620 clutch questions

[mmmpizza]

Just picked up a 2004 Monster 620.  Cool bike, seemed like a pretty good price.

The clutch was slipping occasionally, then after a few long afternoons romping it through some canyons it began to slip all the time at more than half throttle.

I looked a little more closely at the aftermarket adjustable levers (which were installed by the PO) and it appeared they were holding the clutch actuator in just a very little bit all the time.  I put the original levers back on and bled the system, and now there is no slipping but the clutch still doesn't grab until it's let out damn-near all the way.

Is this normal or should I be shopping for a replacement?  The bike only has 8,500 miles on it... seems it should last much longer than that.

Thanks

[BK_856er]

Wet clutch slippage is usually caused by (a) improper oil or non-ideal oil, or (b) improperly adjusted master cylinder actuator, especially after aftermarket levers are installed.  8.5k miles is pretty low for a wet clutch to wear out, but who knows how the PO rode it.  Late lever with short friction zone is typical for the aptc type wet clutches (came later than '04??).  Running an OE clutch slave?  Bleed the heck out of it?  Ziptie the lever overnight and see if that helps with residual air.  Overall sounds pretty normal to me, so apply that clutch money to other mods!

BK

[kyle]

My 620 slips a little in 5th when the oil temp's under 60 deg celsius.. Once it heats up it's fine.. I though this was weird, but not sure?
Also my clutch engagement is quite early in the lever action, both before and after fitting asv shorties.

[Slide Panda]

I looked a little more closely at the aftermarket adjustable levers (which were installed by the PO) and it appeared they were holding the clutch actuator in just a very little bit all the time.  I put the original levers back on and bled the system, and now there is no slipping but the clutch still doesn't grab until it's let out damn-near all the way.

What year 620? If it's a year with the APTC clutch then that's normal. The ATPCs are knows for a pretty small friction zone that very far out in the levers travel

[Scooter Montgomery]

I had the same problem on my '03 620. I had the clutch springs replace with heavier ones, I think from an 800, been fine ever since.

[xsephirot]

Why not just back out the screw that the push rod goes into so you can still use your aftermarket levers.

[rule62]

The '04 has the APTC. The small friction zone at the end of the lever travel is par for the course. Not sure what's up with the aftermarket levers. I ditched the APTC on my '04 620 for a standard non-APTC wet clutch from an 800. Never looked back. I happen to think the APTC is crap. When it comes time to get new plates, do yourself a favor and just get a new standard clutch assembly. I got mine, plus a clutch plate pack for less $$$ than an OEM APTC clutch plate pack. And good luck finding aftermarket plates for the APTC if you happen to keep it.

[mmmpizza]

Wet clutch slippage is usually caused by (a) improper oil or non-ideal oil, or (b) improperly adjusted master cylinder actuator, especially after aftermarket levers are installed.  8.5k miles is pretty low for a wet clutch to wear out, but who knows how the PO rode it.  Late lever with short friction zone is typical for the aptc type wet clutches (came later than '04??).  Running an OE clutch slave?  Bleed the heck out of it?  Ziptie the lever overnight and see if that helps with residual air.  Overall sounds pretty normal to me, so apply that clutch money to other mods!

BK

Thanks,

What is APTC and how do I tell if I have it?  It's an '04.  If you're referring to it being a "slipper" clutch, from what I have read I believe that is what I have.  It's very smooth shifting, even when dumping the clutch.

[mmmpizza]

Why not just back out the screw that the push rod goes into so you can still use your aftermarket levers.

The PO had small hands and needed the adjustment, I don't so to me they serve no real purpose other than looking fancy.  Adjusting the nut out still did not give enough slack for the master cylinder to be fully disengaged, so... off they go! 

[Dirty Duc]

The '04 has the APTC. The small friction zone at the end of the lever travel is par for the course. Not sure what's up with the aftermarket levers. I ditched the APTC on my '04 620 for a standard non-APTC wet clutch from an 800. Never looked back. I happen to think the APTC is crap. When it comes time to get new plates, do yourself a favor and just get a new standard clutch assembly. I got mine, plus a clutch plate pack for less $$$ than an OEM APTC clutch plate pack. And good luck finding aftermarket plates for the APTC if you happen to keep it.

+1

Nice to know I'm not the only one on this bandwagon.

[Howie]

620 5 speed have conventional clutches, 6 speed have APTC clutches.

[mr.freezer]

howie... it is true?? I have monster 620, 2003, 5speed and I think i have APTC clutch.. When i shift down sometimes it feels like it slips and it sound not very good...

[DarkMonster620]

as far as I know, '05 + '06 620s&800s had APTC clutches . . . up to '04 5 & 6 speeds had conventional wet ones . . even part #s are different . . .

[rule62]

My '04 620 6-speed had an APTC. I know for sure because I looked at it, held it in my hands, and gave it away to a friend.

[DarkMonster620]

My '04 620 6-speed had an APTC. I know for sure because I looked at it, held it in my hands, and gave it away to a friend.

if VIN 4 as in '04 then was an early '05 but not all 6-speeds were APTC AFAIK and the info I've got from Ducati