Changing a cylinder head gasket.
The pictures are an 1100 GS, but the only difference between the 1100 & 1150 is in the exhaust down pipe fixings to the cylinder head –
The 1100 have three bolts per side (that are normally seized and you can guarantee at least one will snap off), and the 1150 have only two per side, that you shouldn’t have any problem removing.
You don’t have to remove the tank, or any other bodywork, but I’d suggest spraying penetrating oil or something similar onto the exhaust bolts a few days before. Also have a new set of exhaust studs and nuts to hand.
The exhaust bolts. If they’re badly corroded and flaking, hit a smaller seized socket onto them. The socket size depends on how badly corroded the nuts are. Start with a 13mm, then work your way down to a 11mm if need be.
Here’s one that snapped.
You have to remove both downpipes on an 1100, and you can get away with only removing one side on an 1150, but you’ll find it so much easier taking both off.
I use an old broken airhead exhaust spanner to knock the pipes out of the head.
Here’s the head with the down pipes removed.
All the work shown, is being done on the right had cylinder head. It’s all the same as the left hand except the cam chain tensioned is on the bottom on the right hand side, but on the top on the left hand side.
Remove the throttle body from the head.
Remove the rocker covers, and get the side your working on to TDC. Remove the cam sprocket cover.
Put the bike in gear, hold the rear brake on, and crack the sprocket cap nut loose (don’t undo it more than a turn), it’s an 8mm allen head bolt
Now the important part.
Thread a small cable tie through a hole in the sprocket, and around the timing chain. Remember, you’ve loosened the sprocket, so you can move it away slightly from the head, giving you some space to get the cable tie out from behind the sprocket.
Pull the cable tie tight, so the chain can’t fall from the sprocket.
Now remove the two lower allen headed bolts ( 5 mm heads)
And remove the four cylinder head bolts ( 15mm hex head) . Three are obvious.
And one partly hidden underneath
.
Looking near the cam sprocket, you’ll see a an allen bolt, this also need to be removed ( 8mm head) .
Bolt removed
Now remove the cam sprocket bolt completly.
And undo and remove the cam chain tensioner ( underneath the cylinder)
Pop the sprocket off the cam end, and looking down where the cam chain goes, you’ll see a small allen head bolt
You need the sprocket off to allow you to undo the small allen bolt , which is a 5mm head. And you’ll need an extension bar as shown.
.
That’s all the bolts removed that hold the head in place - you’ve no need to remove any of the bolts that hold the rocker gear in place. They all stay in place on the head.
Now you just pull the head off, it may need a bit of gentle persuasion with a rubber hammer type object ; ) .
Taking care that the cam sprocket goes down the tunnel as you remove the head
And what it should look like when the heads removed .
.
Clean the surfaces of any old gaskets and dirt.
The new gasket is 3 layered, they’ve been like this since 98, so if your replacing an earlier model, don’t worry if it’s different to the one you’ve taken off .
.
Place the new gasket onto the cylinder.
And fit the head back onto the studs, making sure the cam sprocket and chain is pulled through the head. Do the cylinder head nuts and all the other bolts up to the correct torque.
Now the fiddly bit, and the part that needs to be done correctly or else you’ll have a bike that woun’t start, or worse, an expensive bill .
On the cam, you’ll notice an index slot. This can be moved a few degrees either way, don’t worry if it moves, it’s not going to alter the valve timing.
And on the sprocket, you’ll see the locating tab (shown in the pictures before the head went back on,so it could be seen clearly.
Now, you’ve got to locate the sprocket onto the cam, with the tab fitting into the index slot. You can move the cam a small amount to kelp locate it. THAT’S WHY WE CABLE TIED THE CHAIN TO THE SPROCKET. So the valve timing will be the same.
When it’s fully located in place (take your time and make completely sure it all located and in place properly), do the sprocket nut up finger tight and cut off the cable tie. And replace the cam chain tensioner.
NOW TURN THE ENGINE OVER BY HAND, ( with the bike in gear, turn the back wheel to revolve the engine). Try doing the same before starting the job, so you’ll know what it feels like, and have something to compare.
It should turn the same as before you started the job.
If it doesn’t turn fully, and you can’t turn the engine, it means you haven’t located the sprocket onto the cam properly.
Just turn the engine back to TDC, cable tie the chain to the sprocket and try again until it's right . But if you can’t turn the engine over by hand don’t even think about starting it up. Just keep on locating the cam and sprocket until you can
The job is now done, you’ve just to replace all the parts removed and check the valve clearences .
If you’ve snapped a couple of exhaust studs, don’t worry , they’re lots of bikes out there riding around with only one stud on each side, and they don’t have any problems .
The pictures are an 1100 GS, but the only difference between the 1100 & 1150 is in the exhaust down pipe fixings to the cylinder head –
The 1100 have three bolts per side (that are normally seized and you can guarantee at least one will snap off), and the 1150 have only two per side, that you shouldn’t have any problem removing.
You don’t have to remove the tank, or any other bodywork, but I’d suggest spraying penetrating oil or something similar onto the exhaust bolts a few days before. Also have a new set of exhaust studs and nuts to hand.
The exhaust bolts. If they’re badly corroded and flaking, hit a smaller seized socket onto them. The socket size depends on how badly corroded the nuts are. Start with a 13mm, then work your way down to a 11mm if need be.
Here’s one that snapped.
You have to remove both downpipes on an 1100, and you can get away with only removing one side on an 1150, but you’ll find it so much easier taking both off.
I use an old broken airhead exhaust spanner to knock the pipes out of the head.
Here’s the head with the down pipes removed.
All the work shown, is being done on the right had cylinder head. It’s all the same as the left hand except the cam chain tensioned is on the bottom on the right hand side, but on the top on the left hand side.
Remove the throttle body from the head.
Remove the rocker covers, and get the side your working on to TDC. Remove the cam sprocket cover.
Put the bike in gear, hold the rear brake on, and crack the sprocket cap nut loose (don’t undo it more than a turn), it’s an 8mm allen head bolt
Now the important part.
Thread a small cable tie through a hole in the sprocket, and around the timing chain. Remember, you’ve loosened the sprocket, so you can move it away slightly from the head, giving you some space to get the cable tie out from behind the sprocket.
Pull the cable tie tight, so the chain can’t fall from the sprocket.
Now remove the two lower allen headed bolts ( 5 mm heads)
And remove the four cylinder head bolts ( 15mm hex head) . Three are obvious.
And one partly hidden underneath
.Looking near the cam sprocket, you’ll see a an allen bolt, this also need to be removed ( 8mm head) .
Bolt removed
Now remove the cam sprocket bolt completly.
And undo and remove the cam chain tensioner ( underneath the cylinder)
Pop the sprocket off the cam end, and looking down where the cam chain goes, you’ll see a small allen head bolt
You need the sprocket off to allow you to undo the small allen bolt , which is a 5mm head. And you’ll need an extension bar as shown.
. That’s all the bolts removed that hold the head in place - you’ve no need to remove any of the bolts that hold the rocker gear in place. They all stay in place on the head.
Now you just pull the head off, it may need a bit of gentle persuasion with a rubber hammer type object ; ) .
Taking care that the cam sprocket goes down the tunnel as you remove the head
And what it should look like when the heads removed .
.Clean the surfaces of any old gaskets and dirt.
The new gasket is 3 layered, they’ve been like this since 98, so if your replacing an earlier model, don’t worry if it’s different to the one you’ve taken off .
.Place the new gasket onto the cylinder.
And fit the head back onto the studs, making sure the cam sprocket and chain is pulled through the head. Do the cylinder head nuts and all the other bolts up to the correct torque.
Now the fiddly bit, and the part that needs to be done correctly or else you’ll have a bike that woun’t start, or worse, an expensive bill .
On the cam, you’ll notice an index slot. This can be moved a few degrees either way, don’t worry if it moves, it’s not going to alter the valve timing.
And on the sprocket, you’ll see the locating tab (shown in the pictures before the head went back on,so it could be seen clearly.
Now, you’ve got to locate the sprocket onto the cam, with the tab fitting into the index slot. You can move the cam a small amount to kelp locate it. THAT’S WHY WE CABLE TIED THE CHAIN TO THE SPROCKET. So the valve timing will be the same.
When it’s fully located in place (take your time and make completely sure it all located and in place properly), do the sprocket nut up finger tight and cut off the cable tie. And replace the cam chain tensioner.
NOW TURN THE ENGINE OVER BY HAND, ( with the bike in gear, turn the back wheel to revolve the engine). Try doing the same before starting the job, so you’ll know what it feels like, and have something to compare.
It should turn the same as before you started the job.
If it doesn’t turn fully, and you can’t turn the engine, it means you haven’t located the sprocket onto the cam properly.
Just turn the engine back to TDC, cable tie the chain to the sprocket and try again until it's right . But if you can’t turn the engine over by hand don’t even think about starting it up. Just keep on locating the cam and sprocket until you can
The job is now done, you’ve just to replace all the parts removed and check the valve clearences .
If you’ve snapped a couple of exhaust studs, don’t worry , they’re lots of bikes out there riding around with only one stud on each side, and they don’t have any problems .
