Author Topic: %$#^$% cam chain bolt! (with weird update) (Read 5101 times)

jeepster · « **on:** May 27, 2009, 12:04:45 pm »

OK so, here I am trying to get the cylinder head cover off so I can bring it in and get this shoddy helicoil fixed at a shop (I don't have the kit and have no idea how to remove the "bad" helicoil...), and the #&$%#$ cam chain bolt will not budge. Clymer says to just "remove it"...yeah right, thanks Clymer. After reading a few pages in the cam installation section they are saying that the bolt is set in place with LOCTITE...?? How am I supposed to remove this thing? Do I have to grab the sprocket with vice grips? An impact driver? I've got some liquid wrench on there now, but it hasn't seemed to help. WTF?

What else can I do here? How hard is it to remove a messed up helicoil and replace it? Can I do it with the cam in place? This is the bolt that is right next to the end of the cam... I was kind of thinking of just using loctite or something on the top of the bolt to kind of glue it on there... the bolt does kind of catch, it just can't be torqued down very much at all.

MCRider · « **Reply #1 on:** May 27, 2009, 12:09:38 pm »

Quote from: jeepster on May 27, 2009, 12:04:45 pm

OK so, here I am trying to get the cylinder head cover off so I can bring it in and get this shoddy helicoil fixed at a shop (I don't have the kit and have no idea how to remove the "bad" helicoil...), and the #&$%#$ cam chain bolt will not budge. Clymer says to just "remove it"...yeah right, thanks Clymer. After reading a few pages in the cam installation section they are saying that the bolt is set in place with LOCTITE...?? How am I supposed to remove this thing? Do I have to grab the sprocket with vice grips? An impact driver? I've got some liquid wrench on there now, but it hasn't seemed to help. WTF?

What else can I do here? How hard is it to remove a messed up helicoil and replace it? Can I do it with the cam in place? This is the bolt that is right next to the end of the cam... I was kind of thinking of just using loctite or something on the top of the bolt to kind of glue it on there... the bolt does kind of catch, it just can't be torqued down very much at all.

Uh... what bike?

kghost · « **Reply #2 on:** May 27, 2009, 12:09:55 pm »

I dunno what bike you have...

But I know a bit about helicoils....

If you can grab a part of the damaged helicoil with pliers, tweezers, or a hemostat...sometimes you can pull them out ...like unwinding a spring.

MCRider · « **Reply #3 on:** May 27, 2009, 12:12:23 pm »

yes you would want to wind it, not just pull it out. Winding will pull the steel wire that is the coil, out of the threads it is seated in, leaving as much of the head behind as possible.

jeepster · « **Reply #4 on:** May 27, 2009, 12:16:23 pm »

1982 Cb650 Nighthawk.

Quote from: MCRider on May 27, 2009, 12:09:38 pm

Quote from: jeepster on May 27, 2009, 12:04:45 pm

OK so, here I am trying to get the cylinder head cover off so I can bring it in and get this shoddy helicoil fixed at a shop (I don't have the kit and have no idea how to remove the "bad" helicoil...), and the #&$%#$ cam chain bolt will not budge. Clymer says to just "remove it"...yeah right, thanks Clymer. After reading a few pages in the cam installation section they are saying that the bolt is set in place with LOCTITE...?? How am I supposed to remove this thing? Do I have to grab the sprocket with vice grips? An impact driver? I've got some liquid wrench on there now, but it hasn't seemed to help. WTF?

What else can I do here? How hard is it to remove a messed up helicoil and replace it? Can I do it with the cam in place? This is the bolt that is right next to the end of the cam... I was kind of thinking of just using loctite or something on the top of the bolt to kind of glue it on there... the bolt does kind of catch, it just can't be torqued down very much at all.

Uh... what bike?

MCRider · « **Reply #5 on:** May 27, 2009, 12:25:42 pm »

Quote from: jeepster on May 27, 2009, 12:16:23 pm

1982 Cb650 Nighthawk.

[snip

That leaves me out. Someone will know.

jeepster · « **Reply #6 on:** May 27, 2009, 12:29:57 pm »

Hmmm. Somehow this doesn't sound like a very noob friendly procedure. The hole is tiny, needlenose pliers barely fit... What about getting the cam chain bolt off? Is this an even less noob friendly procedure? Godamn, so this is what working on bikes is like huh? Would you rather be burned or stabbed? $:-\$ I was kind of having fun up until this point actually.

Quote from: kghost on May 27, 2009, 12:09:55 pm

I dunno what bike you have...

But I know a bit about helicoils....

If you can grab a part of the damaged helicoil with pliers, tweezers, or a hemostat...sometimes you can pull them out ...like unwinding a spring.

turboguzzi · « **Reply #7 on:** May 27, 2009, 12:43:44 pm »

back to the cam bolt thing, you can heat the area of the bolt's thread with a propane torch, heat usually breaks the loctite's bond.

no need to get it red hot though ! ;-)

Inkscars · « **Reply #8 on:** May 27, 2009, 12:43:51 pm »

The way we get "bad" helicoils out is similar to kghosts proceedure, cept I don't know where yours is. Ours are almost always for plugs, fire engine for about 15 seconds, allows it to heat up and removes any debris from cylinder. then get needlenose or hemostat and pull it out. If the hole is too small, get a different tool. They're generally VERY easy to get out. After you've removed the old one, and before you insert the new, make SURE you use a magnet or something to remove shavings. It's a simple step that will almost 100% of the time guarantee a fixed right the first time repair.
Good luck.

jeepster · « **Reply #9 on:** May 27, 2009, 04:50:55 pm »

Woot! This thing would definitely be a 500lb sculpture in my apartment if it wasn't for the creative and inquisitive folks on this list. I had to step out to Danken (great little auto parts store on Morgan Avenue if you ever get stranded in Brooklyn) to pick up a little LED flashlight so I can see what's going on in that tiny little hole...

So, steeling myself for tricky job, I lit up that little hole and...NOTHING. There is no helicoil, NO THREADS, nothing in the hole (??!!) but a few tiny thread shavings. I can only think of two possible causes for this and both of them are uh, not good. My first (and highly preferable) theory is that the bastards at Cycle Therapy in Manhattan (I stripped this bolt on the side of the road on 149th st, so my options were fairly limited) never even put a helicoil in there in the first place, and just threw some liquid gasket or something down there and called it a day. My second (nightmare) theory is that the little helicoil somehow managed to shake loose down there and ended up pinballing around the camshaft,engine and creating all kinds of nasty metallic havoc.

Here's were the helicoil should have been:

And now for some PO/lazy mechanic weirdness:

Yeah, that's right the CUT bolt on the left has fewer threads and was used for the helicoil.

OK, so obviously I want to rule out the doomsday scenario here, so let me describe what happened when my bike died:

I sprayed carb cleaner directly down the fuel line to the carbs and ran the engine for a few minutes to flush it out.

I sprayed some carb cleaner into the airbox (Dumb, I know) and ran it for a minute or two with the airbox OFF on a dusty ass Brooklyn street.

I put my air filter back on, (dirty) and put the tank back on with a fairly dirty inline fuel filter in place. (are you noticing a trend here?)

Plugs were dry and sooty, which seems to fit right in with the dirty air filter, dirty fuel line, and probably dirty carb...did I mention my tank still has a crumbling kreme liner in it?

Noticed a slight film of oil surrounding the dreaded bolt, so I tightened it a bit. No torque wrench...queasy feeling as it just kept turning.

Started her up and it sounded weak and boggy, like it was running on 3 cylinders, then it began to buck and then it died. I noticed oil was practically spurting out of the bolt. Tried to start it again and it bucked a little, and barely ran with full choke. There was no grinding, or rattly noises so I am praying that the doomsday scenario never actually came to pass.

Some back story on the Cycle Therapy "fix": When I first tried to pick the bike up from their shop I started it up and it sounded super weak, oil was spurting out of the bolt. I gave it back to them and I picked it up a week later and the oil leak was (almost) gone. It has continued to leak very slightly since then.

Two months after the helicoil I laid her down at 30 or so, on the left side, helicoiled bolt is on the right. Sent her to a different mechanic for a tune up, and she ran pretty well after that for a few weeks, then I didn't have time to ride for 2 weeks or so, and she bogged down with throttle and seemed to be surging/missing (in heavy traffic on fifth avenue right by Rockefeller Center).

There is a THIRD (grassy knoll) theory that the more I look at the problem the more I think is what actually happened: The second mechanic for some unfathomable(malicious?) reason, decided to toss the helicoil. He was a big fan of liquid gasket, and there was a bunch of liquid gasket threads hanging off the cylinder head cover, cylinder cover joints and THE &%^#$ BOLT!!!!

Another reason I think this is what happened: there doesn't seem to be a whole lot of clearance above the cam for the helicoil to make it's way into the engine. Also, wouldn't I have heard some kind of metal on metal grinding noises if a helicoil had gotten ground up by the cam?

The only thing that is making me doubt this grassy knoll theory is that the cam does not spin so easily when I turn the bolt on the alternator to advance it. (still a noob here...) it spins freely for half a turn or so, then there is a little resistance...

OK, can anybody rule out the doomsday scenario entirely? Do I have to fish around for this helicoil? Speaking of, considering the hole has (theoretically) already been helicoiled, then the helicoil removed, do I have to JB weld the new helicoil on or something?

turboguzzi · « **Reply #10 on:** May 27, 2009, 11:18:01 pm »

uuh, staying up late i see,

calm down boy, a stripped thread will not be related to your bad running. for your doomsday scenario you should also see plenty of scoring marks on the cam, which doesnt seem to be the case.

let me check in my head which is dismounted now, if there's enough depth, you might be able to save your day by simply making a deeper thread + longer bolt.

the only problem with the very specific bolt is that ANY repair work will require blowing off with compressed air all the debris that will fall down the hole as this bolt ends up in the cam oil gallery. any debris there will shut off the oil supply to the cam. nasty.

BTW, you should hook up with cudjo, he's another noob form brooklyn

and dont get near to cycle therapy. dont ask me how I know.

TG

jeepster · « **Reply #11 on:** May 27, 2009, 11:49:33 pm »

Yeah, got a bit OCD stuck in my apartment with the bike today...perfect weather, and every 10 minutes I hear a CBR blasting down my block.

You're right of course, the cam is spotless, and there is no way a helicoil could squeeze through the tight space around the cam without damaging it in some way.

I think I'm going to try using a timesert (http://www.timesert.com/index.html) as it seems to be a more robust solution than a helicoil. My only concern is that the only timesert available for a 6mx1m bolt only has 9.75m of thread while the bolt has 15. Should still leave me with plenty of grip though. I was also thinking of threading the timesert in with some loctite for good luck. Hopefully, the opening is large enough that I can just tap in new threads and use the heavy duty timesert without drilling. Instead of compressed air maybe a shop vac to clear the hole? I am going to try and mask the rest of the cylinder head with duct tape and clear plastic to make sure no errant metal shavings escape into the camshaft.

I've got the Por 15 kit as well as a Davida carb sync tool on the way, so I think I am still on target for the middle of June.

martino1972 · « **Reply #12 on:** May 28, 2009, 12:22:37 am »

ummm,doesn't that bolt go all the way through the cylinderhead and threats into the cylinder bank..

? if it is you will have to remove the cylinderhead to fix the thread

Hush · « **Reply #13 on:** May 28, 2009, 12:41:34 am »

Settle Grettle, as my kids say

....your cam will have easy and firmer areas as the cam turns.
If Marti is right (and he does know 650's) then that longer bolt will be required.
This is always a problem when you take your bike (not your fault I realise) to some nob bike shop who have no idea how these dinosaurs work.

jeepster · « **Reply #14 on:** May 28, 2009, 12:43:00 am »

I don't think so... It's only 45mm long.

Quote from: martino1972 on May 28, 2009, 12:22:37 am

ummm,doesn't that bolt go all the way through the cylinderhead and threats into the cylinder bank..? if it is you will have to remove the cylinderhead to fix the thread

jeepster · « **Reply #15 on:** May 28, 2009, 12:48:26 am »

Sweet. I guess that pretty much eliminates the doomsday scenario.

Quote from: Hush on May 28, 2009, 12:41:34 am

Settle Grettle, as my kids say ....your cam will have easy and firmer areas as the cam turns.
If Marti is right (and he does know 650's) then that longer bolt will be required.
This is always a problem when you take your bike (not your fault I realise) to some nob bike shop who have no idea how these dinosaurs work.

martino1972 · « **Reply #16 on:** May 28, 2009, 12:48:27 am »

let me check my cylinderhead,got the engine apart right now.....

martino1972 · « **Reply #17 on:** May 28, 2009, 01:05:56 am »

your correct,it does not go all the way through........

here is what mine looks like....

looking at your picture there has been NO helicoil installed.......it's a simple fix though...but i would strongly advise to take the camshaft out,to prevent the risk of getting shavings under the cam journal while you are drilling out the hole in preparation for the helicoil....

martino1972 · « **Reply #18 on:** May 28, 2009, 01:08:36 am »

do you see that oiling hole under the cam journal..

you REALLY don't want shavings in there..!!!!!!!!!!!!

jeepster · « **Reply #19 on:** May 28, 2009, 01:45:46 am »

OK...#$%*. Virtually impossible to drill with that oiling hole so damn close. What about a non-drilling solution? how about the timesert set in JB weld? I just have a bad feeling about that cam chain bolt...seems like that sprocket bends pretty damn easily and the bolt is basically welded on there.

Won't heating the sprocket warp or otherwise potentially damage it? How do I keep it from turning?

martino1972 · « **Reply #20 on:** May 28, 2009, 02:06:35 am »

when i took my cam bolts out i just put the ring side of a good fitting wrench on the bolt and "tapped" on the end of the wrench with a hammer... i had a vice grip carefully holding the sprocket in place(watch out for pinching the cam chain with the vice grip though)... heat should work good as well,but i was too lazy to grab a torch...they came out pretty easy after the initial whack on the wrench....

there is no good solution to fix that thread without drilling,tapping and heli coil that hole....easy way to prevent shavings coming in that oiling hole is to tape it off with some duct tape....
also,you can put some heavy grease on the drill bit when drilling(well,just before you start) so that most of the shavings stick to the grease....

see,in order to heli coil that hole,what you do is buy a heli coil kit of the proper size,i think it's m6x1.25 but don't pin me on that though,CHECK..!! the kit comes with some coils,a tap and a insert tool....on the box it should tell ya what size drill bit you need...

then first you drill out the hole,it really doesn't get much bigger,try to keep the drill strait up as you drill thus preventing the hole to be under an angle....then run the tap from the kit in the hole,giving you the proper threat for the coil....then put a coil on the insert tool and screw it in the hole....remove tool and your done...

it's really simple to do,if you have everything handy it takes less then 2 minutes....

the tap and insert tool from the kit you can use over and over again and the coils you can buy separate,mostly there are around 5 coils in the kit itself,giving you 5 holes you can fix.....

London Dock · « **Reply #21 on:** May 28, 2009, 12:29:18 pm »

Hey Jeepster and all,

Guess what? Same thing happened to me YESTERDAY...same bolts and location! Had oil leaks around the top of the cylinder head cover (search for "CB650 Cover Leak"). Got new OEM washers...but could not even hand tighten the right side bolt, it just kept on spinning.

My 6mm Helicoil kit should be here tomorrow

. This seems like a common problem, but don't sweat it! Anything is fixable...nice to know about that oil galley though!

By the way, when you took the cylinder head cover off, did you slack all your tappet adjusters on the valves before removal? I know you HAVE to do this and use the rubber band method for installation to avoid bent valves, but what about on the removal stage?

jeepster · « **Reply #22 on:** May 28, 2009, 05:31:32 pm »

I counted about 5 or 6 italicized "severe engine damage may result" warnings in the Clymer's section on Cam and cylinder head removal. I think I am going to investigate masking off the cam and the rest of the head with duct tape before I attempt this.

Quote from: martino1972 on May 28, 2009, 02:06:35 am

when i took my cam bolts out i just put the ring side of a good fitting wrench on the bolt and "tapped" on the end of the wrench with a hammer... i had a vice grip carefully holding the sprocket in place(watch out for pinching the cam chain with the vice grip though)... heat should work good as well,but i was too lazy to grab a torch...they came out pretty easy after the initial whack on the wrench....

there is no good solution to fix that thread without drilling,tapping and heli coil that hole....easy way to prevent shavings coming in that oiling hole is to tape it off with some duct tape....
also,you can put some heavy grease on the drill bit when drilling(well,just before you start) so that most of the shavings stick to the grease....

see,in order to heli coil that hole,what you do is buy a heli coil kit of the proper size,i think it's m6x1.25 but don't pin me on that though,CHECK..!! the kit comes with some coils,a tap and a insert tool....on the box it should tell ya what size drill bit you need...

then first you drill out the hole,it really doesn't get much bigger,try to keep the drill strait up as you drill thus preventing the hole to be under an angle....then run the tap from the kit in the hole,giving you the proper threat for the coil....then put a coil on the insert tool and screw it in the hole....remove tool and your done...

it's really simple to do,if you have everything handy it takes less then 2 minutes....

the tap and insert tool from the kit you can use over and over again and the coils you can buy separate,mostly there are around 5 coils in the kit itself,giving you 5 holes you can fix.....

jeepster · « **Reply #23 on:** May 28, 2009, 05:37:50 pm »

I didn't...the cover came off very easily though so I am sure no valves got bent. Also, just to double check...the thread pitch is 1mm on that bolt right?

Quote from: crazyguy100 on May 28, 2009, 12:29:18 pm

Hey Jeepster and all,

Guess what? Same thing happened to me YESTERDAY...same bolts and location! Had oil leaks around the top of the cylinder head cover (search for "CB650 Cover Leak"). Got new OEM washers...but could not even hand tighten the right side bolt, it just kept on spinning.

My 6mm Helicoil kit should be here tomorrow . This seems like a common problem, but don't sweat it! Anything is fixable...nice to know about that oil galley though!

By the way, when you took the cylinder head cover off, did you slack all your tappet adjusters on the valves before removal? I know you HAVE to do this and use the rubber band method for installation to avoid bent valves, but what about on the removal stage?

London Dock · « **Reply #24 on:** May 28, 2009, 05:56:37 pm »

Yes, I checked the bolt that came out of my machine on a standard M6 nut. Fits perfectly. If you Google or Wikipedia ISO metric threads, the M6 has a regular 1 mm pitch. Good luck to us both!

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Author Topic: %$#^$% cam chain bolt! (with weird update) (Read 5101 times)