Head removal...and then replacing correctly

[Chip]

Folks:

I've got to remove the heads on my '96 1100RT (long story ...don't ask as it will raise my blood pressure). This job will probably push the edges of my mechanical ability. Anyway, finding TDC, removing the cam gear and hanging on to the chain makes sense to me. And if I was only going to remove and replace a single head, I think I'd be okay.

 

However...I need to remove both heads. While they are off, I'm taking 'em to a machine shop for inspection, and possible valve job (with over 100k, it seems to be the prudent thing to do).

 

To my point...and my questions:

1) After I pull the first head off; I think I'm supposed to rotate the crank until the other head is at tdc. Obviously, the chain on the first head is going to rotate. As long as I've marked everything on the gear and some point on the motor, do I only have to worry about loosing the timing chain? In other words, do I just use a tie wrap to hold it?

 

2) If I have to have a valve job done, what do I need to do to make sure the valves and rocker arms are in the proper position prior to reinstalling the head? In other words, is there something I need to understand to reinstall the rocker arms?

 

3) My current plan for reinstall includes replacing the head gaskets, inner gaskets, and valve cover gaskets. Outside of replacing a broken part (I'm sure I'll break something ), am I missing anything?

 

Again, although I'm willing to try just about anything, something tells me that it's not as simple as the Haynes manual says.

 

Thanks in advance.

[Ken H.]

Here’s what I do… There many be other ideas.

 

First, on the disassembled side mark the cam gear and the chain with a dab of paint.

 

Once I have the first side off I have a helper stick a screwdriver or whatever through the cam gear center and hold the gear taunt against the chain while I rotate the engine to get the other side into position. Then I re-tie up the gear up to chain.

 

The issue you need to be careful of is not so much the cam gear jumping on the chain as the chain jumping on the intermediate shaft deep in the engine. But later after the second side is back together and you need to rotate again (doing the same deal) the paint markings will help confirm that indeed all stayed in place.

 

[Ken H.]

Oh, guess I didn’t answer #2 – There is nothing special you need to do. The cam has an index tab to the chain, and as long as that is correctly mated, there is only one way for it to go together with the cylinder you are working on at TDC.

 

#3 – Be aware that the cam chain guides don’t slip away to the inside. Consider installing the updated cam chain tensioner assembly as long as your there. Know and follow the correct head bolt nut torqueing sequence. Including the 600 mile follow up. That’s about all I can think of at the moment.

 

[Boffin]

Also be sure you only turn the engine in its correct direction - turning it backward is likely to break the cam chain guides Replacing these requires splitting the crank-cases which you do not want to do.

 

Andy

[Anton Largiader]

Once I have the first side off I have a helper stick a screwdriver or whatever through the cam gear center and hold the gear taunt against the chain while I rotate the engine to get the other side into position.

 

For me this is only comes up on assembly (I'll just remove both heads with one at overlap and straighten it all out once the cam is removed) but I often use this technique when reassembling. I just thread the bolt halfway in and leave the sprocket hanging on that. With the tensioner out or partially out, there's not much force on the bolt threads.

 

There are a lot of little tricks to doing all of this that can't be easily communicated this way. Make sure you have a complete understanding of what correct assembly is, and make sure you achieve it without smacking the piston into any open valves. It'll take you longer than it takes some of us, but that's really no big deal.

[Dave Faria]

 

 

I've not pulled the heads on my bike and hope I don't have too but, just reading. Is it possible to damage(stretch) the cam chain while breaking loose or tightening the cam bolt that holds the sproket to the cam?? How is this done at the factory??? Does the factory have a jig that locks the cam sproket in place??

[Chip]

(I'll just remove both heads with one at overlap and straighten it all out once the cam is removed)

 

Can you help me understand this (i.e. "overlap")? It sounds like I just get one side at tdc, remove the cam sprocket & support the chain and remove the head. Then, I just do the same on the other side sans the crank rotation to tdc. In other words, it's only on reassembly that I need to get the pistons at tdc (to, among other things, make sure I don't damage valves). Is this correct?

 

If so, what about the head with the overlap? If I then remove rocker arms (in preparation to do a valve job), isn't there going to be some tension on the valve springs? Is this just a "make sure you don't have a valve spring go flying type of a problem"?

 

I'll probably do the tdc during removal of both heads but I do want to know what to *really* worry about vs just different ways to do stuff.

 

So far, the key "don't do this part wrong" issues are:

a) rotate crank in correct direction to tdc at compression stroke.

b) mark cam sprocket and chain with paint so they can be realigned.

c) don't let cam sprocket fall into case

d) don't let cam chain jump teeth on inner crank gear

e) On reassembly, valves must be closed & cam sprocket and chain must be aligned to prevent valve damage and maintain timing

f) torque everything in order & according to specs

 

[Anton Largiader]

I can't really describe what I do because I probably look for, visualize and verify more things than I can remember to list. And it's not always the same because sometimes I'm starting from nothing (after splitting the cases) and sometimes it's simply a head R&R. R259 head installation is one of the few things I try to refrain from writing about.

 

You should probably follow a clear step-by-step. A guy named Steptoe has a decent description on the UKGSer site, and I think it's also posted on ADVRider.