79 GS750 Cylinder Head Stuck

[sam5534]

Hi Guys,

I am beginning a top end rebuild of a 79 GS750 that i purchased recently.

I have been following the service manual and have removed the cylinder head. The manual states that the next step is to remove the cylinder block but it doesn't mention any more bolts to remove to do this.

Following the above steps i can't seem to get it to budge. I have hit it for the past hour with a rubber mallet trying to knock it loose.

I found a Q&A on this site with a similar query the provided answer was as follows:

REPLY: Malcolm Evans
Sounds like you've missed a bolt. Have a look at the front of the block for one M6 bolt which is upside down, right in the centre.

I have looked all over the block and can't seem to find any further bolts securing the cylinder block.

I have had a look through this forum and cant seem to find anything regarding this problem either.

Any help wold be hugely appreciated as this is put a major hold on the project.

[Steve]

That little bolt is at the TOP of the block, and connects to the head. Since the head is already off, we can assume that the bolt is not there.

Your "stuck" cylinder block has nothing holding it except the tenacity of the base gasket. Be very careful trying to pry on any of the fins, they will break easily. See if there is a reinforced pry point that is low, around the edge somewhere. Not sure about your particular model, but some bikes have locating dowels in a couple of corners, which will require you to lift straight UP for the first 10mm or so. Rocking very far in either direction will only put them in a bind, so try to lift as straight as possible.

.

[sam5534]

Hi Steve,

Thanks for your reply.

There has been locating dowels in the cylinder head so i guess it is safe to assume they will be in the block as well.

I have had a look for any pry points but cant find any.

I have just had another try and was lifting the whole engine off the ground by the cylinder block.

Based on the i don't think i will be able to remove from pulling alone.

[Agemax]

try squirting some penetrating oil down the holes in the block, where the studs go through. they may be corroded and full of crud.leave to soak in for an hour or two

[sam5534]

Hmmm.

I only have WD40 at the minute and it's now 12:08am. I'll spray some of that down there now and pick up some proper penetrating oil tomorrow.

[MisterCinders]

It took me several attempts to pull the block on my bike last year, these ultimately worked to liberate it from the old base gasket.

Penetrating oil down the stud holes.

PB blaster around the edges of the block.

Use a block of wood to buffer, and keep hammering from the sides of the block to break the grip. Even with the block, make sure to hammer the sides squarely to avoid breaking fins.

Once you get any vertical movement, get some flat head drivers and pry bars to work around the seam and coax that block free. You don't need a lot of leverage on one spot, just a spacer to maintain progress as you work around the edge.

[Nessism]

If you stick a screwdriver between the seam then you could mar the gasket surfaces.

If you hammer upwards on the cylinder block make sure to only do so in the areas where the fins are joined together, otherwise you could break off some fins.

[MisterCinders]

If you stick a screwdriver between the seam then you could mar the gasket surfaces.

If you hammer upwards on the cylinder block make sure to only do so in the areas where the fins are joined together, otherwise you could break off some fins.

Ed speaks truth. That's why the prybars/screwdrivers are just spacers to maintain progress as you pull the block. Don't use them to actually lever the thing up. I found that, as the gasket began to free up, the spacers would keep the block from sticking back to the base.

[stucknarut]

I just did this and it's a PITA. I hammered with a block of wood and a deadblow hammer until it came free. If you can find a plastic wedge that might work to split it too. And yeah, the gasket surface mars really, really easily with a steel screwdriver, don't even pry a little. Also the guys on here told me not to use the el cheapo green paper gaskets I got on ebay. I should've listened to them.