valve cover bolt holes stripped... options?

Right side, front two outer valve cover bolt holes are stripped. I have no idea what to do because the valve cover bolts are so unique.. Right now I'm considering adding some sort of c-clamp to stop a valve cover leak. I have no experience as a machinist so any ideas are welcome.

Help!

 

While the bolts themselves are somewhat unique, the threads are a standard metric thread. A shop can put inserts in the stripped holes. If you want to do it yourself it's not terribly difficult, but you should buy extra inserts and practice putting them into a peace of scrap before fixing your head. I'm currently on a break at work, but can post more information on the process later.

 

What year/model bike are you working on?

 

82 550 maxim. I'll call shops tomorrow for a quote.

 

Looks right

 

Got a 1/4in drill bit? An adjustable wrench? All you need is a Helicoil kit. You drill out what is left of the threads in the (relatively) soft aluminum, tap some new threads for the insert, and place the insert into thenew hole. Done. I did all 8 of my outer bolts last year cuz 3 were leaking, so the others were only a matter of time. Only took 20 mins for the whole shebang. Kit cost $40 and can be found at most auto shops, though I keep finding them for cheaper at tool shops. They come with (I think) 12 inserts, so you can even have leftovers. Which is fortunate, since it's a very common size on our bikes. Had to Helicoil my chain tensioner. Works like a charm.

The thread size you need is M6 P1.0

 

Just remember to put some painters tape across the oil galleries. Wouldn't wanna get chunks of aluminum floating in places you don't want floaties.

 

The tricky bit (and the reason why I recommend practicing first) is drilling the hole dead straight. Because of the nature of how the valve cover bolts seat (the wide lower shoulder of the bolt seats flat on the cylinder head), the insert cannot be askew, or you risk cracking the head when the bolts are tightened.

It is a very easy DYI job, but practice drilling a straight hole with a handheld drill and putting an insert or two into some scrap aluminum, or hardwood.

 

Drilling the hole straight is the key. Also don't drill to far down. Drill slow also a lube would probably help. I just did 3 threads on my 550. Took like 20 mins. Got it all back together and leaks are gone. M6 x 1.0 metric is what I used with a 1/4 drill bit. Good luck.

 

helicoil is the way to go...

 

Okay. Just bought the helicoil M6 x 1 kit from amazon for ~$26. Took a bolt into auto zone and confirmed its a M6x1 so should be good there. With prime shipping it arrives Thursday.

Any tips for drilling straight? I know my way around a hand drill well enough, but I mean should I prop the bike so I can come at it straight down and use the bubble level on the drill? How freaked out should I be by "drill it straight." I'm gonna be pretty darn careful.

 

the drill is going to want to follow the hole that's already there, but another set of eyes always helps. The other set of eyes can run a vacuum too.
tapping always goes better with a tap wrench too. If you use something with one handle it's harder to keep the tap straight. WD-40 for tap lube, two turns in, then out, clean the tap and back in.
you'll be fine.

 

If you have a variable speed drill just go slow. If you have a single speed drill you will need to be a little careful at the beginning of each hole. In either case drilling the hole out in stages will get you a straight hole with less chance of getting crossways. Don't worry if you don't have a bit that falls between the size of the current hole, and the final hole for the insert. It's perfectly fine to drill in a single stage.

 

I have been having this exact issue
ordered a kit
will the bolts I have work in the newly tapped holes then?
I can't imagine finding another bolt to fasten the valve cover with

 

Yes, that's the point. The bolts are an M6 P1.0 thread. So are the holes in the head. The threads in the head are pooched cuz they are aluminum. The bolts are steel (I think, someone correct me if I'm wrong), and they outlast the aluminum threads in the head. All you are doing is removing the old threads in the head, and placing a new set of steel threads that are M6 P1.0 in the head.

 

awesome!
so sick of weeping issues with my bike
I had a bent valve cover and I have torn up the holes
can't wait to have my bike back on the road

 

The weeping could also be an old rubber gasket and donuts. Food for thought. (Pun intended)

 

nope and nope
bent valve cover messed everything up
I have broken 3 camshaft mounts
and the last one that broke I can't find all the broken parts
I got most of the aluminum chunks
but one small one remains
I am hoping it is in the oil filter
but the bolt is stripped
so I am going to be cutting it in the next few days
what a nightmare

 

The threads are pooched because someone over torqued the fasteners. Threads don't just go away by themselves. Either exceeding torque specifications, corrosion, or using a fastener that has a high galvanic index when next to the other metal is what causes thread damage. One really good method for dealing with the first one is to have a service manual and a torque wrench. The second issue is dealt with by using a thread locking compound, or anti-seize(depending on the application). The third requires a bit of thought and research. For example stainless steel and aluminum have a high galvanic index when in contact with one another, and will eventually become corroded into a single, nearly irremovable piece.

 

I will admit to over torquing
mostly due to the bent valve cover
will helicoil
still searching for small shard of aluminum
hope to find it tomorrow
do not I have a new valve cover and Len is shipping replacement mount
will tackle Friday

 

I guarantee you are not the first owner of that bike to over tighten fasteners. I have put far too many helicoils in far too many machines to believe that it was just you, or just the warped valve cover.

 

and I do know the PO actually did do some maintenance
so I am sure I was not the 1st to mess with it
smart thing is I am actually fixing it properly

 

Alright guys, checking in. Helicoil went according to plan, thanks for all the insight. I was nervous but I think everything turned out okay. So thanks again.

Bolted the valve cover back in place (7.2 ft/lbs) and those two gasket semicircles on the right side weep oil! What do I even do about that? Gasket, donuts, everything is brand new. Can I thicken it up with a little rtv?

 

Eh, just JB Weld the thing shut! Done deal!

KIDDING!

Did you RTV the top (valve cover) side of the rubber gasket? Is the gasket new? Are the donuts new?
Check out Fitz's how-to on doing a valve adjustments. Follow his final steps for the part about putting the cover back on and you shouldn't have any leaks at all. I did, and I don't.

EDIT: Oops, I see now that you said the gaskets are new.

 

Maybe I got lucky? I just did the same thing your doing and I used zero rtv. I put just a bit of silicon grease on both sides. No leaks at all. Imo rtv just makes a mess. Although I've used every other time I've done the valves.

 

Pull the cover, clean the semi-circle in the head, clean the semi-circle portion of the gasket, smear a thin layer of oil resistant RTV or Loctite 515 on the gasket. Problem solved.

 

I really don't get the design of the 2 half moons
why can't that just be a flat area?
I am sure the engineers had a plan
but I can't figure this one out

 

Those half-circle cutouts in the cylinder head (that the half-circles on the gasket seal into) are on the right side of the head, one for each camshaft. It’s where the boring machine came into the side of the head to mill the cam bearing journals, and since those journals are lower in the head than the side walls of the head, they had to drill away a small portion of the head sidewall to allow the boring bar to machine the journals. Those half-circles now have to be sealed up…………………

 

makes sense
just wish there was an insert and a flat gasket
I know it is wishful thinking thou

 

Veeery interesting.. Touché Yamaha, touché.

Checking in, permatex ultra black stopped the leak for the most part. Buttoning down the hatch I must have cross threaded one of the other bolts on the left side like a complete roob asshat, because it just keeps spinning. Will be helicoiling that one as well, when the cover comes off next time, because for now, it doesn't leak.

Thanks for all the help everybody.

 

There is..... But you have to have the non-YICS head for that---- lol

 

There is, it's called a non-YICS engine!

 

Beat ya to it..... Lol

 

Dave, you are the Quick-Draw McGraw!

 

Heehee....

 

8 Helicoils later
one broken bolt.. it snapped at the nub (I was only using finger strength) will drill out in the winter
a new valve cover, new gasket
3 Camshaft mounting brackets
and a lot of time and frustration
I am happy to say that my leaking is over
it weeped so little I could care less.. I think it will settle and be all good
I am happy to say I win!
I was about to call it quits last week

 

Glad you're set

 

Hey guys, I've over torqued a few of the bolts in my head as well, and broke a cam mounting bracket. Where can I find one of those?

 

Do you mean one of the cam caps?

 

Stubs,

Pics would help when asking questions sometimes.....

 

Ok so here's what I'm talking about: Is this a cam cap?

 

That is not a cam cap. It's just there so the valve cover has something to bolt to in that area. You should be able to find a replacement on Ebay, or put up a wanted ad; someone here probably has one to sell.

 

OK, I can't find this little bracket individually but it looks like I can buy a whole cylinder head assembly for pretty cheap. Gotta love old jap motorcycles. Thanks for the help.

 

I'll look around......might have one

 

I'd really appreciate it if you did Hogfiddles

 

do you have the rest of it?

 

DOH!
Yeah you are going to want to make sure you have all the bits and pieces.

 

Oh I surely have little aluminum bits floating around in my engine now. Biggest piece I found was the size of a pea.

 

Drop the oil pan and flush the engine.

 

That's a good idea, thanks for the advice. Oh boy, here I go fixin my mistakes again haha