And for my next trick ....

[5twins]

Set the motor on the TDC mark, then install the cam, and connect the chain on top of it. You'll need to "jump" the chain around on the crank sprocket as you rotate the motor to keep both ends up on top. String some wire through both ends of the chain so you can drop them down into the motor a little to provide slack for "jumping" the chain around the crank sprocket.

 

[nighthog]

Hi Raymond, perhps these pics illustrate the conundrum a bit better:



I've been pretty careful all the way through and can't think of any time that the old or new camchain could have lost engagement with the crank sprocket. If I could make that happen now, I would!

 

[Jim]

see next comment.

 

[Jim]

I think I'll have to join the camchain then fit the cam with the bearings off until I can get it in the right position with the pistons at TDC, then fit the bearings.

Unless someone has a better idea?

OK, I think I know what you're saying now... the end of the chain isn't where it needs to be to riveted when the pistons are TDC.... yes?

Take and rotate the crank until the chain ends are where you want them. Then put some slack in both ends (leaving them tied off still) then start turning the crank to where you want it. As you turn, wiggle the chain up and down to keep some slack around the crank sprocket. It'll take a bit of wiggling and finagling, but eventually you'll get the chain around to where you need it.

 

[nighthog]

Thanks Jim, that was what I meant and I did have a brief go with no result but I'll try again tomorrow. Bit pissed off with it at the moment!

 

[Jim]

May sound kinda funny, but just wiggle the two ends like two puppets on a string. Actually sounds hilarious.... but there's room around the sprocket.
Keep dancin' the "strings" and you'll feel the chain slip a tooth and get a little closer. Rotate the crank in the intended direction... and dance some more. It'll take one tooth at a time, but it'll work.

 

[nighthog]

And work it did. A bit fiddly but eminently doable.

The barrels were a pretty tight fit when I dropped them on, so I cut a few bits of 15mm water pipe and just snugged everything down to make sure the base gasket is seated properly. No head gasket. When I get the cam, I think I'll do this again but of course with the head gasket in place. It may help with fitting the rivet link.

 

[5twins]

Yes, new chains are very tight so you will most likely need to do as you have to get the ends to mate up and get the master link in. I have a plastic jar full of spacers cut from old handlebars I made up special just for this. Once you've run the engine, the new chain will loosen up rather quickly initially. so do check it's tension within the first 50 to 100 miles. Along with head nut re-torques, I'd check the cam chain tension several times in the first 1000 miles. By then, the head nut torques and chain stretch should stabilize and you can just follow the normal maintenance routine for them. For me, that means checking the head nuts about once a season and the cam chain tension at every oil change.

 

[nighthog]

Thanks, 5T. I figured 1st retorque after 3 heat cycles and check valve clearances & camchain tension then too. Repeat after around 50 miles, again after 100 more, repeat until oil & filter change at 500 or so. And all the checks again. And so on ....
I have a hefty investment in this motor and intend to do my best to make it last!

 

[5twins]

You can actually do your first torque check after the motor is assembled and has sat at least overnight, before it's even been run. You will most likely find a few loose fasteners due to some initial new gasket compression.