Timing chain neurosis - is it right this time?

After my miserable experience on Sunday when I got the timing chain indexing wrong and had to take the head and barrel off after just fitting them off to lock the engine up so I could undo the worm nut to adjust the timing chain I have finally managed to get the chain back on.

I have attached a photo link to a picture of the chain fitted

http://i5.photobucket.com/albums/y162/m ... 02edit.jpg

Could someone confirm if I have it right this time please before I go any further with putting things back together. I have marked 10 rollers on the chain with white paint and also the punch marks on the intermediate gear and the camshaft sprocket. The marks on the timing pinion and the intermedaite gear are aligned although you can't see them in the photo

Is there any reason why this chain was not fitted with a spilt link in the first place as it is a right mither if you need to change a worn one!!!

Looks OK to me. A chain is as strong as its weakest link, and that's always the split link.

Cash

Why did you take the head off? or have I missed something here, I usually do.

Cash

It looks OK to me Mike.

The drawing in the factory book is of course misleading because it makes it look as if the marks on the sprockets line with the rollers which is not possible.

Presumably your problem last time was not one link between the cam and intermediate but rather the indexing with the crank pinion ?

Could the crank have rotated or could you have lined the mark on the intermediate sprocket with the crank pinion and the mark on the pinion with the chain ? Just a thought because they are 180° apart.

cash said:

Why did you take the head off? or have I missed something here, I usually do.

Cash

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Thanks Cash. There's a recent thread on stuck worm nuts I started if you want to follow the full story but to summarise:

Got the timing indexing wrong on a rebuild and needed to readjust it - the problem was the worm nut which was absolutely solid and would not budge. The problem was I couldn't lock the crank up firmly enough by any method I knew to get the nut started. (I know its a left hander). Eventually I gave up before I terminally damaged something and stripped the engine back down so I could lock up the crank correctly to get the worm off.

I needed to get the worm off to adjust the indexing between the intermediate gear and the timing pinion which I had somehow managed to get wrong.

Today I'm just refitting everything and being ultra cautious to make certain everythings all OK this time before going any further as I don't want to get the indexing wrong again!! I knew in my head with about 97% certainty that it was OK but just needed confirmation. I kept having a nagging in the back of my head that it just might not be right

79x100 said:

Could the crank have rotated or could you have lined the mark on the intermediate sprocket with the crank pinion and the mark on the pinion with the chain ? Just a thought because they are 180° apart.

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As I said before I just dont know how I managed it - I'm still in shock . It certainly wasn't mixing up the two marks on the Inter gear. I still blame it on old age, oil on specs or bad lighting. Thats my story and I'm sticking to it :lol: :lol:

I'm assuming by "locking up the crank correctly", you mean lowering the pistons in the bores, blocking them and bolting up a brace bar to the top of the jugs, thus working against the blocks with the pistons to still the crank?

Didn't mean to press you Mike, but I'm not getting any younger, frequently put oily finger marks on my glasses and mostly work in the evenings so I'm anxious to avoid making the same mistake ! :?

Ahh! senior moments, don't you just love them.

mike916sp, Just getting this part right will get it running. But don't say it's right till you have checked it with a degree wheel and an indicator on the exhaust valve. They have sold a lot of vernier cam sprockets because of factory stack up errors in the key ways. I know that My Commando needed one, it would have been 4 degrees out without one at the stock settings.
Far be it from me to make your "Timing chain neurosis" even worse. Just thought I would mention it is all. Not to make you paranoid or anything. Don't worry be happy. It's just a dumb machine. It doesn't have a mind. You control the vertical you control the horizontal. It was just a guy cutting key ways like he did all day, just like his buddy broaching key ways in gears further down the line. Really probley it's OK . Just never mind.

grandpaul said:

I'm assuming by "locking up the crank correctly", you mean lowering the pistons in the bores, blocking them and bolting up a brace bar to the top of the jugs, thus working against the blocks with the pistons to still the crank?

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Yep thats nearly what I did but not quite. Been caught out on that one before and won't do that again. Removed the pistons as well and locked up with a bar through the small ends onto blocks of wood resting along the cases.

Got caught out by blocking under pistons on a old XS750 Yam triple ('scuse languge) I used to have and ended up breaking a skirt on a piston.

79x100 said:

but I'm not getting any younger, frequently put oily finger marks on my glasses and mostly work in the evenings so I'm anxious to avoid making the same mistake ! :?

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I had a cunning plan this time - as well as cleaning my glasses before assembling I also used a 500w portable floodlight on the job - blinding it was :lol:

norbsa48503 said:

mike916sp, Just getting this part right will get it running. But don't say it's right till you have checked it with a degree wheel and an indicator on the exhaust valve. They have sold a lot of vernier cam sprockets because of factory stack up errors in the key ways.

Click to expand...

Know what you mean on that one and appreciate the post but its done about 38 thousand miles from new as it is (even though the timing more than likely will be out - actually its bound to be as I use the deg marks in the primary to set it and they can be way out) and when all is well it runs like a dream.

Not like it's a race machine (mind you some of my mates say I ride it like it is) when a vernior sprocket becomes a bit more necessary.