Dare I say it.................oil

[ribbert]

This is a serious question, I repeat, a serious question!

Does anyone here have a standard (ie power) motor and standard clutch running on synthetic oil that they KNOW FOR A FACT does NOT slip above 6k rpm and WOT in the higher gears.

Noel

[Bob]

I've used Amsoil for years.  No problems. 
http://www.amsoil.com/shop/by-product/motor-oil/motorcycle/10w-40-advanced-synthetic-motorcycle-oil/

And here we go, another oil thread... 

[andyb]

A marginal clutch can and will slip with synthetic oil.  A healthy one will not.

The FJ clutch is marginal at best in stock form.  If it slips on synthetic, it's not the oil's fault, as it was getting ready to slip on conventional oil.

Do not use an Energy Conserving rated oil in a wet clutch.  Do not use aftermarket friction plates in your clutch.


I ran full synthetic in the FJ as an experiment to see if it'd make the shifting crisper.  (It didn't.)  In that state, it was dragraced and there was no measureable, unwanted slippage--but there was a coil spring conversion pressure plate, as the OEM setup was unable to hold with a mildly modified motor (stock cams, stock displacement) with conventional oil in it.  The slippage from that was mostly noticable at 6k and up in the longer gears; after putting more clamping force on the clutch pack, it felt very grabby for awhile, showing just how much it was slipping during routine use and going unnoticed.

So it depends a bit.  A wet clutch will have more of a chance to slip with synthetic than conventional oil, certainly, but a healthy clutch in any case will not.  

[FJmonkey]

You can also install a second clutch spring, many here have already done it with good results. Your original spring is not performing like new anymore, adding a second one will give you more spring force than OEM, so if the rest of the clutch is healthy then it should never slip.

[racerrad8]

I found that the oil used is irrelevant to a properly operational clutch.

If you have a stock clutch with a single spring and it is slipping then the quickest resolution is the double spring package or Barnett replacement.

If the spring is replaced with a new one and the friction plates are at the maximum thickness then the new spring will work well for some time. But if there is wear on the frictions the spring has less force clamping on it so it could slip.

The use of synthetic oil can amplify the underlying issue that you haven't fully experienced with conventional oil(s).

Randy - RPM

[andyb]

Hey!  I said that! 

[keand3]

Might be a bit off topic in regards to the oil question...

So when the time comes for me to change the clutch, should I go for the Barnett replacement? From what I understand this has been a debated topic at this forum..
Have read a bit on the topic. Some like adding springs other don't and some barnett mod.
Have seen several packages of friction plates for replacement of the FJ clutch at eBay and at RPM, but I miss a "package" at RPM that contains every product you need to either do the Barnett or regular replacement.
Makes it easier for a noob like me  

[racerrad8]

...but I miss a "package" at RPM that contains every product you need to either do the Barnett or regular replacement.
Makes it easier for a noob like me  

There are too many options for all of those packages...

If you have any questions just send me an email and I will send you everything you need in one "package".

Randy - RPM

[keand3]

...but I miss a "package" at RPM that contains every product you need to either do the Barnett or regular replacement.
Makes it easier for a noob like me  

There are too many options for all of those packages...

If you have any questions just send me an email and I will send you everything you need in one "package".

Randy - RPM

Thanks Randy!

Email will arrive shortly.

Ken

[craigo]

This is a serious question, I repeat, a serious question!

Does anyone here have a standard (ie power) motor and standard clutch running on synthetic oil that they KNOW FOR A FACT does NOT slip above 6k rpm and WOT in the higher gears.

Noel

Noel,

When I first switched to synthetic, I had experienced some clutch slip. It eventually went away the next time out for some unknown reason and works just fine now. My engine is bone stock.

CraigO

[bigbore2]

If you are using your bike for normal riding [commuting, road trips, the occasional rip-it-up just add another spring to the stock one already there and the 2  [i think]  new clutch fiber plates and forget about.The clutch mod write up is in the files section under clutch files. It is an easy mod- clutches are easy to work on. Yes there is also a wire to remove, but all is explained, in detail, in the mod.  I had 35,000 mi. on my clutch when I did the mod. and fiber plates were in very good condition. PO was easy on this bike. If you have not rebuilt your slave cylinder and master cylinder this would be good to do in addition to clutch mod.  I run Mobil 1 full synthetic. Stock engine.

[moonrunnah]

You can also install a second clutch spring, many here have already done it with good results. Your original spring is not performing like new anymore, adding a second one will give you more spring force than OEM, so if the rest of the clutch is healthy then it should never slip.

I have added a second spring last summer i bought from randy rpm because i had very slight slipping (not enough to justify for whole new clutch "kit")
i added the second spring and it made a big differnce hooks up real good 
how ever it is annoying when your in 90 deg F stop and go traffic (lots of extra pressure your holding back in the clutch lever

[oldktmdude]

You can also install a second clutch spring, many here have already done it with good results. Your original spring is not performing like new anymore, adding a second one will give you more spring force than OEM, so if the rest of the clutch is healthy then it should never slip.

I have added a second spring last summer i bought from randy rpm because i had very slight slipping (not enough to justify for whole new clutch "kit")
i added the second spring and it made a big differnce hooks up real good 
how ever it is annoying when your in 90 deg F stop and go traffic (lots of extra pressure your holding back in the clutch lever

Hence the recommended use of a 14mm clutch master cylinder.   

[ribbert]

Thanks for all the contributors to my clutch question.

I'm aware of the clutch mods but I don't want to increase the pull at the lever.

The reason I asked the question was to try and home in on my clutch problem.

My clutch performed faultlessly even under the most extreme conditions, that being a 4th to 5th change at redline, there was no slip, not even a little bit of feed in, it would bite instantly.

Then I changed to synthetic and it slipped. I went back to my old oil and it improved after a while, I replaced the clutch spring and it improved a bit more.

I pulled the clutch this week and the fibres are 3.0mm and the steels still have the machining marks on them, I am not hard on clutches and it has never been allowed to continue slipping once it lets go.

I don't see why you should need to add extra springs etc to the clutch if you have replaced the spring and the plates are spec. The plates in there are the same thickness to the micron as the new plates I bought this week and if the clutch worked fine for the first 80,000k why shouldn't replacing the wear components return it to a serviceable condition?

What's worse is the last oil change with synth, I drained it from one bike and poured it straight into the other, and now that one slips too.

I'm a stubborn bastard and on principle I don't want to add an extra spring just to make it work like it did for 20 years without one.

[movenon]

That's interesting. Once that oil gets soaked into your clutches it might take a awhile to get back to normal.
I have a positive track rear end (wet clutches) in my truck. I converted to synthetic oil and it it didn't work out to well, in the end I went back to what the factory said to use and after a few hundred miles things got back to normal. 
George