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Oil Leaks - 1978 XS Special

Discussion in 'The Garage' started by Backroader, Feb 2, 2010.

  1. Backroader

    Backroader XS650 Addict

    Well I started cleaning up my new ride and found oil leaks, some still weeping, others hardened over time.

    I as I contiue to clean the engine I am sure I will have more questions....here goes:

    1. Looks like the tach cable at the engine is one of the culprits . Is that a simple oil ring fix ?

    2. Valve cover may have leaked enough to spill out around the exhaust and head gasket. Assume it's a gasket replacement only.


    3. Oil drain plug area was wet, waiting to see what happens after I dried the area off a bit.

    This is starting to be fun...never had 650 before..only the 750. Can't wait to get at changing the oil....sounds like a lower end motor job.:laugh:

  2. yamaman

    yamaman xs650 addict

    Often a neglected XS will leak oil at the head gasket. Some have solved this simply by re torquing the head. Never know till you give it a go!
  3. inxs

    inxs xx

    - when first starting her up watch those 3 left side case seals..push rod, gearbox-behind sprocket and crank-behind the alternator, they may have hardened somewhat
  4. The Tach Cable Adapter has 2 seals, an O-Ring on the outside of the Tach Gear Housing, to seal between the housing and the case and an Oil Seal inside the housing, to seal the rotating gear. Try to determine if the oil is coming from between the housing and case or from inside the housing. Both are easy to deal with. Remove the tach cable; then remove the screw threaded into the case that locks the housing in place and withdraw the housing. There's your o-ring. The oil seal is inside the housing under the threaded cable adapter. Unscrew the cable adapter from the housing and there's your oil seal.

    Try as Yamaman suggested and re-torque the cylinder head nuts before resorting to removal of the engine to replace the cylinder base and head gaskets. If you do end up replacing these gaskets, consider replacing the stock steel/rubber head washers with copper ones to provide a more even torque load to the head. In fact, consider fitting these even if you do not end up replacing the gaskets. They can be easily fitted and also provide a great seal against oil leaks.

    The areas INXS pointed out are common leakage areas to watch and address, if necessary. If you replace the clutch pushrod seal, check the bushing there for excessive wear and replace, if necessary. This can all be done without removing and splitting the engine, but care is necessary when doing it. Also consider a one-piece push rod here to reduce wear of the bushing and resultant oil leaks. If the seal leaks behind the sprocket, there is a kit available to allow you to replace this seal without engine removal.

    Have Fun!

    Attached Files:

    peanut likes this.
  5. weekendrider

    weekendrider Iron Horse cowboy Top Contributor

    S.W. MO
    Some of the valve covers use gaskets, some have o-rings. To me the o-ring tends leak more. Watch the torque going back on. It's easy to strip out the bolt hole on the head.

    The primary sprocket is notorious for being loose, with some finding them only hand tight. Worth checking right off. Re-torque cures the leak 90% of the time.

    Unless the pushrod seal is puddling (as opposed to dripping) the dire necessity of changing isn't eminent, unless it's a green or clean thing for you.
    I thought of one as an automatic chain oiler for 2 years.

    The solid metal(brass,copper) head washer swap is a good mod. But again not a ride it or not thing. Re-torque what you got even if it isn't leaking yet.

    It could be the PO couldn't find a new copper washer for the drain plug and tried a substitute. Usually the new owners find they can't get them loose. Not that they weep/leak.
  6. inxs

    inxs xx

    - installing a brake booster check valve in the crankcase breather line helps create negative crankcase pressure and serves to restrict leaking oil seals...early models have 2 lines, later models 1

    - most good auto parts shops should have these valves

    - crankcase breathers-found at the back of the head

  7. retiredgentleman

    retiredgentleman XS650 Guru Top Contributor

    When replacing the oil seal and o-ring on the tach drive, be careful not to lift the shaft itself. If you lift the shaft, the shim at the bottom of the shaft will fall out into the bottom of the primary case. When I had my primary case off, the shim on my tach drive was missing (damn PO's).............it results in a large amount of axial end play.

    My valve covers weeped oil with just o-rings. I installed gaskets along with the o-rings and no more leakage.

    I agree with the others, copper washers are much better for the head studs. Use 30 ft-lbs torque for the 8 large 10 mm studs.
  8. With the absolute proviso that all of the guys really know what they are talking about, I could point out that, like their British cousins, XS's do not--I repeat, do not--leak oil:

    They mark their turf!

    The "automatic chain oiler" line was funny--I ran the return lines from the breather on my '77 so that they sit right above the chain, like an oiler on an A10 BSA, and now I have a chain oiler, too!

    Something I didn't see mentioned, and it was probably taken for granted, but it's obviously important to have a book and if you are going to re-torque the head, use the correct pattern. Warpage is not our friend....
  9. Backroader

    Backroader XS650 Addict

    Wow, I have not done much reading in years.

    OK I will sift through this data and once I have got all the shit cleaned off I can start replacing things.

    Given the engine has only 2200 kms on it I am pretty sure this tired dried out seals. The bike sat for many years and was only recently driven last year, a total of 400 kms.

    I have spent 8 hours with a tooth brush and engine oil degreaser so far. When I finish, I hope this bike will look "out of the crate" condition.

    Reading the thread covering oil changes was interesting, so I figured I should chech out the filters at the dealer.... and I got a wake up call... the large filter on the under side is $69.00 cdn... that's not going to happen.

    Looks I am going to start bargin shopping for consumable products... To include oil, seals and what ever else this bike eats.
  10. yamaman

    yamaman xs650 addict

  11. yamaman

    yamaman xs650 addict

  12. Backroader

    Backroader XS650 Addict

    Thanks, I have checked out the site already... will start shopping there soon
  13. Backroader

    Backroader XS650 Addict

    Got the oil dropped today.... This the worst bike to change oil of all the bikes I have owned. Messy...

    Anyway I see why the after market changes are necessary as the filters are not overly functional. The engine pan filter had failed, the screen, exactly where it was supposed to.
    2197 kms and it was not working.

    Well I will get it all back together... run it up for while then drop the oil, as well as changing out/ cleaning them to see what goodies appear.

    The information on this site has been great, thanks all.
  14. I sing the praises of gaskets vs o-rings on the valve covers and timing covers as well. I don't even use the o-rings anymore. Also, with gaskets, you don't torque down as much, thus less chance of pulling the stud out of the head.
  15. 650Skull

    650Skull SSSSSSSSSlither Top Contributor

    On start up when the bike is cold, keep the revs down less than 2000 and let it stand for a couple of min to warm up. that way the pump won't be forcing thick oil through the sump filter and tearing the gauze.
  16. Backroader

    Backroader XS650 Addict

    Good point...I was planning on using warm oil for the first run up..... the best I have been able to get my gargage temp. up to is 12C, so I will put in the oil just before I fire it up.... going to run it then dump the oil to see what else apprears in the filters. Bought some Walmart 20-50 motor cycle oil...figure it ok for flushing the engine....

    Got metal filings this time....as best I can figure the bike has never had it's first servicing.
  17. inxs

    inxs xx

    - ...12°C...i wish, been working in my workshop this weekend-even with the heater i only managed 0°...still, its been pleasant riding :thumbsup:
  18. Backroader

    Backroader XS650 Addict

    Still -20C here at night with day time temps starting to get into single didgits.
    There will not be much riding here for another 6 weeks.
  19. Are the filings magnetic? If they are magnetic, they are likely from the starter bendix gears. They are metal makers.

    If they are not magnetic, then the filings are likely coming from the forward cam chain guide. The plastic chain guide has been known to completely dis-bond from the aluminum backing plate allowing the cam chain to rub against it. This could occur on a low time engine that has been idle for many years. High mileage engines eventually just wear through the plastic. Did you you find any pieces of black plastic with your filings?
  20. Backroader

    Backroader XS650 Addict

    Looks like the shaft has to come out to get the lower seal replaced.
    How do I avoid dropping the shim ?

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