Classic Triumph Bonneville

[Nidge]

That doesn’t sound right at all - with plugs out (e.g. when setting tappers) mine is very easy to turn over by hand. Is it uniformly resistant or does it vary?

[Count Steer]

That doesn’t sound right at all

There's a more technical term for what it sounds like. Something sounds utterly bollixed.

[Hairybiker84]

Primary drive chain not too tight? How is the face of the tensioner? It's more than 40 years since I've played with these! 500 Tiger 100ss and 650 pre unit Triton.
I don't remember them being terribly difficult to bump either and I only weighed about 10 stone then!

[Nidge]

Just a thought, when you pull the clutch in the kickstart does swing freely?

[Nidge]

And another thought- does it turn over properly with the primary case removed?

[Mr. Dazzle]

I had to turn the engine over via the primary drive when refitting the clutch. Well I didn't have, but it's an inevitably consequence of doing the nut up. It turned over OK then. It turned over a piece of piss (via the rear wheel) before I put the head on, which may be telling.

If you pull the clutch the kickstart swings free, after some initial untick/resistance. Once it's free you can pump the lever very easily.

Primary chain was just adjusted to the workshop manual specified freeplay - can't remember exactly what it was, but 3/8" sounds familiar. The primary case isn't really on at the moment anyway, it's just on loosely while I wait for the right gasket.

It's hard to tell if it's uniformly hard to turn over 'cause I'm pushing pretty hard. It varies a bit I think.

[David]

That doesn’t sound right at all - with plugs out (e.g. when setting tappers) mine is very easy to turn over by hand. Is it uniformly resistant or does it vary?

It's been rebuilt.....might be just a bit tight.

[Mr. Dazzle]

That doesn’t sound right at all - with plugs out (e.g. when setting tappers) mine is very easy to turn over by hand. Is it uniformly resistant or does it vary?

It's been rebuilt.....might be just a bit tight.

Well yeah part of me thinks that too - if I could just get it going it'd loosen up

Before the rebuild I managed to start it (hot) at a set of lights while sat on it, it seemed much easier then even allowing for the 11:1s.

[Nidge]

Well you can put the gearbox cover back on - if the kicker swings freely with the clutch pulled in then the problem isn’t in there. I think I’d be tempted to take the primary off and see what’s going on as you kick it over (with the plugs out )

[Mr. Dazzle]

I did that loads as part of my clutch adjustment - or are you referring to something else?

When you kick it things go around If you kick it with the clutch lever pulled things go around nicely, if you do it with the lever not pulled it's hard work.

[Nidge]

But it could kick freely with the plugs out then?

[Mr. Dazzle]

No, I don't think it did.

Freer than when the plugs are in, but not easy.

[JackyJoll]

It turned over a piece of piss (via the rear wheel) before I put the head on

I don’t like the sound of that, but I’m not understanding what is jammed. Turning the engine over by the nut on the mainshaft is a bit stiff, because the primary is geared 1:2.

Can the engine be turned by the nut on the crankshaft? You must have turned it over to set the valve clearances. And people always see if an assembled engine turns yes?

[Mr. Dazzle]

Yeah turned it over via the crank nut too, that's much easier cause there's no ratio as you say.

I must have turned it over a million times when putting the rockers back on cause it took me 50 attempts to get the pushrods in the right place. Then again when I did the clearances.

I do seem to recall it got a bit harder after torquing the head down but before doing the clearances. I might be wrong there though.

Not sure what's changed since then. New clutch....pretty much it.

[Count Steer]

Time for a recap.
Ignoring the slightly tired kick-start toothed cam thing.
You can turn it over easily eg with the back wheel with the head off?
It's not easy but not bad with the head on and plugs out?
It's nigh on impossible with the head on and plugs in?
It didn't used to be so difficult with the same pistons etc until you did.......
1.....?
2.....?
3 Put a new clutch in.

Tight engine but it 'spins' ok with the head off? Umm.

[Count Steer]

Am I reading that right? You set the valve clearances and then torqued the head down???? Edit. No I'm not. Ignore.

[Mr. Dazzle]

No, othet way around.

I had to turn it over loads while juggling to get the push rods mated with the rockers. Mostly just rocking back and forth and feeling to see things were moving as they should.

Then I torqued it down, then I turned it over loads more to do the valves.

[JackyJoll]

If you pull the clutch the kickstart swings free, after some initial untick/resistance. Once it's free you can pump the lever very easily.

So everything turns as normal, except the clutch basket, the primary chain, the alternator rotor and the engine.

I’m sure you have some idea how stiff an engine with no plugs in should feel.

The clutch plates and springs only clamp the basket to the centre and the centre does turn. You would know if the basket or chain was fouling the case.

[Mr. Dazzle]

Just been and checked to confirm what I've been saying is true.

With the primary case off and the plugs out I can turn the engine over with the crank nut OK. It turns over fine using one hand and a ratchet driver about 8" long. There's a strong hiss from the case breather ports as the pistons come down and you can feel the air coming from the plug holes. You can see the valves moving too.

With the plugs in its distinctly harder to turn over using the same method.

With the plugs out its hard to turn over using the kick. Even with plugs out I have to bounce on the lever to get it started, after that I can just about keep it going with leg power alone. With the plugs in its correspondingly harder, but still doable.

[Count Steer]

It sounds like the kick-start gearing is jammming/binding somehow. I'd be inclined to get it back together and bump start it (but the fact that you can't turn it over with the back wheel is a bit odd considering all that you've described). You'll need a willing pusher rather than run and hop on.
Just see if it runs and listen to it. Then try and work out if the kick start mechanism needs treatment.
If you got it popping and banging a bit can you check the timing?