Dreaded project

Looks like I am going to be forced into replacing the carb boots on my Seca. Mucho cracks and tiny bubbles when idling. One of the many things I have picked up on this site is that this is a serious danger zone, due to the risk of breaking off one or more of the bolts into the head. I doubt they have ever been removed and I am wondering if there is any technique that has been tried to reduce or eliminate this problem. How about having the engine hot, for example? Doesn't look like you could get penetrating oil in there enough to do any good. Does anyone know how much torque you can apply to these bolts before they like to snap?

 

It will depend on the condition of the bolt. I replaced mine on my XJ1100 when I had the carbs tore down and it wasn't hard at all to get the old ones out. I used SS hex bolts for the replacements.

 

Here's the Problem.

The Stock Cap Screws holding-on the Manifolds are cheap, soft steel.
Sometimes they come out without any problem at all.

The stuck ones are another story.
They ACT like they are turning out ... but, what is really happening is that the Cap Screw is twisting.
Feeling like you extracting the fastener, you keep applying undo torque until: "Snap" ... and the fastener is broken-off in the Head.

Heat isn't a good option because they are not a hardened fastener that can withstand the heat. The Heat just makes them all the more vulnerable to being twisted.

Impact is always good.
But, the available space to place the tool and the limited space to swing a hammer negates the effort.

I use a modified form of Impact.

I load an Allen-head Bit on a 1/2" Drive Ratchet Handle and hold steady and firm undo torque on the Ratchet Handle.
Then, I swat the Ratchet Handle with a hard wood Hammer Handle.

I have been lucky.
There are still three of them on the Manifolds of my 750 that are stuck ...
So, ... I just leave them be.

If you absolutely have to remove the Cap Screws and the Manifolds that your are replacing are going to be scrapped ...

I'd use a Dremel Tool with a Cut-Off Wafer and remove the Heads of the OEM Cap Screws to be able to remove the Manifold and work close to the Head.

That way you can heat the area surrounding the Cap Screw in the Head
Shoot some PB Blaster right close to the Head
Grab hold of the fastener with a mini-pipe wrench and hope you win the battle.

You might even try heating the remaining fastener stud to cherry red and letting it cool some before applying undo force.

About the only good news there is on the fasteners is:
They are soft.
In a pinch you'll be able to drill them out with ease.

 

It would be cool if this site had a comprehensive search index that would nail the topic in the archives every time.
Try this :
http://www.xjbikes.com/Forums/viewtopic ... html#67235

 

Thanks, Rick. Some very good advice and a very accurate summary of my concerns. I'm curious as to how you actually know three of them are stuck. You must have been able to sense a limit as to how far you can go before backing off. I have to be honest and tell you I probably would have considered "stuck" to be a relative term and continued cranking until it came loose - one way or the other. I applaud your good sense.