Repairing cylinder head bolts - G80S
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Repairing cylinder head bolts - G80S
My G80S doesn't have the correct too bolts to accommodate the engine stay, I've got a new set of bolts to go on but I can't figure out a way of replacing them without removing the whole engine.... there must be something I'm missing here!!!
Last edited by markwhitelock on Sun May 03, 2020 3:04 pm, edited 1 time in total.
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Re: Removing cylinder head bolts - G80S
I think you have to take out all the bolts. Then you can tilt the rocker box and get those ones out. Means you have to remake the gasket seal, reset the tappets etc. The oversize hole shouldn't be a problem, the angle plate can be drilled out, after checking there will still be space to turn the bolt. You might be lucky if the new thread and a helicoil are close enough to tap and fit the helicoil while the rocker box is off. Looks like space is at a premium and it might not be the same pitch so that would be a matter of careful measurement and luck before you try it.
Stan
Stan
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Re: Removing cylinder head bolts - G80S
Hi
I think you have to remove the rest of the rocker box bolts so as you can tilt the box to remove/fit the center two.
Regards Mick
I think you have to remove the rest of the rocker box bolts so as you can tilt the box to remove/fit the center two.
Regards Mick
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Re: Removing cylinder head bolts - G80S
Get a bolt made to suit your thread and retain the steady.markwhitelock wrote:What other options do I have?
Regards Mick
- ajscomboman
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Re: Removing cylinder head bolts - G80S
Mark as you have found out, you do have to remove the rocker box bolts and tip it to one side to both fit and remove the headsteady bolts and also the very rear one can be a pig! As for options, well you could cut down your existing bolt and then wind it in with high strength threadlock, then redrill it to 5/16th BSF. However that is best done off the bike and with some good equipment.
As for your crankcase drain plug, I thought about this and decided that your engine is a mix of years. The stamped half must be the original 56 case but the other half with the drain plug must be earlier with the smaller 1/4" BSP thread.
As for your crankcase drain plug, I thought about this and decided that your engine is a mix of years. The stamped half must be the original 56 case but the other half with the drain plug must be earlier with the smaller 1/4" BSP thread.
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Re: Removing cylinder head bolts - G80S
Yes, that makes sense. Hopefully there aren't many other surprises for me!!ajscomboman wrote:As for your crankcase drain plug, I thought about this and decided that your engine is a mix of years. The stamped half must be the original 56 case but the other half with the drain plug must be earlier with the smaller 1/4" BSP thread.
Do you have the right tools to do that fix with the bolts, Rob? I could get the bolts out and over to you...
I haven't changed the final two bolts as I didn't want to disturb the rocker box and tappets, but I can do if I find someone willing to adapt the bolts for the headsteady.
- ajscomboman
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Re: Removing cylinder head bolts - G80S
I would have taken it to the local engineering company but sadly that is no longer trading, my mate has moved to Portsmouth and with lockdown I can't get to him.markwhitelock wrote:Yes, that makes sense. Hopefully there aren't many other surprises for me!!ajscomboman wrote:As for your crankcase drain plug, I thought about this and decided that your engine is a mix of years. The stamped half must be the original 56 case but the other half with the drain plug must be earlier with the smaller 1/4" BSP thread.
Do you have the right tools to do that fix with the bolts, Rob? I could get the bolts out and over to you...
I haven't changed the final two bolts as I didn't want to disturb the rocker box and tappets, but I can do if I find someone willing to adapt the bolts for the headsteady.
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Re: Removing cylinder head bolts - G80S
Mark, if you do remove the rocker cover be sure to dig any crud (usually old gasket material scrapings) out of the bottom of the blind bolt holes in the head.
It commonly happens that in trying to cure an oil leak 'twixt cover and (alloy) head folk keep tightening the cover bolts until one or more of the thread(s) strip because instead of compressing the gasket the bolt(s) has bottomed out on the crud.
It commonly happens that in trying to cure an oil leak 'twixt cover and (alloy) head folk keep tightening the cover bolts until one or more of the thread(s) strip because instead of compressing the gasket the bolt(s) has bottomed out on the crud.
'There is a tide in the affairs of men
Which taken at the flood............'
Which taken at the flood............'
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Re: Removing cylinder head bolts - G80S
Good tip, I did notice some of them felt quite cruddy as I replaced the individual bolts I could.SPRIDDLER wrote:Mark, if you do remove the rocker cover be sure to dig any crud (usually old gasket material scrapings) out of the bottom of the blind bolt holes in the head.
It commonly happens that in trying to cure an oil leak 'twixt cover and (alloy) head folk keep tightening the cover bolts until one or more of the thread(s) strip because instead of compressing the gasket the bolt(s) has bottomed out on the crud.