides, it's really inexpensive at 'The Store That Sells Walls'

Change your oil (again, no friction modifiers) and add Seafoam to the oil. Ride it without slipping the clutch and then change the oil out at about 500 miles. See if the slipping is reduced, if not it is clutch time

 

Guys,

thanks for the advice - it makes sense as its just had an oil change using semi synthetic for the 1st time.
Going to swap it out tomorrow (& the filter) with good old fashioned oil.

hopefully that will cure it as the clutch seems ok below 9K. As for tyre spinning at 9K not that brave. 9K in 5th without a spin is enough

 

Been taking any mind bending drugs lately?
No?
Ok it's the clutch.
$100 in parts should see over the 9k hurdle without any fuss. (If you do it yourself).
Don't forget to buy a new clutch centre nut. And make sure you're got the 'special tool to remove it/tighten it.
You can possibly make one out of toilet roll and blue tack.... or cheese...parmizan?
Hang on a minute..... mind bending drugs. Um.... where am I?