Oil change and now clutch slips

1976 360 WR. I changed the oil and now I can't push start the bike because the clutch slips. I put in Mobil 1 4T 10w-40. Everything was fine before the oil change. I have to push start because I simply can't kick start the bike when cold. Do I have to take the clutch apart and clean everything or maybe run Type F ATF thru it? Suggestions.

That bike isn't primary kick so the pushing it vs kicking it would be the same wouldn't they? A slipping clutch does make for hard starting on those, been so long and I never did anything but kick.

Generally speaking the oils with the energy conserving in the bottom of the circle thing are to be avoided. I thought it was sticking more than slipping though. I have been using the red cap Mobil 1 15-50 in the 510 four stroke. It doesn't have any writing where the energy conserving is in the lighter mobil one produts currently available. I havn't seen any red cap bottles for a few years though. It works wonderful for me.

I use hy guard from John Deere in all my dirt bikes that are pre mix on the engine. If the plates aren't being held apart mechanically or all slack out of the rod that pushes on the clutch I would think you have to wash or replace them. Don't use lacquer thinner.

I find it hard to believe just changing the oil would have an immediate effect though the product you used is most likely a newer released one.

fran

I only use Bel ray gear saver 80w in my 75 360 and 80s bikes, would like to try the hy-guard some day.

I am no clutch expert by any means, but how do you know its slipping if you have not started the bike. Try draining that oil and add different oil. I am having a issue with my clutch sticking when I go to start it and I changed to hydraulic fluid (32) and it helped a lot . I am going to clean the plates next and see if it will cure it. Your bike should start on 3 or 4 kicks tops , if it don't you have carb issue's or spark issue's or a bad kill button (sticking or grounding out on something when your trying to kick start). Unless you have a bad foot you should be able to kick start any bike that has a kick start lever. I know it's not the answer you were looking for I am just trying to help.

Ive been using Shell Rotella T 15-40 in my 78-CR250 and my 2007 WR167 w/autoclutch with no slippage for a few years. Cheap and readily available at W/mart.

Thanks for all the suggestions. Yes I've got a bad knee, low spark and it starts fine once warmed up. I know its slipping because when my son pushes me down the drive it doesnt turn over or start. Can I just run some kerosene or mineral spirits thru the tranny and refill?

You could try it , I used brake cleaner before and it did flush alot of sparkly crap out the bottom ... make sure you tie or have some one else hold the clutch lever in so the fluid washes between the plates maybe even gently pry them apart with a small screw driver and then pour or spray . I like the brake cleaner, it has a lot of pressure to spray the garbage out. good luck.

If you have been in there recently and know there isn't any caked crud and you have the sureflex type not the barnett type with only four slots per friction disc perhaps. You really have to take that cover off to make sure the clutch push rod is adjusted properly. The springs themselves may not be like new either. Valve springs in a four stroke of that era have been lesss than spec in my experience.

I would suggest taking the cover off washing them in hot soapy water and trying to get an idea if the whole stack is shorter than it ought to be. You can see how much metal chips are laying around as well.

A friction modified type engine oil will cause the clutch to slip as it coats Teflon modifiers everywhere. Put a couple of litres of kero or fuel in there, kick it over with the clutch in (don't start it!!) then drain and refill with ATF - F and all should be good!

If you still have issues, you will need to take Fran..k's advice and pop the cover and check the clutch play rod hasn't wound itself on. if you disconnect the cable you should have some freeplay at the case lever.

If you pull the clutch apart, a light rub with wet and dry of both fibre and steel plates after a scrub in fuel should scuff them up ok (unless they are totalled!)

good luck

Thank You Suprize. I'll try it but just in case have ordered new clutch steels and friction plates. If I'm diving in that far I'll change them.

I was told to not use synthetic oil in the vintage bikes because of the problems you are currently experiencing. So I use the cheapest multi-grade oil I can find and don't have clutch slip. It's not that much trouble to pull the clutch out and wash the material disks in solvent and reinstall. The torque on the clutch spring bolts is 44 inch pounds so don't over tighten.

Ty and I read your thread this morning and found it interesting. Mobil 1 4T 10w-40 is Jaso Ma rated and has no friction modifiers. Ty suggests to pull the clutch apart and place a dial caliper on the plates to see if they are still in specification. The fresh oil may of been thinner than the old and float the worn plates just enough to cause the slippage.

do not use synthetic oil in the older bikes.. Period...
may need to clean your clutch plates...

It isn't that simple. While I don't understand what makes something synthetic as it is all derived from crude oil or maybe plant oil, there are all sorts of synthetic oil products out there. It is probably the additive package not the oil itself that causes problems in clutches.

Honest I bought my 1988 te 510 (same clutch and transmission right?) in 1997, have replaced the cam chain twice, at least a few tires and chains, but never washed or replaced any clutch components using 1997 era red cap mobil 1.

Mineral oil is created using distillation from crude, synthetic uses multiple completely pure products mixed together to form an oil product.

10W40 has a viscosity of like 108 when cold and I don't know the particulars of what happened with the clutch, but it would of had to of been ran for quite a while to not only infiltrate the clutch disks, but coat them with some mysterious friction modifier. From the posting it looked like the oil was poured in and instantly started slipping. This just seems rather odd to me.

Sounds like lack of free play in the clutch cable, or clutch push rod doesn't have enough free play.
Later George

Tinken is right, synthetic has nothing to do with it, its the friction modifiers (if any) that cause the problem, and ALL car specific multi grade oils have them. The Mobile 1 4T should be fine, its made for wet clutches in bikes. I agree with George that you likely have another problem, lack of cable free play or more likely the pressure plate adjustment needs to be set.

Thanks I will check the free play. My point was it worked fine until the oil change with no other changes. I ordered new plates and will rebuild the clutch and adjust the free play. What oil should I use?

My family owns nine vintage Huskys from as early as 1960 and most of those use Amsoil synthetic because the owner prefers that brand. I have had great experiences with 0W-## oils because they give the performance of ATF with the protection of motor oils.

Hi Mick K,

Does your 76 Husky have aluminum friction discs in the clutch?

If it does separate the clutch plates and friction discs, now with your pile of friction discs pinch the left side of the stack with your left thumb and index finger, 180 degrees opposite pinch the stack with your right thumb and index finger, if you can see any air gap between the friction discs they are worn out.

Bill502 is right use a cheap multi grade oil, non friction modified, I have always used 15w-40 or 20w-50 any oil that is suitable for both petrol and diesel engines won't have friction modifiers.

I tried to upload a Husqvarna Service Bulletin but it won't upload for some reason, but it says to use Hypoy B 80w-90 EP, GL5 or Castrol GTX 20w-50.

Cheers,
DaveM.