Hi Andy and welcome!
The XS650 normally runs 20W50 viscosity oil - so you are already using a lower viscosity (i.e. less “sticky”) oil. Frankly, I wouldn’t do that for too long and particularly not in a hot climate like Los Angeles. These old gals run hot enough and if you got into stop and go traffic (unlikely as that might be in LA....), you could cook the engine.
The only other caveat with oil is to
NOT use any oil that has an API “Energy Saver” label on the bottle. This label means that, while the oil provides really good lubrication, it contains an additive package that
will cause the wet clutch to slip. There is an urban legend that
any synthetic oil will damage a bike clutch - but this is wrong
. The issue is not the source of the oil but rather the presence of that special additive package which messes up wet clutches. I won six bottles of synthetic Harley Davidson 20W50 oil in a draw at my vintage bike club and have been using it in my XS650s - no problemo. It says right on the bottle “
Compatible with wet clutches”.
Now, back to your question about hard shifting. You’ve done everything you can (if not too much...) in terms of reducing oil viscosity and I think it sounds as thought you have sorted out the shifter shaft - so IMO, you need to look at the clutch adjustment and then at the clutch cable and actuator “worm” (which lives inside the LH engine side case cover), and then at the clutch itself which lives inside the RH engine case cover - in that order.
CLUTCH ADJUSTMENT
There are lots of discussions on the XS650.com Forum about clutch adjustment and with good reason. The XS650 does have chronic difficulties with shifting and particularly with finding neutral while stationary. Most of these problems are actually related to incorrect clutch adjustment or poor clutch operation due to worn parts or incorrect assembly. Adjusting the clutch requires several key steps:
- back off the cable slack adjuster on the LH handlebar clutch lever so that the cable is slack;
- under the little chrome cover on the LH engine case there is a small JIS (looks like Phillips but it isn’t) screw with a locknut. Loosen the locknut and then turn the JIS screw in until the you feel it
juuussstt bottom out - then hold the screw still while you and tighten the lock nut. (
and don’t go crazy on it).
- now go back to the LH handlebar lever and adjust the cable slack until the clutch lever will
juuuust move a little before it begins to pull on the clutch cable.
If that all doesn’t work then go to the.....
CLUTCH ACTUATOR (
aka the clutch “
worm”)
The clutch actuator worm needs to be disassembled and lubed to work properly and there is lots of info on the XS650.com Forum to help you do that little job. Just search for “
clutch adjustments” or “
clutch worm” and you will find it. If you need a new worm, they can be had NOS on the web or a reasonable replacement is available at MikesXS. The LH side case gasket doesn’t seal anything - it is really there to keep water out of the alternator so don’t fuss too much if you mess it up when taking it off.
While you are in the LH side, check the seal on the clutch pushrod - it is a common source of oil leaks. The seal can be replaced without too much hassle - search on the forum and you find tons of advice and even videos on how to do it.
Also, be sure to tighten up the big nut on the countershaft sprocket (the one that drives the chain). That nut tends to loosen off and the seal behind it will then leak. The seal itself is almost always OK - and so tightening up that big nut will
normally stop the leak. Note the sheet metal anti-rotation washer on the nut - fold the tab down
BEFORE tightening and then fold it back up after you torque the nut.
The other thing to check at this point is the clutch cable - is it in good shape or frayed and does it need lubrication? New clutch cables are cheap and usually better than anything that is 40 years old.
Motion Pro branded cables are reputed to be good. Be sure to check your shop manual (
without which you should not work on the bike) and route the clutch cable properly under the fuel tank and in the vicinity of the carbs.
I can confirm that the correct clutch - and throttle cable routing is NOT obvious and it is VERY easy to get it wrong and cause poor clutch - and throttle - operation.
If working on the clutch actuator worm and the cable doesn’t cure the problem, then you’ll need to get into the...
CLUTCH
If you get into the clutch itself, you
WILL need a new engine side cover gasket because it does seal engine oil in and you don’t want it to leak. There about 10-11 6mm socket head cap screws (Allen head bolts) that hold that cover on. You need to keep track of which ones go where (there several different lengths) and which ones have little copper sealing washers on them. Basically, all of the lower 5 or 6 SHCS have a copper washer which helps them to seal engine oil - while the upper 5 or 6 SHCS do not need a copper washer. BTW - most of the folks who have done this job seem to have found that the copper washers are missing from their bikes - and as a result, they often have a slow oil leak on the RH side...but its easy to fix.
Again - there are lots of XS650.com Forum threads on servicing the clutch - I’d read a few before you start. Here are a couple of other general tips:
1) Getting into an XS650 clutch is not a particularly big or difficult job - and the easiest way to get access is to simply lean the bike over on its LH side and sit down beside it. I propped mine up using a car jack stand under the LH exhaust pipe which I covered with a rag to prevent scratches on the beautiful chrome (thanks GeorgeOC!!). This tilting operation prevents all the oil from leaking out and makes working down there much more comfortable if you don’t have a bike hoist.
2) You will need a big metric socket to remove the clutch centre nut (and it may be a 28, 29 or 30mm nut - MamaYama used
all three sizes, seemingly at random
wtf
- so there is no way to tell which size you’ll need before you see it “
in the flesh”). So much for the ultra-methodical Japanese....
These sockets are available at Harbour Freight and are not very expensive. The best way to get the nut off is with an electric impact wrench (i.e. a rattle gun). I simply put the bike in gear and held the rear brake down - and it came off in a flash. I did the same thing to torque it back on after the repair.
You’ll also need an
impact driver (which is not electric but requires a good-sized hammer) because the stock clutch screws have JIS (sort of like Phillips) heads and they are often buggered-up. An
impact driver is definitely the way to go here and you might want to replace the stock screws with some nifty socket head cap screws or “SHCS” - aka Allen screws). If you do switch to SHCS, be sure they are the correct length BEFORE you install them. If they are too long, you will damage your engine case and the clutch will not work properly.
A screw driver with the correct
JIS bit (the best brand is called
VESSEL - available on eBay) and a set of these tools is essential for working on Japanese...anything:
bikes, cars, cameras etc. Again JIS (Japan Industrial Standard) looks like Phillips but are sufficiently different that a Phillips driver will often strip the head of a JIS screw. As noted, a JIS
impact driver (you want the silver handled IMPACTA #3 JIS driver) is ideal for doing a 650 clutch because those six clutch screws are often tight and sometimes have buggered-up heads.
You do NOT want to have to drill them out.
3) You will find a whole bunch of special washers, spacers and funny little parts in the clutch assembly - so have a clean towel on which to lay them out and keep careful track of what goes where. Having said that, it may be that someone has already been in there and reassembled the clutch incorrectly and that is why your shifting is difficult - so get a blow-up drawing and check carefully as you disassemble it. There is only one correct way to put it together - but lots of incorrect ways.
If you find that the little axial thrust bearing is bad - don’t despair, the MikesXS replacement is cheap and is reported to make a BIG improvement in clutch function.
4) If your electric starter doesn't work very well - the problem is nearly always starter gear #4 which is located inside the RH engine case just behind the clutch.
Sooo, while you are inside the RH engine case - you should check your electric starter gear #4. Again, this is a very common problem with the XS650 and yet, it is a very cheap and simple repair and so I'd advise you to search the Forum for threads on the starter gear repair. You will find TONS of good info on it.
I’ll close by wishing you luck and encouraging you to ask lots of questions, get a shop manual (downloadable for free) the proper tools and please post lots of photos.
Cheers
Pete
