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.

 

[nighthog]

I finally completed the job - camshaft didn't arrive until 19th June along with the uprated (4-brush) starter motor I decided to go for too. I took 5twins advice and retorqued on the bench after a couple of days and yes, there was movement in a few nuts.
So here we are, back from a brief 10-mile or so shakedown ride and what have I discovered?

- initial carb setup is OK for running-in speeds but clearly the balance isn't quite right as the RHS has a lovely even beat but the LHS is a bit stumbly. I had the same issue with the BS34s until balancing them properly, but there are no vacuum barbs now so I can't use my Carbtune! There will be a way, I just don't know it yet. All I can do for now is the 'static balance' thing.
- tickover is too high at the moment. Simple adjustment ...
- motor feels sweet and surprisingly smooth if a little mechanically noisy, though naturally everything is fresh so no surprises there. Adjustments to follow.
- fuel tubing routing is awful and I'll rework it. I hoped to retain the either-tap-will-supply-both-carbs approach with tee pieces and also the sintered metal filters, but while what I've got works, it's plug ugly and can be much neater. I'll need to find some more suitable filters and feed each carb from each side, I think.
- I've got an oil leak on the LHS that looks like it must be coming from the crankshaft oil seal I just replaced. Damn! Must have nicked it somehow ....
- nobody should travel this path unless they're prepared to spend. I kept a spreadsheet listing everything and it makes for 'Don't show the wife!!!' reading. I know I chose some options that others wouldn't so costs could be contained a bit, but my choices have set me back a little over £2800.
- boy, do I need a beer ............

Also, came across a gotcha when doing engine in/out with the motor on its LHS. The weight of the motor pushes the shift shaft in so the hooky doodahs don't engage with the proper bits of the star-shaped thingy and you can't select any gears. If you're unlucky, you discover this after refilling the engine with oil and have to drain it all out again, remove the cover and clutch to find out what the problem is, give the end of the shift shat a sharp tap with a hammer handle or the like, then put it all back together again. If you know this, you don't actually need to remove the clutch as the end of the shift shaft is available but sadly I didn't. I had to find out.



A couple of pics of the current state of play:




So, nearly there and I'm pleased if a bit disappointed with the leak. That's a job for the coming days - now I need to water my beans (not a euphemism!) then work out what tonight's dinner will consist of. Busy, busy, busy .......


Cheers all -
Cliff

 

[Jim]

Well done Cliff!!

 

[nighthog]

Having congratulated myself on a job well done, the second time I took it out to put a few shakedown miles on it the charging system died. Much testing showed that the rotor was the culprit and sadly my spare was just as bad so bit yet another bullet and lashed out on a Vape PMA and ignition.

I removed all the now-redundant wiring from the loom and set about mounting the various bits - in case it helps others this was how I did it:

Coil


For the reg/rec I used a bit of the case from an old external hard drive (Maxxtor - remember them?) I kept for moment like this


For the ignitor I had some 2mm sheet lurking and made a bracket to sit between the air filters


Once all that lot was plumbed in and the wring secured, the next problem was finding TDC so I could set the timing. I'd made a tool as per Gary's method but thought a dedicated tool might give a better result so bought one of these from Poland



No bloody use at all. Not because the gauge doesn't work, but because the angle of incidence of the pin to the piston crown movement is around 45 degrees so the pin won't slide cleanly and no matter what I tried, I couldn't get anything remotely resembling consistent readings. So, went for the old fashioned stiff-wire-down-the-plug-hole-and-feel method and thankfully seem to have got that pretty damned close, as it now ticks over when warmed up at well below 1k rpm, close if anything to 500! Too slow in fact, and I'll adjust that up a bit when I could be arsed. But otherwise runs wonderfully at the modest rpm I'm using.

I now have over 400 running-in miles scooting off to various cafes and all seems wonderful - here's yesterday's visit to Cotswold Airport. And the arse end of a Hawker Hunter


500-mile service and retorque soon ......

Happy and relieved.
Cliff

 

[Jim]

Lookin' sharp, Cliff!