think i may be screwed...

[BA80]

Greg, he said he noticed the cam chain tensioner missing AFTER he spun it over with the starter................bummer.........definitely kissed some valves.......

He also said that the timing marks still lined up. If the chain didn't slip it couldn't have bent the valves, however, if the engine was turned over with the chain OFF and the cams INSTALLED there will definitly be bent valves.

A valve would have to be bent REALLY,REALLY bad to hit the top of the piston with the valve timing correct.

You see what I'm getting at?

[Nick7777]

even for the 81's

[BA80]

Yup. An engine will run, however badly, with a bent valve without it hitting a piston. I truly don't think a valve could be bent badly enough to hit the top of a piston if the valve timing is right. The hardened steel would break and the head would snap off before it could bend that far.

If that was the problem it wouldbe the first time I've seen it in ANY engine and I've been into a lot of them.

Have you looked into the cylinders to see if maybe something may have fallen into one?

If you can't find the reason I guess you should pull the head.

[bikerphil]

If you have the valve cover off already and can rotate the engine enough to measure the valve clearances, a huge out of spec clearance will indicate a bent valve, JAT

[DGXSER]

I would agree with Phil, check valve clearances if you can. A bent valve will show up as a big spacing, well out of spec. Sounds like you can't get enough turning on the cams to check though. Takes two revs of the crank for one of the cams.

Do you have the plugs pulled, are you sure your not just getting to the compression stroke? I know, kind of a stupid question, but had to ask.

Pulling the head is no fun and will take an investment in a head gasket (yes, I know some folks have made their own or reused them, not something I recommend to someone who is learning as they go).

[James England]

An engine will run, however badly, with a bent valve without it hitting a piston.

Presumably the piston hit the valve at least once, in order to bend it though?

So... the story is.... he gets a bike, spins the engine on the electric start and then finds it has no CCT. Now it won't turn past a certain point, even with the marks (now) lined up and the CCT installed. I've seen two XS1100 engines, both unused for several years, where a valve has rusted in the open position and acquired so much rust that the valve couldn't shut, even when the cam would let it. The timing was lined up, all correct etc etc but the valves were rusted open. Turn the engine and the piston hit the two frozen valves and locked up.

His best bet, IMO, is to get the valve cover off, remove the cams and look at the valves. If any are lower than the rest, then it's time to take the head off and have a proper look.

In general, I've found that 'barn find' bikes are usually barn finds because something happened to the engine. They get slung in a shed, with the owner having every intention of fixing them, and... they get left. Then they are discovered as holy relics "unused for 10 years", with whoever now owns it selling the bike with vague caveats like "hasn't been run for years but I see no reason why it won't work" or "Doesn't run, probably old gas" etc etc. An old bike with a CCT missing, says something.

We can all speculate here (and get cocky with each other) but what's needed is data. The valves need looking at from the top and, if necessary, from the bottom.

[natemoen]

I say you first need to go back and redo all of the timing procedure. Start by lifting the cams and then check and make sure your "T" mark is really at TDC becasue that pointer can get bent. Then go through the timeing procedure. There are also marks on the right side of the cam gears that need to be pointing up (up-ish) when the other marks are lined up, and they really are not mentioned in the book.

I will attest to the fact that sometime everything can line up but something still isn't right. Redoing it is the only way to know. So redo it before buying unnecessary parts.

Everyone seems to be very doom and gloom lately...

[mack]

missing cct

you do have to wonder why the cct was missing in the first place. If it was my motor I'd be pulling the head, inspecting the valves and springs, then probably lapping them and replacing the oil seals.While it was a part I'd also look closely at the pistons and sleeves during rotation. For the time it takes to pull a head and get good "piece of mind".

[ViperRon]

I would cut the problem in half so I would know where to go. Some have sort of suggested this but in different light. First make sure it is out of gear by shifting to neutral and turning the back wheel to ensure its out of gear. This eliminates the transmission. I would take the cam shafts out the plugs out see if it can rotate by hand no starter. If it turns over the problem is probably with the head. You will have to support the chain and it will drag some in the engine while turning but if you keep it from bunching up the engine should rotate by hand. If it turns it will eliminate something else in the engine from locking the motor. If this works then turn engine to proper position put cams back in and try timing again by using the manual procedure. If it then does not rotate with timming set correctly your issue is with the head and you will need to remove it to fix it.

[mmaddix]

I'm thinking there may be some rust in the cylinders from sitting. As long as the valve timing is correct and the thing WILL turn with the starter you might just put some automatic transmission fluid in each of the cylinders and turn it over with the plugs out.

Cover the spark plug holes with a rag or something because that stuff will come shooting out. That will get a good coating in the cylinders.

Pour some more in there and let it sit overnight and repeat, maybe a few times. Then just get it running and ride it. that should loosen up the rest of the rust and any stuck rings there might be should loosen up with some heating and cooling.

It cant hurt. That's what I would try.

I would try this because I bought my 78E and I used the kickstarter to make sure the engine wasn't seized. It turned over fine. Well it was on my porch for a few weeks while I worked on stuff other than the engine. I had rags in the intake boots and in the exhaust just to make sure nothing got in there. One day I went to use the kickstarter to try to turn it over and it made like half or 3/4 of a stroke with the kickstarter then nothing. I couldn't get it to budge. I took the spark plugs out sprayed WD-40 in each cylinder and let it set for a few min then it kicked over just fine. And once I gt it started a bunch of rust particles came out the exhaust.

[Nick7777]

well i just pulled the head off... aside from the ridiculous amount of crud on the pistons and sleeves there was imprints on the pistons where the valves most likely had touched, no metal displacement though. i also noticed all of the exhaust valves had about a hundred thou gap between them and where they seat on the head. if im not mistaken all of the valves should be seated flush right, and one of the adjustment discs(for clearance between the cam) was missing. so would these exhaust valves be stuck open and perhaps my problem

[James England]

The imprints on the pistons are cast in and supposed to be there, so no damage done there. No shim on one valve??? Not good. Has it been run like that, do you think? Yes, the valves should close fully... are you saing you can get a feeler gauge right past them when they are 'closed'?

Now the head is off, you can rotate the engine by hand and watch the pistons move up and down. Check the bike is in neutral and that the cam chain is clear, then turn the engine using a wrench on the timing plate under the left engine cover. You need to establish that the crankshaft will turn fully and that the pistons move up and down.... then report back!

[Nick7777]

pistons and crank rotate just fine, the bottom side of the exhaust valves where they meet the piston have a pretty large gap .1" i would say maybe even an 1\8th of an inch. it has not been ran by me but nothing would suprise me with the nightmare this bike has been since i bought it a few months ago... the valves should be completely seated on the bottom head gasket side right, or are they not the same as automobile valves...

[BA80]

well i just pulled the head off... aside from the ridiculous amount of crud on the pistons and sleeves there was imprints on the pistons where the valves most likely had touched, no metal displacement though. i also noticed all of the exhaust valves had about a hundred thou gap between them and where they seat on the head. if im not mistaken all of the valves should be seated flush right, and one of the adjustment discs(for clearance between the cam) was missing. so would these exhaust valves be stuck open and perhaps my problem

Rust.........sitting 10 years will rust one up no matter where you have it stored. Can you post us some pics Nick? So we can see what your dealing with.

[Nick7777]

i would be more than happy to, could someone give me directions on how to post pictures on this site im an amatuer