2008 GSA timing adjustment?

[magic dave]

Hi. I'm no mechanic so I'm asking this verbatim from my mechanic and fellow biker friend.
We decided to change the right hand chain tensioner as I have just done the left one and thought it wouldn't hurt. Mistake. Looks like someone had been there before, had trouble, and fitted a helicoil. That's now damaged getting the tensioner out. So head off, barrel off, went to an engineer shop and he's made a new sleeve with a hole that lines up for oil flow. I would point out that the sleeve runs the length of the tensioner, so the space between the tensioner below the thread and the side of the barrel is reduced.
Put it all back together and that cylinder will not run properly. By disconnecting the left coils I've determined that it is actually firing, but only under some throttle and very lumpy. It feels and sounds like it's massively out of time. Can you change the timing on one side? The chain was zip tied to the cam gear and the cam gear has a notch to locate it on the end of the camshaft. With the cylinder at TDC and the valves closed (adjusters loose) and the locating pin in the back of the flywheel the cam sensor is at 9 o clock and the arrow on the gear is 3 o clock as per the manual.
As far as I can see the engine is in time. So there's 3 scenarios that are possible I think?

1. It's not in time and there's an adjustment I haven't found.
2. The reduced space around the bottom of the tensioner is reducing oil flow to the plunger - would that put the chain out of time?
3. There's a piston ring that hasn't gone on properly and it's losing compression?

I'm pretty desperate. Spent days chasing myself in circles. Thanks for any thoughts.

 

[botus]

the ignition timing is not adjustable (the engine management does it all)

you can reassemble with the Valve timing wrong and it will run badly - if you get it very wrong, you could bend a valve and if it even runs it will be really awful, and worse you can damage a bearing (and the piston) as the piston hits the valve

pull off both valve covers, recheck valve timing on both cylinders (and re set if wrong), from the sounds of it, also check valve opening and closing and valve clearances too - then double check the cam and cranks position sensors are plugged in and you didn't forget the fuel injectors. Then do a compression test - and see where you are

chains under tension open valves - the tensioner is ALWAYS on the other "slack" side - so don't impact valve timing. Thus unless the chain is seriously stretched it'll be wrong because the initial set up was wrong

......did someone bend a valve resting the cyl head on its face, when a valve was open ? head off, cams out, plugs in, fluid should sit in the chamber not seep away and out the ports... you could have the same leak with a burnt valve / heavily worn seats

 

[Steptoe]

Before going in too deep check the throttle cable is fully seated at both the throttle body end and the junction box, and that the throttle cable pulley is against its stop.

 

[magic dave]

the ignition timing is not adjustable (the engine management does it all)

you can reassemble with the Valve timing wrong and it will run badly - if you get it very wrong, you could bend a valve and if it even runs it will be really awful, and worse you can damage a bearing (and the piston) as the piston hits the valve

pull off both valve covers, recheck valve timing on both cylinders (and re set if wrong), from the sounds of it, also check valve opening and closing and valve clearances too - then double check the cam and cranks position sensors are plugged in and you didn't forget the fuel injectors. Then do a compression test - and see where you are

chains under tension open valves - the tensioner is ALWAYS on the other "slack" side - so don't impact valve timing. Thus unless the chain is seriously stretched it'll be wrong because the initial set up was wrong

......did someone bend a valve resting the cyl head on its face, when a valve was open ? head off, cams out, plugs in, fluid should sit in the chamber not seep away and out the ports... you could have the same leak with a burnt valve / heavily worn seats

Thanks for this. Everything was running before we went for the tensioner change. How can you reassemble with the valve timing wrong if the cam gear was tied to the chain, head was removed at TDC with valves closed (so no valve damage), the cam shaft cog is notched and all put back together with cylinder head at the top? Is there something we've missed?
One question to double check the valve order. The left and right valves open alternately? cylinders at the top, left hand valves open. Turn the engine, at next cycle of cylinders at the top, right hand valves open. That's correct??
Injectors are working, spraying fuel. Plugs are sparking, checked by holding against the rocker cover bolt.
What are your thoughts about this sleeve the engineer has made?
Compression test is next. My hunch is piston ring didn't seat properly when it was put back in the barrel. Is that even possible?
thanks!!

 

[magic dave]

Before going in too deep check the throttle cable is fully seated at both the throttle body end and the junction box, and that the throttle cable pulley is against its stop.

I'll check, thanks

the ignition timing is not adjustable (the engine management does it all)

you can reassemble with the Valve timing wrong and it will run badly - if you get it very wrong, you could bend a valve and if it even runs it will be really awful, and worse you can damage a bearing (and the piston) as the piston hits the valve

pull off both valve covers, recheck valve timing on both cylinders (and re set if wrong), from the sounds of it, also check valve opening and closing and valve clearances too - then double check the cam and cranks position sensors are plugged in and you didn't forget the fuel injectors. Then do a compression test - and see where you are

chains under tension open valves - the tensioner is ALWAYS on the other "slack" side - so don't impact valve timing. Thus unless the chain is seriously stretched it'll be wrong because the initial set up was wrong

......did someone bend a valve resting the cyl head on its face, when a valve was open ? head off, cams out, plugs in, fluid should sit in the chamber not seep away and out the ports... you could have the same leak with a burnt valve / heavily worn seats

I've got good news!! It was the throttle cable. Must has been caught on something somewhere as the butterfly was a quarter open!! All sorted and now that side is running.
BUT. Now the right side chain is rattling when it gets warm and it wasn't before. Someone is saying there should be a rubber seal inside the tensioner where the plunger goes in? Is that right?
thanks again

 

[Steptoe]

I'll check, thanks

I've got good news!! It was the throttle cable. Must has been caught on something somewhere as the butterfly was a quarter open!! All sorted and now that side is running.
BUT. Now the right side chain is rattling when it gets warm and it wasn't before. Someone is saying there should be a rubber seal inside the tensioner where the plunger goes in? Is that right?
thanks again

. Here to help
Nearly every 1200 engine I’ve rebuilt or had to remove the cylinders (a 1200S just last week) has needed the throttle cables reseated before starting them up. Usually the outer cable jumps out of the junction box, simply pull the cable around while twisting the throttle snaps it back into place. Afraid I can’t help regarding the R/H tensioner noise as to the unusual work that’s been undertaken on it.,

 

[botus]

I have to say I wasn't keen on the 'sound' of the engineering work... why not get secondhand parts if your budget is tight ?

wow in the UK too - should be easy peasy

 

[Pukmeister]

I would be tempted to remove the RH rocker cover and inspect the tensioner and blade via the cam chain tunnel to see if the blade has broken.

 

[magic dave]

I have to say I wasn't keen on the 'sound' of the engineering work... why not get secondhand parts if your budget is tight ?

wow in the UK too - should be easy peasy

Because a mechanic told me I should change both barrels and both pistons.

 

[magic dave]

. Here to help
Nearly every 1200 engine I’ve rebuilt or had to remove the cylinders (a 1200S just last week) has needed the throttle cables reseated before starting them up. Usually the outer cable jumps out of the junction box, simply pull the cable around while twisting the throttle snaps it back into place. Afraid I can’t help regarding the R/H tensioner noise as to the unusual work that’s been undertaken on it.,

turned out that the new sleeve wasn't 100% flush so I wasntightening it too much to get it to stop dripping. Took it back out, used a small fine file to get it flush, put the tensioner back in to the correct setting and all is good now. No rattle and no drip.