Exhaust Flange Stud Removal and Thread Sizes

I am in the midst of replacing the exhaust flange studs. I have two broken at the end of the threads on the nut side. Other than WTF I should do about extracting the broken studs, I need to know the thread sizes on each end of the stud. I am going to have to run a tap through the head when I get them all out. I think the nut side is M6X1 but what is the head side? Any input will help!

As for the stud extraction.. i've used pliers, screw extractors, two-nut method (not applicable to the remaining studs), heat + pliers. What i haven't tried is taking the bike to a shop or i've also seen "external extractors" I call them than but they're basically sockets with reverse cut threads but i have yet to see one small enough for these studs. The last thing i want to do is remove the engine from the bike to make anything happen.

Thanks again for any input.

Kyle

 

My 650 came with one broken. I made a new one by cutting a bolt - so they must be same thread whole length.

In my case there was room to grab with pliers. I heated the boss with a oxyacetylene torch with a #3 tip set to the smallest flame it would maintain. The stud wasn't even finger tight. Keep the torch moving so you don't burn a piece off the boss.

 

I would try to use some Kroil on it and let it soak in and see what happens.

 

oh and I also used liquid wrench.. I've applied it three times over the last three days. It helped remove the last full stud but no luck with the broken ones. I'll try more heat tonight but i'm not getting my hopes up.

 

Kroil works when Liquid Wrench won't honest.

 

Unfortunately it's not available in canada. I will try to order some for the next time I need a good penetrant but I just took the bike in to a local shop today, I have a credit with them anyway. I'll find out how they finished the job and let you know. I would also seriously consider buying these (or similar) for next time I'm faced with this problem.

http://www.everyspaceheater.com/Facom%A ... O1142.html

 

You are in a BAD Situation.
The first rule of Motorcycle Repair and Maintenance applied to the situation you have, there, right now.

"Don't do anything that will make a Bad Situation, ... worse!"

The Intake Cap Screws and Exhaust Studs are very-low quality SOFT Steel.
Once they SEIZE in place they will twist and break-off rather than come free.
Attempting to extract them, even after treated with penetrating products, is still a gamble.

Servicing the EXHAUST Side has built-in difficulty due to having very limited space to operate.
The Frame gets in the way, too.

Before you begin any adventure removing the broken studs from the Head; consider how the situation may deteriorate.

You might be BETTER OFF removing the Head and having ALL the Studs and Intake Cap Screws removed by a Machine Shop equipped to Drill-out the seized parts and return the Head to you with all the threaded holes in perfect condition.

 

Hey Kyle
Try these guys. I did a one time bulk purchase for us in Central ontario a while back. Call and ask for Doug to see what he can do. Even if you've already moved past the "Kroil" stage, at least you'll have some for the next time.

Good luck, Graham
http://www.westernbearing.com/

 

I appreciate the input. I would mostly agree with taking it straight to a machine shop. However, those with enough experience to try to gently remove them before resorting to the more time consuming/costly option is a perfectly reasonable option as well. This is the route that I've gone. When it came to the point where I realized I would put myself in a really bad place if I pushed any farther I handed the bike over to the pros. I'll let you know how that turns out and I may be eating my words by then haha

 

I hope they loosen-up and get extracted without a lot of fuss.
That's what you hope for.

But, this is one of the downsides to caring for these bikes.