slipping clutch

[Parminio]

I was talking about the OP.

 

[ouchez]

I always use Valvoline Motorcycle oil "safe for wet clutches".

 

[user 16790]

ok I have fitted some new friction plates, the middle six and left the others as were, I have also taken out the Motul 5000 10w40 and replaced with Silkolene 10w40 which is what I had in the bike before the slipping started, I have given the bike a good ride and there is no more clutch slip so I'm happy,
my son came around and used his vernier thingy to measure the plates that I took out and they were all in the region of 3.05mm, as that dimension is still within spec I think it must have been the oil that made it slip,
my clutch spring measured 6.5mm in height so that is also still in spec,
I now have some very slightly used Motul 5000 10w40 weed killer
thank you to all for advice and help

 

[Pighuntingpuppy]

I have had people adamantly tell me that nearly all engine oils can be used for wet clutch systems in motorcycles. My Virago....not a huge horsepower bike at all....would slip if the wrong oil was in it. If the engine oil in my Virago was not wet clutch safe....it slipped. Because I know the value of quality lubricants, Even my Virago got Yamalube.

 

[MaxMidnight]

I have had people adamantly tell me that nearly all engine oils can be used for wet clutch systems in motorcycles.

Hmm, not sure that I would go along with that particularly oils that are low viscosity (e.g. 5W-20 or even 0W-8) and have friction modifiers (i.e. has the 'Energy conserving' label).
Additionally as the oil in many motorcycles is also used to lubricate the gearbox consideration has to be given to this as well.

 

[Pighuntingpuppy]

Hmm, not sure that I would go along with that particularly oils that are low viscosity (e.g. 5W-20 or even 0W-8) and have friction modifiers (i.e. has the 'Energy conserving' label).
Additionally as the oil in many motorcycles is also used to lubricate the gearbox consideration has to be given to this as well.

Some people just dont know what they are talking about. And thats the thing with motorcycle oils. They resist shearing and aeration. Another factor alot of people who think they know something, never bring up.

My one pickup truck runs timing gears with a flat tappet cam. Finding the correct zinc level in an oil that also resists shearing and aeration was tough. Castrol 5W50 full synthetic as per Castrol themselves stated that its a classic car formulation with high zinc(over 1300 ppm) and excellent properties against shearing and aeration. That engine runs 60 psi cold at 25 psi hot at idle. Was a dedicated runner up until 2 years ago when I decided to start making it solid axle 4x4. It still starts and runs. Just no rear axle at the moment, LOL.

 

[Fire-medic]

ZDDP is what wet clutches need, formulations for newer cars doesn't have that, not at the concentrations needed for wet clutches and old motorcycles with unit construction. Motorcycle oils are supposed to have more ZDDP because the crankcase and gearbox/clutches run the same oil. Oil for a Honda Civic is not oil for a Honda CBR1000RR.

 

[user 16790]

I don't know anything about oils other than they're slippery substances so I'll just stay with brands and grades I know to be ok from now on,
the only time I've had a clutch slip before because of oil was when I mistakenly used a fully synthetic oil in my TDM900 instead of a semi synthetic, so it surprised me that two different brands of the same rating and type of oil could cause such symptoms in my Vmax,

ps. my metal plates had blued streaks around them but all the dimples were unworn in appearance and they still work ok, if I get problems again I'll fit an extra spring and try that, but so far it is good

 

[sdt354]

I don't know anything about oils other than they're slippery substances so I'll just stay with brands and grades I know to be ok from now on,
the only time I've had a clutch slip before because of oil was when I mistakenly used a fully synthetic oil in my TDM900 instead of a semi synthetic, so it surprised me that two different brands of the same rating and type of oil could cause such symptoms in my Vmax,

ps. my metal plates had blued streaks around them but all the dimples were unworn in appearance and they still work ok, if I get problems again I'll fit an extra spring and try that, but so far it is good

An extra spring just about guarantees no slippage. That's how I roll. But, I admit the bike I work on has a spring upgrade and it works just as well, minus the heavy lever pull.

 

[user 16790]

what is the spring upgrade you talk of

 

[Parminio]

If all else fails, consult the owners manual.

 

[Fire-medic]

The two spring upgrades most people choose between:

Barnett multiple-spring faceplate

PCW heavy-duty diaphragm spring

The Barnett faceplate is more-expensive than the PCW Racing/Schenectady NY replacement diaphragm spring.

Barnett Coil Spring Conversion Kit
Part# 511-90-10002
MSRP $152.60
Notes:
Fits V-Max (thru '07), XVZ Road/Royal Star, and Road Star models. Converts stock diagphragm spring to six heavy duty coil springs for a more progressive, controllable engagement. Includes billet pressure plate, springs, and screws. An optional extra heavy duty spring set is also available- #501-82-06023
https://www.barnettclutches.com/1311/yamaha/0/0/2007-yamaha-vmx12-v-max.html
PCW Racing
Address: 112 Henry St, Schenectady, NY 12304
Phone: (518) 346-7203

They don't have a web presence. Phone them. They sell a heavy-duty diaphragm spring, a clutch cover gasket, and a full-width OEM friction disc, in a kit. The friction disc replaces the half-width innermost friction disc and the spring-steel wire which sits inside the half-width OEM friction disc, acting as a slipper clutch to ease downshifts. Call them for current pricing.

 

[user 16790]

thanks, unfortunately it's too expensive to buy things from USA because of the import charges to the UK but obviously I would if it was my only option,
I went for a 130 mile ride yesterday and experienced no slip at all so I think it is good for now

 

[85vmax]

The two spring upgrades most people choose between:

Barnett multiple-spring faceplate

PCW heavy-duty diaphragm spring

The Barnett faceplate is more-expensive than the PCW Racing/Schenectady NY replacement diaphragm spring.

Barnett Coil Spring Conversion Kit
Part# 511-90-10002
MSRP $152.60
Notes:
Fits V-Max (thru '07), XVZ Road/Royal Star, and Road Star models. Converts stock diagphragm spring to six heavy duty coil springs for a more progressive, controllable engagement. Includes billet pressure plate, springs, and screws. An optional extra heavy duty spring set is also available- #501-82-06023
https://www.barnettclutches.com/1311/yamaha/0/0/2007-yamaha-vmx12-v-max.html
PCW Racing
Address: 112 Henry St, Schenectady, NY 12304
Phone: (518) 346-7203

They don't have a web presence. Phone them. They sell a heavy-duty diaphragm spring, a clutch cover gasket, and a full-width OEM friction disc, in a kit. The friction disc replaces the half-width innermost friction disc and the spring-steel wire which sits inside the half-width OEM friction disc, acting as a slipper clutch to ease downshifts. Call them for current pricing.

Nobody does the double d...DD....anymore?

 

[Fire-medic]

Sure they do, but that can be hard on arthritic hands.