Exhaust leak 85 xj700

I have an exhaust leak on one pipe. Looks like the bolt or stud ( which is it?) is gone. Not a bad leak just pops a little. Can this be replaced if so what size is the stud? The leak is where the pipe attaches to the cylinder

Thanks

 

yes it can be replaced is it broken off or just missing? its a stud if you are talking about cylinder head to exhaust flange.
you may be able to figure out thread size if you look up the torque specs in your manual if you have one.

 

Yes that's the one. Couldn't find a picture in my manual. Could it just be listed in the torque specs? I see threads if its broke off its down in the cylinder head. Haven't taken it off yet. Thanks for the info

 

yes it will list it in torque specs as some sort of nut
cylinder head exhaust pipe stud bolt M6 x 1.0 7.2 ftlbs apply oil
thats what it says for my xj550 yours may be different size it will not give you the length
if you look it up on a parts site www.yamahapatrsnation.com the part # will have the length in it as mm
sorry it does not show it in that part number

 

Ok I'll look at those specs. Will it hurt to run it with a leak?

 

it may run lean and hot on that cylinder eventualy could burn a valve.
local machine shop could fix it for you maybe one at the auto parts store.
they may ask you to remove the head.
I am sure someone will reply and tell you how to do it. if you can post a photo of it by using upload file
is any of the stud left exposed? if so start treating the stud with your favriote penetrating oil, pb blaster ect.
its possible it just fell out if you are lucky.

 

Which header is it (#1 is to the left as you sit on your bike)? Is the stud missing or broken? Let us know. If you ride it without both studs vibration will eventually snap the other stud.

Gary H.

 

It is the #1 header and the stud appears to be gone. Here are some pics



Didn't know what size pic to post. If this isn't right let me know

RPS

 

just fine on the photo good detail . you still have some stud sticking out of the head.
almost all the way through the head after pipe is removed that is good, and it is the number 1 cylinder. easy to reach.
the rest just depends on your skill set and tools.
you should be able to remove that #1 exhaust pipe by undoing the clamp at the collector and removing that last nut. pb blaster the involved nuts and bolts for a day or two to let it soak in good.
get the pipe off, you should be able to get that removed with out removing head.
I would get the pipe off then put it back on go to a bike shop or machine shop auto shop and ask how much to fix it on the bike explain the pipe is now loose or will be off when you wheel it in. the mechanics biggest concern will be with breaking your exhaust so if you have it off it will be an easy job.
it looks like you could do it your self if you have the tools, but if you snap it off flush to the head it gets harder.
do you have a torch to heat it up with?
treat stud with peneterating oil for a few days tap it with a hammer a few times loosens the rust, heat up at head and base of stud. grab it with real vise grips and see if it moves. just rember the harder you wrench on it the more chance of snapping it off clean.

 

Have to work today. I'll start soaking it for a couple of days and see what happens. Will one of those propane torches get hot enough to help loosen it? Id like to try and do it myself the local shop is run by young guys who have never seen a carburetor!

 

Yes and too hot if you're not careful (the head is aluminum). Follow what 550 advised and the stud should come out easy. Key note: chase down the threads with the new stud to remove debris before final installment.

Gary H.

 

Great! I'll give it a go. I'll see if Len has that stud

 

more heat to stud then head , good luck

 

Thanks I'll let you know how it goes!

 

What's left of that stud looks to be recessed into the head. That calls for a nut to be welded on so the remainder can be backed out.

 

Looks to me like it's barely sticking out the hole. I was thinking 550 is seeing it different to what I see.

Gary H.

 

Got the other nut off. Not sure what's going on inside the other hole! Don't see any threads

 

Looks like PO tried to remove it and failed.

 

Umm, maybe. How far do the threads go? Is what I'm seeing at back of hole the stud or the bottom of hole?

 

What you are seeing is the remains of the stud and a mangled hole. You do not have a DYI repair in this case. A Machine shop, a very experienced motorcycle shop, or a replacement head are your options. When you figure in the cost of gaskets, a replacement head is likely to be the most expensive of the three.

 

Does the head need to be removed to be fixed? Or can it be done on the bike?

 

You'll have to ask whoever will be doing the work. There are a host of methods.

 

Would it be possible to put an insert like a hellicoil in there? How thick is the wall of the cylinder head?

 

it can be helicoiled heilcoil is used if the threads in the hole are damaged beyond repair but you still have to remove the stud. you should get a price on he job before thinking of doing it yourself, if you screw it up it will cost even more.​

 

New pics look like PO (or whomever did it) tried to drill out the stud, mangled the hole, nicked the head with the tip of the bit a couple times then decided f@!k it and used something like jb weld. I agree with k-moe, it's not a diy job. The hole will have to be reamed clean, the stud removed, the hole plug welded, drilled and tapped, insert installed then new stud installed. I also agree a decent shop can fix it no problem.

Gary H.

 

Ok guys thanks for the advice! There is a shop here that rebuilds and repairs car engines and parts. I'll give him a call. I'll let you know it goes.

 

Update. BigT, kmoe, rocs, y'all were correct. PO tried to drill out stud then opted for jb weld!

Took it to machine shop, the hole was too big to helicoil without going to a larger size, filled hole and retapped for same size. Under a 100 bucks. Parts orders from Len

I'm happy!