Snapped a Manifold Intake Allen Headed Cap Screw... crap

Well during my first experience removing the carbs I made the mistake of thinking I needed to remove the boots to the manifold, and in the process snapped the first screw i tried to loosen. On a brighter note I got the carbs off with relatively little trouble after I made that mistake. So how screwed am?

 

Okay after testing the search function out, I see that I need to get to a machine shop. Do I need to take the head off? Also I know I'm going to need to prepare the wallet for this hit. How much would you guys guess I will be looking at?

 

depends on the machine shop, and whether you want to remove all of them while it's there. Just one should be maybe $20-35. But, if you have to have it off anyway, you should check the valves/guides, decarbon etc. How many miles on the bike?

 

I've done the same thing. I just drilled out the old screw and tapped new threads in there to install a new screw. I didn't try to remove any of the rest now and don't plan to any time soon. If the boots are cracked (like mine are) I just coated them with Goop and repainted them black. Worked for me!!

 

The bike has a new odometer on it installed by the PO, but I do have the original, and it reads 17k. And no I don't plan on removing any more of those terrible terrible bolts. $30 bucks isn't too bad for a lesson I don't guess And PainterD I think i will follow your idea with goop and paint. Good thinking, and thanks guys

 

Someone here who I can't recall now suggested using "liquid Tape" which is black and is used on electrical connections, dries fast, is pliable and gets into crevices beautifully. I found it at the True Value Hardware and is like $8 or so. I used it on mine and it filled all the tiny cracks beautifully

If the cracks in the rubber were so deep as to go through & allow an air leak, it might work but there's other methods of repairing that where the manifold was encircled by rubber and sealed. I don't recall the exact material but a search here will find it.

 

You need to remember that the Manifold with the Broken Bolt is now loose.
This sets you up for a Major Air leak.

One solution will be to apply a Sealant to where the Back Side of the Manifold meets the Cylinder Head.
"Tucking-in" the Sealant into the joint where the Manifold joins the Head.

 

As Rick-o-matice stated, you could have a leak there if not addressed properly. But I found my manifold intakes were stuck on so tight, I rode it for the remainder of the season without even fixing it, with no air leak at all. I just thought it looked better with a bolt in there when I painted the engine.

 

I used an old bicycle inner tube to cover mine up,coated them with goop first then slid the inner tube over it.It was a tight fit but no more worries about the manifolds.....

 

Does anyone know the length or these intake manifold bolts? I wanted to run out and buy some Kroil and some stainless bolts... haven't tried taking one out yet. I think they're M6, but what length?

 

I'll answer my own question. On my XJ550J Maxim 550 the intake manifold bolts are M6-20 (that is M6 bolts 20mm long). The length is 20 mm. I'm seeding this post with some keywords for searching. Remarkably they came out with no heating, Kroil, PB Blaster, or cursing.

 

If you have them all out, ...

Get rid of the OEM Cap Screws for Hardened or Stainless.
Run a Tap in the Holes and clean them up and out.

Wrap the New Fasteners with Teflon or AntiSeize Compound the Threads in the Head.

The enjoyment that one of these Bikes can bring goes flat when dealing with those fasteners and they break.
Yamama dropped the ball using those Cheapo Cap Screws without treating the Holes with something to prevent the seizure.