Went on a rip this weekend and noticed that my clutch started to slipp in the higher rpms. Just started after i changed my oil to Elf semi 10w40 mot oil. Just wondering what you guys are using and has this ever happend top you. Ive heard diffrent oils do diffrent things to a clutch. Didnt do it when i put castrol 10w40 in but I kinda wanted to go with a semi oil? is it needed?

 

i've heard on more than one occasion from mechanics that if a set of plates has been bathed in synthetic oil that it has to keep using synthetic oil and cannot revert to semi-syn. however, if the plates were run in semi-syn, that it is okay to go to full syn but not vice versa.

i don't know if this is true or not as i have never tried it. i just keep using semi-syn and have never had a clutch problem.

 

My buddy's Blackbird was doing that. He replaced his clutch and it was fine. You should stick with one type of oil. Switching messes up the clutch material.

 

The clutch is new (from what i was told) besides it doesnt feel warn

 

it's not that the plates are worn. it's the fact that the oil that has sublimated the plates is affecting the performance of them.

 

looks like i'm going to replace the clutch in mine after reading this. i picked up a real 'gem' that's had all kinds of gremlins.. first off it has a V+H exhaust and upon examining the carbs found 105 jets! no wonder it was petering out in the high revvs! i bunged some 130s in there and now the thing's screamin' up + down the road. my problem now is the clutch slipping like a banana peel when i give it the beans in high gears.

it goes through 1st, 2nd pretty good but towards the top of 3rd, through 4th+5th it's slipping and revving up to red line then finally settles back down and catches.

i was going to do an oil change but i might as well do the whole clutch - i wouldn't put it passed the guy i got it from to have been running automobile oil in it. i've found some EBC clutch plates + springs on oldbikebarn.com - thing is, they have two sets of springs that have the same description - 10% stiffer than stock. anyone know if there's any difference between the two sets of springs offered for '87 CBR600s ?

thanks,
chris

 

Welcome to the board! Nice thread revival Not sure about the 600 springs but I have been forced to use heavy duty labeled springs in high HP apps. The clutch pull went to crap ... as in o.k. going through the gears but get stuck in traffic for 30 minutes and left hand was dying. Unless I need stiffer springs I tend to stick to stock now.

 

it might have had regular oil in it.. some mechanics have told me, when you put synthetic in a old engine. It cleans away all the debree and build up.. which cause things like gaskets to leak etc.. maybe it's the same with the clutch?

 

my plan is to set this baby up for track use so i'll prolly go with the stiffer springs. i hear ya with the "dead hand" syndrome in traffic, i have an '83 CB1100F with heavy clutch and wow, just light-to-light kills me (in southern CA - that's just about all the riding you get anymore)

i'm going to just do the whole clutch, springs+all. do you just order a new nut from Honda to replace the "staked" one in there or can you match something from the local hardware?

oh yeah, and the airscrews - i have them set backed out 2 1/4 (CA settings)turns as suggested in the manual but since i have up'd the jets from 105 to 130, should i do anything about leaning it with the airscrews? it's still running stock airbox+filter.

cheers,
chris
ps. thanks for the welcome!

 

What you should be doing is buying yourself a decent Carb kit and doing a proper carb tuning procedure if youre planing on racing at the track. Get yourself a factory pro kit, tuning procedure is included with their kit.

Now you are correct you would adjust the final mixture with the air fuel adjustment screws, but doing so will mess with your off idle throttle response. So in this case this is what you should be doing.

You say you put in a 130 Main? This may actually be too big anyway, yes you may be getting more torque at higher rpm's, but I bet if you dropped to a 124 you'd notice it has better than the 130.
(130 Keihin is equal to a 122 Dynojet which is recommended for an airbox mod and K&N Filter)
You should always start with about a 118 and then test ride each main jet until you get one that pulls the hardest between 7000 and redline (Consistantly meaning cold and at operating temperature) If you find it pulls great when cold and less when hot, your main jet is too large. Do NOT move on to step 2 until you have the best main jet selected.

Second, if youre not going with a kit, remove the fuel needles from the diaphrams, and go to the local hardware and see if you can match up some washers that are the same size as the stock spacer on the needle (In thickness as well as width). Add 1 spacer at a time and then test ride for about 15 minutes. Install no more than 3 on each fuel needle, this will give you a richer mixture bewteen 4000 and 7000 rpm. And when you find one that seems to give the best pull from a 2nd gear throttle snap from 4000 rpm, stick with that.
Do not move on to float height until this is perfect.

Next you need to adjust your float height. Factory setting is 8mm so dont go any higher than that as usually that doesnt let any fuel in the carbs at all. If you're going richer, adjust it down to about 6mm or 7mm, you want the setting that pulls the best between idle and 4000rpm. Dont play with the mixture screws until this is done.

After this is done set the fuel screws at 2.5 turns out, at idle of 1000 RPM blip the throttle and see what the rpm's do if they jump up and "hang" for a second before dropping down, your idle is too lean, adjust the screws out 1/4 turns until it just jumps up and goes back down to set idle speed with no hanging. If the idle goes up when you blip the throttle and then drops down BELOW your set idle speed for a second then goes back to 1000, your idle is set too rich and you want to turn the adjustments IN 1/4 turns until this smooths out. Odds are after doing the above steps, it may be set too rich if you do not mod the airbox or install a K&N filter.



For your clutch, it may be the oil, or maybe the springs are worn. before changing the plates and fibres, just pull the old ones out and check them for overheating. if no signs of bluing are present, just clean them up with brake clean and soak them them in your semi oil and reinstall. If you want to stiffen your springs, the oldschool track guys used to put a washer above each spring to stiffen it up.