Dare I say it.................oil

[andyb]

Before we talk about returning the clutch to OEM spec and why it isn't working as it did when new...

The rest of the bike is stock as well then yes?  You're still using a tire designed in the 80's, of the stock size?

A friend's VMax had a similar problem.  The stock clutch was fine, but he could fry the tire through third gear on the right type of pavement.  No problem, a bit more meat for the next tire gave him the grip he was looking for.... except that the clutch started slipping.  Turns out it it wasn't the weakest link until the tire was uprated.  Improving his clutch with another spring (they're quite similar to the FJ internally) gave him the ability to really put the power down.  Until the driveshafts started breaking.  He's been through three, I think, and everything is properly aligned and in good working order.

Apparently he's got a good motor in his `max.  Even with the motor causing clutch slip, he was quite significantly quicker than another very similiar Vmax (his is a 93, and he walked away from a lighter rider on a healthy `85).


The clutch is only one link in a fairly long string of things that puts power to the ground... A lesson I learned rather expensively with a car some years ago.  (New tires mean the ujoints went, then the clutch fried, then the diff exploded, then the bellhousing cracked, then the trans did... then I sold the SOB before I went totally broke!)


All that said, I have to also point out that a coil spring conversion can and will increase the pull required at the lever.  It's a direct linkage of sorts, so the energy is coming from your fingers = more clamping force = more clamping force to overcome.  A smaller bore master cylinder will fix this.  That said, you don't have to use the springs that come with the conversion kit.  If you wanted to get fancy, I'd wager you could find something lighter than what's included, yet heavy enough to do the work.  You'd be on your own a bit, but I'm sure some research would provide a solution (at worst running half the springs of a much heavier form or something).

[Mark Olson]

This is a serious question, I repeat, a serious question!

Does anyone here have a standard (ie power) motor and standard clutch running on synthetic oil that they KNOW FOR A FACT does NOT slip above 6k rpm and WOT in the higher gears.

Noel

hey Noel , I have your answer . 

I have documented research and testing on this very subject exactly fitting your criteria .

my 86 fj1200 was previously owned by a friend of mine and the testing started in 2001.

in 2001 the 86 was totally stock with 5k miles on it. running on dino oil the clutch did not slip at all in any gear or rpm when my 250lb friend rode it.

I was 280lbs at that time, and when I rode the fj it would only slip the clutch at red line power shifts , wot balls out . but it held for my friend when he did it.

the extra 30 lbs rider weight made all the difference in how much a stock clutch could take.

I talked him into synthetic motorcycle specific oil (amsoil) and now the clutch slipped for both of us for a period of 200 miles till the clutch fibers got used to it.

now the clutch went back to full strength with no slipping for either of us no matter how it was abused.  the only exception was a very hot day (over 105 degrees )

The time was 2001-2003 , location of testing was desert hot springs Ca. during all times of the year . Hard to believe I didn't run into Pat back then. 

Anyway how I ended up with the 86fj is another story.

moving forward :
I am currently testing Zari's fj with a stock clutch , we removed the small fiber and replaced it with a full one and replaced the old spring with a new one.

It has been 2 yrs now with this setup and it works great on synthetic oil. no slips at all and the clutch pull is nice and easy.

This would be my current recommendation to any one who wants to beef up their clutch.

I hope this helps you in your search for kookaloo.   

[jvb_ca]

Hey Noel. I have been using Rotella T Synth 5w40 for the last couple of seasons. No slippage. I also have my clutch spring doubled up with FJR spring and 14mm master cylinder. Smooth a silk...  and has the ultra trick adjustable lever.

Cheers...Jake