Clutch Slipping issue

[Bronxboy]

I have an intermittent slippage if that is possible? Fluids were flushed not to long ago, clutch fluid was a little low but I am sure not the issue. Clutch lever real smooth as normal, no metal particles in last oil change. Seems to randomly slip on take off in second and third gears? Sometimes I can go hard thru the gears and no issue?

Could a bad slave cylinder be the culprit and not the clutch assembly itself? I have 107K miles on the bike. All the splines and final drive are all in great shape so I know the issue is not coming from there?

Any thought will be helpful, I am going to re flush the clutch and go from there.

[gordonv]

Could it be from a weak shift? Did you change your foot gear recently?

I know a weak shift can pop out of gear, but sometimes I have felt a slip too. When I go from soft shoes to my work steel toed boots, I can shift a little lighter.

[Bronxboy]

No it happens while already in gear, u can feel the bike rev up and slip, then grab. Does not happen all the time, but more frequently now.

[98valk]

that's the rear tire losing traction from all the power.  

possible real issues,

slave cylinder, only way to completely flush it out, is to remove and clean.

what oil are you using? oil as have really changed their formulations lately due to new standards.

Goldwing GL1500 forums, many do an engine flush after 100k miles, due to slippage. However I tend to remember it was units built before '97 which had mixed clutch plates. '97 and newer, this includes Valkyrie all have the same better clutch plates and don't have this problem.

what we don't want to hear, the damper plate is starting to go bad.

[Jess from VA]

I've been having the same very intermittent issue for several years.  Seemed to only happen soon after startup (not fully warmed up) (and esp. if honking on it in low gears) (after warmed up, never happens again).  But last time, it got worse.  So now I'm riding the other bike, and plan to have my guy look at it during winter slow time. 

Good fresh Mobil one (no friction modifiers), full clutch flush only 5K or so ago, nice and clear in the sight glass) (no leaks).

I'm thinking slave too (only 55-60K; '99 Interstate).  Or sheared rivets.  It's a mystery. 

[Tfrank59]

Normally a clutch that's slipping due to wear on the friction plates is going to happen in the higher gears not the lower. Slippage in other cases might be caused by something else like maybe the throw out? On my other bike when I put in full synthetic even though it was compatible for a motorcycle with a wet clutch it changed and started slipping in the higher gears and I ended up changing the clutch plates which fixed it

[bikerboy1951]

Check the pressure relief opening in the master cylinder.  It is located under the little duck bill.  If there is junk in it it will cause slipping.  Acetylene torch tip cleaners work well for cleaning it.  It will cause no damage as there is nothing below it until you pull the clutch lever in.

Brad

[Bronxboy]

Thanks for all the replies 

[97BLKVALK]

Check the pressure relief opening in the master cylinder.  It is located under the little duck bill.  If there is junk in it it will cause slipping.  Acetylene torch tip cleaners work well for cleaning it.  It will cause no damage as there is nothing below it until you pull the clutch lever in.

Brad