Topic: Cb550 clutch slipping under WOT 1st-2nd

[RFogelsong]

So my friend just got a cb550 just like mine only his is a 74 and we swapped while riding the other day.  I noticed that when really getting on the bike after shifting into second gear and pinning the throttle the RPM slowly goes down to where it should be in second gear instead of being instantly engaged, almost as if I'm manually slipping the clutch through the friction zone while giving the bike power. 

It doesn't do this in any other gear and has a strong take up (you can feel when it fully kicks in when starting from stopped about 3/4 of the travel on the lever).  His friction zone is right in the middle as it should be and I checked his cable for binding. The marks on the casing were also matched up.

My guess is the clutch is starting to go, but I'm hesitant to say that because it's only in one gear under one condition (moderate throttle is fine).  Could oil cause this? Could it be a gummed up linkage on the case? 

   

[dave500]

if you havent already change the oil,then check the adjustment and the cable is lubed or free to move,the case linkage wont gum up.

[Rgconner]

Heh. I am about repeat myself...

if someone put oil in it that has "slip modifiers" then it will feel like that.

If you don't know what is in it, try changing the oil to a 10-30 Rotella or Mobile Delvac. Available by the gallon for less than $15.

If not.. well it is an easy enough job. Getting the screws off can be a bugger, get a impact driver if you don't have one, and if possible, replace the JIP screws with hex/allen ones.

Kits are available from fellow SOHC4 members.

[Danno]

usually if the bike has 20k or less on it someone has put the wrong oil in it my 74 works best on regular castrol 10/40 it will slip if you put others in it althought the oils listed by RG will work also
absolutely do not put synthetic oil in it the clutch will slip it was not meant for that kind of oil the clutch would have to be put in backwards with stronger springs to use synthetic

if you have regular oil in it and it is still slipping after your second change then the springs in the clutch have gotten weak but I doubt it

[Rgconner]

Definitely worth the cost of new springs if u gotta do the clutch.

[TwoTired]

absolutely do not put synthetic oil in it the clutch will slip it was not meant for that kind of oil the clutch would have to be put in backwards with stronger springs to use synthetic

I've been using synthetic (Honda HP-4) in my stock 550's for 15-20 years.  The clutches don't slip.
It not about "synthetic", it's about the additive package blended with the oil base stock, whether it be crude based, or made from assembled hydrocarbon molecules.

Cheers,

[RFogelsong]

I thought this might turn into an oil thread.  I told him about how there's moly in newer high efficiency oils and all that, and we'll probably change oil in both our bikes before riding much more, if any (20 degrees F here today), I just figure there's no reason to let new oil soak up moisture over winter. 

It just confused me that it only did it under one condition in one gear.  The cable definitely isn't binding.  I'm half trying to buy it off of him because that is literally the only thing wrong with the whole bike and he got it for a steal (middle of winter and all).  I'll let you know how it goes. Oh, and the bike's only got 6K miles on it. My bet's on high eff. oil about 1 cycle ago.

[Rgconner]

Even if it is shot, worst case is new clutch+plates+springs and some elbow grease. Usually the plates are reusable, I had to replace 2 slightly warped ones on my engine with 27K on it.

$100 tops if you can get the bike, not a bad deal.

Oh, and +1 on the synth. It is not the synth that is the problem, it is that they load it up with modifiers to justify the price.

Amsoil makes a synth that works great in these bikes. Problem is, with a ~1500 oil change cycle, it is a bit expensive.