Clutch Slipping On Kickstart After Oil Change?

Discussion in 'Vintage Classics' started by Shabuti, Nov 4, 2024.

  1. Shabuti

    Shabuti Well-Known Member

    Dec 27, 2022
    34
    68
    USA
    So I decided to replace my primary chaincase gasket on my 1969 T100. I need to replace all the major lower engine gaskets so I started with this one. After taking it off, appears as if someone previous had used some "make a gasket" tube crap that I had to scrape off both parts that took forever.

    Everything inside the primary looked almost brand new, no idea service history on this bike but this is my first time removing the primary cover and Iv put probably around 1000 miles on it since Iv had it.

    I literally didnt touch anything except for the chain tensioner, which I had set to around 1/2 inch play as the book stated. Now, the books I have state an oil capacity for the chaincase which to me implied that I needed to add oil to it after putting it together. I thought the book asked for 30 weight, so I put some in didnt have quite enough so I added a bit of 20 weight I had laying around. Both car oils, as the book did not specify otherwise. But, I realize in the 1960s they didnt have the kind of oils we have today...

    So anyway, now the kickstart wont hardly turn the motor. It has a constant resistance, and every now and then it will turn the motor over one revolution then nothing. I did some research, and it suggest that my clutch is slipping, most likely due to the oil I used.

    So I drained as much of the oil out of the primary AND engine as I could, using the drain ports and a pump to get as much out as possible. Refilled the engine oil with lucas oil thats rated for wet clutches, didnt put any in the primary and went to kick it and its still not doing anything after about a few hundred kicks.

    I never had a problem with my kickstart until now. And the more I have read, my clutch may have been slipping the whole time because in top gear if I give it alot of throttle I get more empty revs than speed gain so I have to accelerate relatively slowly in top gear. But Iv never put the proper oil in the bike I guess until now.

    Do I need to take apart my clutch? What do I do now? Should also be stated that my clutch cable is a little tighter now, I slacked it a bit at the handle but its definately different. I dont really know how else to adjust it, but the bike seems to shift and clutch seems to work fine when the bike is running, but takes about a million kicks to get it started now.
     
    • Useful Useful x 1
  2. joe mc donald

    Subscriber

    Dec 26, 2014
    14,420
    1,000
    slough / burnham
    @Shabuti Yes you may need a new set of friction plates. While there check the metal driving plates. If they are within tolerance clean and rough them with some emery paper. I can't remember how much you put in the primary case but its not a lot just enough to splash on the drive chain. Some of the knowledgeable people will i am sure answer that for you. On all my old bikes i used to just use Duckham's 20/50 including the primary. And gear box 80/90
     
  3. Baza

    Baza Elite Member

    Jul 25, 2020
    3,418
    750
    Amazing Grace
    I would have thought that removing the clutch plates and thoroughly cleaning with brake cleaner would have done the job. However I suspect proper adjustment, spring tensioning is playing a part here.
     
    • Agree Agree x 1
  4. Shabuti

    Shabuti Well-Known Member

    Dec 27, 2022
    34
    68
    USA
    How can I adjust it? My book isnt very descriptive on that part. I dont have to take the primary off again to adjust it do I?

    I would do literally anything to not take the clutch apart haha. I can do engines all day, but when it comes to a clutch they are mostly a mystery to me haha.
     
    • Agree Agree x 1
  5. joe mc donald

    Subscriber

    Dec 26, 2014
    14,420
    1,000
    slough / burnham
    @Shabuti Yes if that doesn't work you will have to get the cover of clean all the plates and test with a vernier to make sure they are within the specs and width you should have a three or four spring clutch just turn the springs in half a turn at a time keeping them even. You may also have to change the springs as eventually they do weaken. And these days you can get stronger springs. Its all trial and error.
     
  6. Shabuti

    Shabuti Well-Known Member

    Dec 27, 2022
    34
    68
    USA
    Ok. Well, I guess Im gonna try a few other things and if comes down to it Ill just go ahead and replace everything with the clutch that way its all done at once and hopefully I wont have to touch it again after that.

    The bike indicates only 4400 miles, and the odometer does appear to be working and its definately the original gauge haha. But I guess I dont know how its been treated
     
    • Agree Agree x 1
  7. Iceman

    Iceman Crème de la Crème

    Apr 19, 2020
    2,391
    1,000
    Lancashire
    Firstly remove the clutch plates, clean up the friction plates with brake and clutch cleaner (or similar), clean up the plain plates and then re install the clutch, check the springs for uniformity and the correct length, if they are in tolerance then tighten up the clutch springs again to tolerance, and a nice pull action at the lever, then remove the spark plugs, this will allow you to turn the Kickstarter by hand, you then spin the engine over whilst looking at the clutch pressure plate, you will see the clutch running uneven, you adjust each of the clutch spring nuts a little at a time until the clutch runs true. The clutch runs dry, the chain case oil is only there to lubricate the chain itself, so I would advise using ATF fluid so it just touches the lower chain run, use a proper gasket and no need to use any sort of gasket sealant, it only cause issues, a little light grease will hold the gasket in place. Re fit the plugs and plug leads and start it up, it should kick over smoothly and when running, smooth gearchanges and a light clutch pull. Ride safe all from an ageing Rocker.
     
    • Like Like x 1
  8. joe mc donald

    Subscriber

    Dec 26, 2014
    14,420
    1,000
    slough / burnham
    @Shabuti Mate at those miles you should be fine. You may just have to clean and reinstall. When you do if you do strip the clutch just smooth the plates were the fit into the drum if they have indents in them but I should think yours are still like new. But there are peeps on here like @Iceman and @darkman who know your bike inside out and i am sure they would be there to help with any advice you need so just get stuck in there.
     
    • Like Like x 1
  9. sprintdave

    sprintdave Nurse, think it's time for his medications.
    Subscriber

    May 25, 2014
    1,548
    750
    Birmingham
    All good advise above but also you should have a 2 to 3mm free play at the clutch lever as this can cause slip.
    With the clutch outer cover off and as stated , spark plugs removed, clean and degrease the clutch plates and check they are all in there, it has been known. Check spring lengths are in spec, if not, replace. Tighten the springs evenly , you may find they need tightening more than they were before, and using the kick-start turn the engine and adjust the springs till the clutch runs with no wobbles. Cover back on, add recommended oil, may be atf , do not overfill.
    Adjust clutch lever with slack. Ride.
     
    • Agree Agree x 2
  10. darkman

    darkman Crème de la Crème

    Oct 26, 2015
    7,633
    1,000
    Southcoast of the UK Earth
    When adjusting clutch play you slacken off the adjuster at the handlebars first, then remove the inspection/adjuster bung on the primary cover by the left foot peg. Inside there is a 9/16 lock nut with an adjuster screw, slacken the nut and adjust the screw out and then back in till you feel it just nip up on the pushrod, then back the screw out a 1/4 of a turn and tighten the lock nut, this gives you free play at the clutch, then adjust the lever on the bars so you have 1/8th play.
     
    • Agree Agree x 2
    • Like Like x 1
  11. joe mc donald

    Subscriber

    Dec 26, 2014
    14,420
    1,000
    slough / burnham
    @darkman I knew you would be here to the rescue.
     
    • Like Like x 1
Loading...

Share This Page