valve timing..NOW BENT VALVE

[SiP]

Got the head on and the cams, but am having a nightmare doing my valve timing. I set it all up as per the book but when I do my rotations the marks on the cam boss and centre bearing are always out, plus the last time I did it I suddenly realised that I was turning the crank but the cams weren't turning. I was absolutely positive that I got all the slack out of the chain and it doesn't seem to have broken (not that I'd expect that anyway) but I'm guessing that it's jumped the crank.
Was pretty pissed yesterday - I had a high hope of actually getting it running.

[SiP]

By the way when I bought this one I was also looking at another one that was a grand more - kinda wish I'd gone for that one now. By the time I'm all done this one will be more expensive - especially if I end up having to do a complete tear down.

[Snow]

I still have a long ways to go before hitting guru status, but I'd say it does sound like your cam chain isn't on the crank gear and if you have spun the motor around (as per the instructions in the manual) with it like that, you may have damaged your valves..

I do recall last time I set the timing (after changing cam chain) that I had a devil of a time getting 'em lined up right - I think it actually ended up that the dots on the cams were just slightly pointing outward (Exhaust towards front, intake towards back). Hopefully a real guru will pipe up.

The good news is that complete heads can usually be had pretty cheaply or you can just rebuild the head.

[AlanB]

Hi Guys,

Just to hit the basics; Are you turning it the right way? XS turns the opposite way to almost every othe bike on the planet. The "Tight" run of the chain is at the back of the barrel, So if you have the left cover off, the crank turns clockwise.

AlanB

[TopCatGr58]

Hey Sip,

Snow is right in that IF you have turned the crank over 360, you may have already bent a few valves. Not ALL of them, but just possibly the ones that were being pressed down/open when you fit the cams in and tightened the bearing caps down!

Hate to say it, but it's better to go ahead and take the head back off, and inspect them NOW! I inadvertantly bent a couple of valves by having the head OFF the engine, but put both cams in and turned one at a time....2 valves cannot occupy the same space at the same time, bent an already stickign out exhaust valve with an intake valve as the cam spun around! Had the engine all together, torqued, valve timed, did a static compression check just for grins....got ZERO on one cylinder!
Had to tear it down anyways to find and replace the bent valve, and then put it all back together again! You can use the same head gasket since you haven't actually run the engine yet!

I see you have a manual...you stated doing this by the book, so I/we can only assume that you are/were turning the engine the correct clockwise direction as from the left engine timing case!

IF the cams weren't turning when you turned the crank, then the chain probably has slipped off of the sprocket on the crank. AFTER you pull the head and check for bent valves, IF you don't find any, and have confirmed ALL valves are sealing by removing the cams, and putting some gas into the head with it upside down, and NOT seeing any fluid leak past the valves, then you can put the head back on.

THEN, before you put the cams in, pull the chain up snugly, and then turn the crank and see if you can feel the chain moving/turning. Once you confirmed this, then you'll need to keep tension on it as you thread the cams back in place, along with the sprockets. Yes, the dots won't necessarily line up EXACTLY straight up, but you should be able determine that they are NOT a WHOLE TOOTH off position. Don't know how you put both of the cam sprocket bolts on without being able to turn the crank and cams together? That's how you're supposed to do it, positioning the sprockets with cam dots up at TDC, put in the top most bolt on both cams, then SLOWLY turn the crank and the cams to expose the lower bolt holes, put those bolts in, then turn the engine around a couple of times and stop at TDC and verify the dots alignment. Once they are in position, then TORQUE the cam sprocket bolts!

Hope you don't find any bent valves!?

[SiP]

Yeah I think you're right I'll have to bite the bullet and strip it - again.
On the last attempt the cams were turning initially and then stopped, that's how I got the bolts in - it made getting them out interesting to.

[SiP]

valve bent

I pulled the head off again and did the gas thing that topcat suggested and sure enough the inlet on #4 is dripping.
POOH!!!
So now I need to know if there's a particular problem getting a new va;ve or are they a really common as muck part that anyone will have. As for changing it I hope to be OK as the mechanics where I work are really helpful and will ahve all the tools I need.

[TopCatGr58]

They are still available from Yamaha....IIRC, but are a bit pricey!
You may want to post a message in the PARTS WANTED FORUM, perhaps Andreas has a spare head or some spare valves, or someone else who has canabalized a head for some valves has some left over!?

Sorry, but glad you found it now, and not after trying to start it!
T.C.

[SiP]

Don't be sorry, I appreciate all the advice. Maybe I'll luck out and someone will read this thread who has a valve??
I suppose I'll have to re-shim as well won't I

[SiP]

I just checked the parts for sale and some guy in BC has an 81sh cylinder head and he says no part over $120. Might be easier to just get that.
Thoughts?

[TopCatGr58]

Re-shim, most likely, and at least a valve lapping to get it to seal, although the purists would have you get it match ground to the head!
T.C.

[andnew]

Don't have a lot of time, but...

if a valve or seat or two need to be ground or if an 82 XJ valve will fit...

I have a head shop in my garage and a spare loaded head for a 1982 XJ11. Two bent valves :-)

Cheers,
Andy

Hah! need to update my signature.

[TopCatGr58]

Hey Andnew,

Thanks for the offer, however, I just checked and SIP needs to update his PROFILE or Signature as well, cause it only says XS1100, we can't tell what YEAR or MODEL he has, and the 78-79 years can't use the XJ valves, the XJ's are too big!
T.C.

[SiP]

I'll get on that signature/profile thing.
I have '81 xs1100 H

[andnew]

Compared to the Beemer nothing is too big. :-) :-)

Like I say, i have a low tech old school Sioux valve grinding set, and cylinder CC measuring equipment.

I've already built all the shims needed for my tooling to work on XS or XJ heads. If someone needs help with these, it's my hobby not a vocation. (read you'll owe me beer when we finally meet :-) ).

Cheers.
Andy