Clutch

[manden]

hey all

is there any cluthc that will go in with none r minor mods? the standard clutch is very heavy, and im abut to change or renew it anyway.

i know of several clutch mods for the fj, but for now its a much lighter clutch im after or mod the standard clutchasembly throw off atleast 500grams.

thanks in advance

[fj1289]

Might need to see if a prior owner has already added a second spring or converted to a coil spring clutch?  FJ clutch is fairly light - and the diaphragm spring offers reduced lever pressure when pulled all the way in vice a coil spring conversion.

If not, only way I know to achieve what you want is with a lock up clutch - light springs for easy pull and enough weight on the arms to lock it at all rpm's.  Requires a spacer or custom clutch cover.   No one in the US makes lockups for these anymore - maybe in the UK for the XJR?

 

[manden]

im waiting for the gasket before further disassembly.

a complete fj 3cw clutch is 5.1kg+ that is 2 more than my gixxer 1100 clutch.

i have purchased a complete clutch, thats within specs, on fleabay that in gonna put together a decent clutch from

[fj1289]

You are talking about the weight of the individual components - NOT the effort required to pull the clutch lever?

If you are at the world class level of vintage racing I could see the "need" to lighten the clutch assembly.   But, for 98% of the riders out there, the stock clutch is robust and very capable - and simply adding a second spring takes care of nearly any high performance needs.  I think billet baskets are still available, but are likely to be heavier.  The FJ is not a light weight racer like the GSXR was meant to be - so I would want a more robust drive train to handle the additional weight and additional torque.

What mods do you have?  If you want more performance, the FJ motor was definitely under stressed and in a fairly low state of tune stock- it responds very well to big bores, head work, reasonable cams, carbs, etc.  50-60% increases in power are not difficult to attain and can be long lived and reliable.   

[manden]

You are talking about the weight of the individual components - NOT the effort required to pull the clutch lever?

If you are at the world class level of vintage racing I could see the "need" to lighten the clutch assembly.   But, for 98% of the riders out there, the stock clutch is robust and very capable - and simply adding a second spring takes care of nearly any high performance needs.  I think billet baskets are still available, but are likely to be heavier.  The FJ is not a light weight racer like the GSXR was meant to be - so I would want a more robust drive train to handle the additional weight and additional torque.

What mods do you have?  If you want more performance, the FJ motor was definitely under stressed and in a fairly low state of tune stock- it responds very well to big bores, head work, reasonable cams, carbs, etc.  50-60% increases in power are not difficult to attain and can be long lived and reliable.   

It was a lighter clutch i was after, not lever pull. Now that im rebuilding anyway. But have purched an ok used clutch and combining them to 7-1 with double spring.

Prolly doing head/valves, cams, carbs, exhaust. That should do 150-160@wheel

[fj1289]

Sounds like fun!

The double spring should be good with all good plates 

Post up in the projects section with your build - we like pictures and projects around here!

Oh - and where are you located?  That can help with sourcing parts and members in your area too

[racerrad8]

If trying to lighten the rotating mass of the clutch, there are a couple of tricks we've seen over the years.

A few that had the drive gear trimmed/thinned down. Lightening holes in the basket, the clutch boss lightened and the pressure plate lightened.

I have never checked, but I would imagine the coil spring pressure plate is lighter than the stock Yamaha assembly.

Randy - RPM

[manden]

Friction plates soaking in oil

[manden]

If trying to lighten the rotating mass of the clutch, there are a couple of tricks we've seen over the years.

A few that had the drive gear trimmed/thinned down. Lightening holes in the basket, the clutch boss lightened and the pressure plate lightened.

I have never checked, but I would imagine the coil spring pressure plate is lighter than the stock Yamaha assembly.

Randy - RPM

Thanks randy. Do the barnett spring conversion allow for 8 large friction plates?

Anyone knows how to attach pictures?

[manden]

Finally got around to swapping the clutch, and ofcourse large inner friction plate. Now i have no clutch... Any idea what happened? maybe clutch pressure shuld have been relieved before reinstalling?

[Pat Conlon]

"....and now I have no clutch" What does this mean? Please elaborate.

Have you read this? https://fjowners.com/index.php?topic=1808.0

[manden]

Yes i read it. And all seems to be fine. But the pushrod sits very low, and the clutch lever has no resistance. Im thinking it might just need to be pumped.

[fj1289]

If I remember correctly - you only replace the small bottom friction.  The top one has to remain small to clear the shoulder on the pressure plate.  I'll be a donut the large outer plate is keeping the pressure plate from compressing all the way down. 

I did have a pressure plate that someone tried to machine for a large friction.  As I recall it did not work well - I can't remember details now - but I remember the new machined edge chipping and pieces breaking off.  Pretty sure this was a lockup clutch assembly I had purchased. 

Some of the aftermarket pressure plate/coil spring conversions might allow for the larger friction on top?

[manden]

Pumped the clutch and bled it with all new fluid, and its back to normal.

Yes the inside flywheel needs to be surfaced for the new big plate to have full contact.

For now i run standard clutch with double diagram, and what a difference that made.

[fj1289]

Awesome!  No you can find you KOOKALOO!