Here we go again

[gman]

sorry i forgot, when some one mentioned gapping the pick ups, what does that mean and how do i set the gap?

Gary

[DiverRay]

Gary,
To check the gap, remove the left cover to expose the pick up coils, remove the 6mm? allen bolt holding the timing plate on the end of the crankshaft. BEFORE you remove it, note the location !!! I usually set it to TDC, to make it easy. You then reinstall the bolt with something for a space, or use a shorter one. You can now use a feeler gauge to check the distance between the lobe on the crank and the flat on the pick up coil. If I remember, I've set mine to about .004". Check both coils, and then reassemble the parts you took off. Remember how many turns you moved the crank, so you do not loose the timing! I WOULD verify that your #1&4 pick up coil is set to fire at TDC by looking at the valves as you turn the engine over. This will also help to verify the correct coil is fired at the correct time. You need to remove the valve cover the verify operation of the valves. This should give you an idea of what the bike may need.

[prometheus578]

"Yes and no"

The fact that fuel spills out when i cover the carb bell mouth, does that mean the carbs are working?

During normal cranking/running operation, the vacuum caused by the downward movement of the piston is enough to cause fuel to rise through the jets and into the manifold
(Yes, I know there's no vacuum... just differences in atmospheric pressures, etc)
Anyway...
This action sucks a certain amount of air through the carb body which picks up a certain amount o' fuel.
Now, if one blocks off the mouth of the carb when cranking, the only place that the cylinder/carb can draw air from... would be through the carb vent holes to the bowl. Air gets sucked into the bowl, and as the jets are under the level of the fuel, it is pure fuel that gets sucked up first. Doing this results in fuel gushing up through the main jet circuit as well as pouring out from the air jets next to where you have your hand.
This just proves that there's fuel in the float bowl, though it say nothing about whether it's at the right level.
You state the spark plugs are dry. This would indicate not a spark issue (even if the spark was 180 degrees off, they still should get wet.
Rather, it's indicitive of a valve timing/ vacuum/ compression issue.
Valves may be opening at the wrong time... valves may be bent and not sealing... You may have a warped head(and the bike, too) meaning the vacuum and compression is escaping into the crank case... also the engine may not be cranking fast enough to provide the correct amount of draw to bring up fuel from the carbs properly, though it will surely do so when you block off the carb entrance.
A slow cranking engine will also give you a lower compression reading.
As for the manifolds getting warm...sounds like open intake valves.

Follow Ray's advice, as you were in there dicking with the pick-up coils, but as you never heard this engine run before installing it, while you have the valve cover off check the valve clearances and post the results.
Remember, that even if the clearances are within tolerance, this just means that the valves are fully seated... it doesn't mean that they're perfectly sealing or not burnt.

[gman]

I have checked all that has been recomended and when i took the cam cover off i found the following

1, I can pinch the cam chain about 15mm off the chain guied
2, when i line the cam timing marks up, the pointer on the timining disk is about 40 degrees off!
3, i cannot turn the crank using a spanner when the cam chain is tight.

i would load some pics but do not know hoe to !!

Any advise would be great

Gary

[skids]

You almost for sure have bent valves. Get a manual you are going to need it. You will have to line up your timing again and do it in such a way that you do not bend the valve stems if they aren't bent already. It would really be a good time to replace the cam chain if you end-up having compression after adjusting the cam positions.

Originally posted by gman
I have checked all that has been recomended and when i took the cam cover off i found the following

1, I can pinch the cam chain about 15mm off the chain guied
2, when i line the cam timing marks up, the pointer on the timining disk is about 40 degrees off!
3, i cannot turn the crank using a spanner when the cam chain is tight.

i would load some pics but do not know hoe to !!

Any advise would be great

Gary

[randy]

when i line the cam timing marks up, the pointer on the timining disk is about 40 degrees off!

The pointer is 40 degrees off of which mark? Off the "C" mark? That's OK.

The "T" should line up with the pointer when the cam marks are lined up with the cam caps. If it does, you're almost there, then turn the crank once more around to the "C" mark and reset the cam chain tensioner. Then check valve clearances and compression.

[prometheus578]

"Hoo boy..."

I'm afraid I have to agree with Skids on this one.
Doesn't sound good at all.
Ok, by what you have written...
What you mean to say is that when you set the timing wheel on the crank to the "T" position the timing arrows on the cams don't line up, yes?
Sadly, it would seem that due to age and wear, the timing chain has stretched, which is normal. Maybe the previous owner of the engine never adjusted the timing chain tension as per normal maintenence... maybe the cam chain tensioner failed, or maybe the chain just had too much stretch for the tensioner to compensate for. Either way, not that it matters, but what you have is an engine who's chain jumped several teeth, and as a result the pistons have bent several of the valves.
You didn't post what the valve clearances were.
Normal clearances for exhaust would be 0.21-0.25mm. Anything radically different from that... and you have a valve... that due to it's head being bent... cannot fully seat itself.
(I bent an exhaust valve once... it's clearance, when checked was 0.80mm)
There's other tests that can be done, like a "leak down test" but would require special tools, etc.
Bring the crank pointer to the "T" mark, remove the cam chain tensioner and try to reset the cams on their marks. Reinstall the tensioner(after retracting it), slowly crank the engine over by hand till it's on the "C" mark(watching to make sure the cams don't jump the chain) and reset the cam chain tensioner. Crank the engine using the starter and check again for compression.
Remember that this engine runs backwards. The chain moves from the front of the engine to the back over the cams.
Let us know what happens.


Good point, Randy. Make sure you're using the right mark!

[gman]

This goes on and on,

i have re checked the 3 points of timing and they are way off again (re set them yesterday), when i pulled the cam chain i got loads of slack again. I checked the chain adjuster and that is fine plenty of room for adjustment. I did notice again that the cam chain seems to slip around the crank shaft sprocket, is that possible? i think at the very least the cam chain is knackered? how do you change them any suggestions?

This project is driving me niuts, i was told a long time ago the XS projects are interesting !!

Gary

[Ken Talbot]

Originally posted by gman
I did notice again that the cam chain seems to slip around the crank shaft sprocket, is that possible?

Yes, this is possible if the cam chain is not actually hooked on the sprocket. There is room for it to drop in beside the sprocket. There will be an inordinate amount of slack, and the chain timing goes off as soon as you start rotating the motor. Remove the cams and the slider, and look down the gallery with a good flashlight. If the chain has dropped to the side, it will be easy to see.

[skids]

Whenever you mess with the cam chain, the bike should be on the centerstand. I learned that the hard way.

Originally posted by gman
snip. I did notice again that the cam chain seems to slip around the crank shaft sprocket, is that possible? i think at the very least the cam chain is knackered? how do you change them any suggestions?



Gary

[TopCatGr58]

Gman,

I hate to say it, but if you've realigned the cams, and THEN rotated the crank/cams and found them out of line again, then you have probably already bent valves! You probably should pull the head OFF and check them, you'll be able to then replace any you find bent before going thru the trouble of getting the cam chain routed properly, and doing a comp check just to find that you probably won't have any in 1 or more cylinders!

IF you don't have a manual, you'll want to get one so that when you get the head/valves fixed, you will put it back together without the risk of bending them again!

Also, even though the chain tensioner may have plenty of adjustment, the locking bolt may NOT have been holding the tensioner rod securely, and this may have contributed to the problem to begin with, allowing the chain to slap and jump off of the crank sprocket!?
T.C.

[John]

I hate to, but

I have to contradict you T.C. When I was reassembling the top end of the Bag Lady, a few weeks ago, I did the same thing. Had all the timing marks aligned, and when I rotated the engine 180 to install the second bolt into the cam sprockets I noticed the cams hadn't moved after the engine was turned 180. I was afraid I had bent some valves, but after checking out the cam lobe positions, I noticed that when the timing marks are alinged, there are no valves fully open. After correcting the problem, I did a leak down test, and the results were good. No bent valves. The bike runs good, and I had it out for it's first shake down cruise today. Just a few little tweaks, and it's done.

[prometheus578]

"You may have just been lucky on your reassembly, John."

In Gman's case... whatever happened happened to an engine that was running at the time... prior to him buying it.
I may be wrong, but I think that he just installed the used engine... no major component swapping done on his part that might have caused the chain to come off.

[gman]

that is just it, the only thing i changed was the cam chain tension thing, i had not rotated the crank until i installed the engine and then it just would not start
will take the head off today and post back

Gary

[gman]

ok, i have taken the head off, there is no damage to pistons etc, all looks good. I am going to use my other head to rebuild the engine as i know that is good. Should i use the cams etc from the old head as again, they are good?
The original valves look ok however with out a compression tool i cannot really say. I need to get a gasket set and then off we go, well i hope.

Is there an easy way to re engage the cam chain on the crank sproket???

Cheers

Gary