Help removing cylinder heads

[Milk Tray Man]

Hi folks,

Some advice please...

I need to remove the cylinder heads as the stud bolts are badly corroded and one has broken off leaving a piece still in the head. I have a friend who can fix that but need to remove the heads and am having a problem loosening the bolts in the camshaft sprocket. Have tried muscle power, air gun and before get serious is their a knack, special tool or technique for loosening off these bolts?

Thanks in advance for any advice.

Cheer

Glen

 

[Timolgra]

Try using a hot air gun, they may well be 'Loctited'.

 

[Noddy]

Steppers has kindly put a stickie in the Font of all wisdom section re cylinder head removal. May just pay you to have a read. They are bloody tight though, I had to use a large knuckle bar with a pipe over the end.

 

[Milk Tray Man]

Sorted

Thanks for the help guys and the heads are now off. Just have to remember how to put the bike back together again now

 

[Timolgra]

Thanks for the help guys and the heads are now off. Just have to remember how to put the bike back together again now

Were the bolts holding the cam shaft gear loctited?

 

[DrFarkoff]

Thanks for the help guys and the heads are now off. Just have to remember how to put the bike back together again now

Did you cable tie the sprockets to the chain and keep some tension on them????????

Be carefull when you rebuild if you didn't I had 2 head to replace under warranty on an R850GS we could never get the timing marks right (including the foreman of 25 years BMW experience!)
if you have the same problem Lag the valve timing Don't lead it! it "just" clunks the piston prior to tdc!!!

 

[(RIP) ugg]

Hi folks,

Some advice please...

I need to remove the cylinder heads as the stud bolts are badly corroded and one has broken off leaving a piece still in the head. I have a friend who can fix that but need to remove the heads and am having a problem loosening the bolts in the camshaft sprocket. Have tried muscle power, air gun and before get serious is their a knack, special tool or technique for loosening off these bolts?

Thanks in advance for any advice.

Cheer

Glen

dum,de

 

[Paul Young]

If it's exhaust studs that are broken, I repaired mine in situ, rather than dismantle the heads. A Dremel, a small drill bit & a thread tap were all that was neded for most of them. One needed a helicoil & that was just as easy to do.

Use the Dremel to cut any remaining tip of the stud flat. Use small drill to drill down into the stud, as if you were going to used an extractor & then use the Dremel with a tungsten carbide bit (like an arbour but with a thread running up/down its length) to open up the hole you drilled. Once you're near to the outer edge of the stud, use the thread tap to clear out the remains.

Worst case scenario is that you ruin the threads, so use a helicoil kit to repair them. It took less time to do all six studs than it would have taken me to remove & replace one c/head.

HTH,

 

[johnhorsley5]

What length of exhaust stud?

Although this is an old post, it's appropriate rather than start a new one.
I had the local workshop remove the studs on the left head. I supplied them with 40mm Stainless studs, but I think there is too much exposed.
Does anyone know how long the exposed section should be? (to save me measuring it)

 

[MattW]

Although this is an old post, it's appropriate rather than start a new one.
I had the local workshop remove the studs on the left head. I supplied them with 40mm Stainless studs, but I think there is too much exposed.
Does anyone know how long the exposed section should be? (to save me measuring it)

According to http://www.maxbmwmotorcycles.com/fiche/DiagramsMain.aspx?vid=51668&rnd=03252011 they're M8x40 - I don't know what the exposed length should be though - didn't really matter to me when I changed mine as I used standard brass nuts rather than the OEM dome nuts.

You could remove one of the studs (lock two nuts onto it) and probe down the drilling in the head to see how deep it is?...

 

[roadrunnert509]

Out of my league....

 

[johnhorsley5]

Thanks Guys.
My concern was that the workshop had not screwed the studs in far enough and they might strip out, but I think it's OK.
If necessary I could pad it out with washers