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Catastrophic engine damage/noise?

Before cranking it with the starter, I'd use the bolt under the cam chain cover to turn it over by hand a few times to make sure that everything moves ok without effort.

BTW don't forget that the Haynes manual recommends that, following an engine overhaul, ie with a dry engine and a new filter, you should put in 3.4 litres of oil, instead of the regular 2.8 for a simple oil/ filter change.
 
Fantastic! I love engine rebuilds 😂
Yep you guessed right a blown headgasket
 

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Hi guys. Just getting around to timing the engine and hopefully soon, putting it back in the frame. I’ve tried my best to get the timing marks perfectly in line, but I’m struggling at the moment and don’t know what exactly is acceptable.

The cam chain is taut now and when turning the crank, all marks return to the same spot, but the mark between the cylinder head surface and the line for the cam shaft sprocket is different by about 1.5mm. Is that acceptable? IMG_9076.jpegIMG_9077.jpegIMG_9078.jpeg
 
I don't have any answer about the exact spot for the valve timing mark.
Make sure to remove all slack in the chain,then install the tensioner,etc.
 
First, get the crankshaft dead nuts on the mark.
Next, get the all slack out of the chain to the EXHUST CAM, lined up on the mark- That's now good.
(any slight longer indicates chain stretch or sprocket wear).
One tooth off one way or the other will BE VERY NOTICIBLE...

Next, get all the slack out to the INTAKE CAM getting the marks on again to the cylinder head.

Lastly, the rest of the slack will be taken up with the chain tensioner (on the rear side of the chain).

You can rotate around and bring the marks back, just to re-check.

With that said, your good to go.

.
 
A worn cam chain (even one with just a few thousand miles) can cause the marks to be slightly off. With a used chain the best you can hope for is "close enough". When aligning the marks, be sure to compensate for the chain stretch, i.e. the exhaust mark may be slightly obstructed.

What you are showing in your photos is the exhaust sprocket may be off by one tooth. Follow Scott's advice and see where you land.
 
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Hey, yeah I’ve given it another go and can’t line it up any better than that, so I’m quite unsure whether to say it’s fine, or keep trying to get it absolutely perfect…
 
Hi Gary. I did attempt to shift the intake camshaft one tooth, but that just made it look further out, so reverted back to this configuration. I hadn’t really taken into account the fact that the crankshaft is new, so I guess the chain won’t line up exactly as it did with the previous crankshaft.

I’ll take another look in the morning but I’m not sure I can get it much closer to be honest…
 
Just for S & G's (you may have already tried this)

Get the intake cam lined up (don't worry about the crank this second),
then set the chain to the exhaust cam, lining up the mark on the exhaust (to the head),
see where that lands ya (mark and tooth wise..

Also, as you've gone this far, might just put a new chain in it.
You don't want to do this over again and move it a tooth


.
 
From my reading on the forum, the tensioner is more commonly replaced than the chain. Maybe that has already been done here and I missed it.
A new tensioner will not change where the marks line up on the cams and crank.
If the chain is stretched, marks will be off, period..

A new tensioner will help with a sloppy/ loose worn chain but the marks will STILL be off(chain is still longer than it should be).

.
 
A worn cam chain retards the valve timing,which will hurt your low-midrange power,but give you more top-end,to a point. A new OEM cam chain(pt.#94591-49120-00)from Yamaha/Partzilla is on sale for only $33.28,but the cam chain tensionor is more @ $181.57
Good insurance on your rebuilt engine.
The timing will be floating around alot,if left as it is.
 
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Hi guys. Thanks all for your help and advice. In the end I didn’t adjust the timing as I felt that it was just slightly out due to the things I mentioned, and not likely out by a tooth. I measured all the valve clearances and believe they’re all in spec.

Yesterday and today I went about reassembling the bike. There’s been a few hiccups along the way, namely I need a new throttle cable (I’ll possibly replace both), and the neutral switch isn’t working.

That all said, I primed the oil system with plugs out, it sounded ok when cranking, then went about putting the cooling pipes and radiator back on. Filled it with coolant, a quick once over and decided to try and start it.

It started with relative ease as you can see from the video. I then went for a quick ride around the block and the bike seemed to run fine, sounds fine and no obvious issues yet, so fingers crossed. I’ll probably check the cylinders for compression but need to get the tools for that.

It’s 6pm on a Sunday night here so I’m gonna cover the bike up for now, and have a well earned pint of Guinness.

Have a look at the linked video. I’ve cut my head off for privacy and will probably delete it eventually but yeah, any ideas or thoughts are much appreciated.

Again, thanks for all your help, tips and advice. I’ll stay on this forum and continue to contribute where I can. Also will continue to update this thread as time goes by with hopefully only ever increasing good news.

https://drive.google.com/file/d/1mj-Gdl6edXU5F8el-Djdg7-uMJkSfi-6/view?usp=drivesdk
 
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