Triumphrat

rmak

I'm still waiting for one of my other bikes to sell so that I can get a Scrambler. I found that Thunderbike makes a Stage 1 kit for Scramblers that they say boosts power considerably. The kit comes with new cams. I know it's a little premature to think about, but I plan to make major modifications as soon as I get the bike.

How hard is it to change camshafts in these twins? I have a Haynes manual, but unless you're actually doing things using the book, just reading the words about it get confusing, at least for me.

Is that a job an amateur mechanic like me can tackle without special tools? Or is it best to leave for the experts? If so, would you take it to a dealer or look for another kind of shop?

Thanks,
Rich

Kurtis

It is easy to swap the cams without taking the engine out of the bike, which is one good point. Plus the camchain doesn't directly turn the cams, just an idler shaft with a gear on it, so the camchain can be left alone.

The biggest problem was preloading the anti backlash gears on the camshafts and holding them whilst timing the shafts.

It's not massively difficult, but if you are worried, then it may be better to send it in just for your own peace of mind.

raproe

If you already have the Haynes manual you are off to a good start. The Haynes manual rates each job with one to five wrenches. It gives removing and replacing the cams three wrenches; "fairly difficult" or suitable for a competent DIY mechanic. If you think that describes you, it pretty much goes just like in the manual. The nice thing about the cams on these bikes is that they come out without having to undo the timing chain.

I did the cam removal when I reset my valves and the only pointers I would give are:

Carefully follow the manual instructions on lining up all the timing marks, including removing the alternator cover to line up the alternator. I took a digital picture of everything before I took it apart to be double sure of how to line up all the marks. If you do the job on the side stand, you won't have to drain the oil since very little is in the alternator case when the bike is on the side stand.

Be really careful when you remove the camshaft holder bolts since it is easy to strip out the sockets (I learned the hard way). I recommend using an impact driver to break them loose.

Cover all the oil return holes in the head so you don't drop loose pieces into the crankcase.

Be sure to have a locking pin something like the Haynes manual (see drawing below) or the Triumph tool so the anti-backlash gadget doesn't unwind. With new cams you might have to swap the anti-backlash device and will also need the Triumph tool (or something like it) that winds up the spring.

Good luck.

Rich

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"....by its very nature, a single-tracker is in unstable equilibrium, i.e., it cannot, when stationary, stand up by itself."

English_Spanner

In your drawing, why have the metric dimensions been converted to inches?

Skyblue62

To help answer your question English - take a look at where he lives. They still prefer the old feet and inches over there

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Ian

SuperMan

Yeah why? Especially since we all know that the metric (frog) system by far is the superior one.
Right?

mglemans86

Originally Posted by English_Spanner
In your drawing, why have the metric dimensions been converted to inches?

If GOD wanted us to be metric he would have had 10 Apostles

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Piles of Miles with Smiles

raproe

It's an English bike (I checked the VIN #) so it has English units.

But more seriously, as Skyblue62 says, we still use English units here. My shop uses them for all internal work because we think in English units and it is easy to see a problem and because it avoids errors from converting. When we publish for SAE, ASME or whatever, we convert to metric for the publication.

Before I started my own business, I was an engineer working on the International Space Station and Space Shuttle. NASA specified that we work in English units because US engineers (at least 20 years ago) think in English units. Combining units is what led to the Mars Observer fiasco.

When US engineers take the tests to register as professional engineers, they take one set of tests when they graduate and another after 4 years of practice. The first set of tests is in metric units and the second in English units.

Thats probably much more than you wanted to know.

Rich

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"....by its very nature, a single-tracker is in unstable equilibrium, i.e., it cannot, when stationary, stand up by itself."

SuperMan

Yep.
_

Skyblue62

Quote mglemans86 'If GOD wanted us to be metric he would have had 10 Apostles'

And if God had wanted us to be bi-linear he'd have given us 2 feet with 10 digits

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Ian