Broken Cam Bolt

No need to use loctite on cam cap bolt's, the bolts are under constant tension from the valve springs pushing up on the cam shafts and the caps. If you must use loctite use small screw loctite 222 (light blue)as it meant to be removable...

1045

Here is the easiest and best way to remove the broken bolt. This works especially well on removing bolts from aluminum parts as the expansion/contraction differences between steel and aluminum help to free the bolt.

I just used this method lask week to remove 2 broken bolts from a set of kz cases.

If the bolt sticks up above the surface a little, find a nut that will slip over the top of the broken bolt. Lightly weld the nut to the stud from the inside of the nut. A quick spot weld is all that is usually needed. Put a wrench on it and twist it out.

If the bolt is broken off flush with the surface...I find a washer with an i.d. that is just a little smaller than the o.d. of the broken bolt. I lay it over top of the broken bolt and tack weld it through the center. Next, I tack weld a nut to the washer. Put a wrench on it and twist it out.

The small amount of heat that transfers through helps to break the bond. I keep a wet rag handy and immediatly cool the tack welds so as not to allow too much heat build up.

If the part is off of the bike, you can put it in an oven at 300 degrees for about 10 minutes. The heat will cause the aluminum to expand quicker than the steel and make removal easier.

Post edited by: Zeuss, at: 2005/10/29 20:52

Use a bit the same size as the hole to drill a countersink. This is much easier than center punching wich is nearly impossible if its deep in the hole. Then just use a small bit to drill into the broken bolt and use the easy out to extract.

Post edited by: nads.com, at: 2005/10/30 00:45

bluegill wrote:

I had the same experience, as have several others. I got it out with an easy out, basically a reverse threaded bit. Here's my post from then...
kzrider.com/forum/viewthread.php?tid=21457

As for getting a new bolt...

Jeff Saunders graciously told me about fastenal.com when I asked him about replacing those bolts on my 750E1. I also broke one off but was able to get it out with an easy out. Fastenal had all 16 bolts for about a dime each.

If people are twisting these things off at torque spec., what is the strength rating of these little bolts? I'd like to get a higher strength grade and have one less thing to worry about.... When I put mine back in last winter I didn't have a problem, but I was papranoid because of the other stories. I backed my torque setting down a bit off the lower end of the recomemned scale. I'd still back the torque down a tad, but would like stronger bolts.

As a word of warning...I had my cam cap bolts torqued to 10 ft/lbs, which is slightly MORE then spec...and still, about half of them had come loose when I opened up my valve cover today.

I also had a cam cap bolt break off and I was lucky enough to have someone helping me that knew how to fix it. The first thing he did was put masking tape all around the area (and over the bolt too). Then, cut a little of the tape to expose enough of the bolt to see where to drill. No metal got inside the engine because of the tape. A regular easy out worked just fine for me. I think the key is to get the hole drilled right in the center of the bolt (easier said than done, I know). I also found out that the one bolt that broke was not a hardened (grade bolt, and I'm sure that's why it broke. I have never used locktight either, and have never had a problem. The cams are out once per year to adjust the valves (shim under bucket). Good Luck, I hope it comes out OK.

I wonder if some of you have bad torque wrenches, or are pulling them at the wrong angle ect. It still seems unlikely a bolt could possibly break off here, and if you got 10ft/lb without stripping the aluminum, you were very lucky. No need to overtighten these. Just my experience in 300,000 miles of KZs, cam bolts broken=0, cam bolts that came loose between valve shim service=0, stripped threads in the aluminum even at about a 6 ft/lb torque setting= maybe 6. Be careful.Always the exhaust side will strip, don't know if the thread design is a little shorter on that side, or the aluminum gets soft from heat?

'Home Depot' sells 'Easy-Outs' as a set with the drill bits. They're like $7.00 and the T-handle for them is like $5.00. The drill bits that come with them are phenominal too. They'll cut through anything very smoothly, and you get shavings, not metal dust, which is much easier to keep up with, and they also generate less heat inside the bolt when you're drilling which makes for easier removal. They come in sets of three different sizes and I've used them on everything from suspension bolts, to set-screws.

I can get stuff out that I used to have to pay a machine shop 40 bucks for. And do it in 5 minutes too!

RonKZ650 wrote:

I wonder if some of you have bad torque wrenches, or are pulling them at the wrong angle ect. It still seems unlikely a bolt could possibly break off here, and if you got 10ft/lb without stripping the aluminum, you were very lucky. No need to overtighten these. Just my experience in 300,000 miles of KZs, cam bolts broken=0, cam bolts that came loose between valve shim service=0, stripped threads in the aluminum even at about a 6 ft/lb torque setting= maybe 6. Be careful.Always the exhaust side will strip, don't know if the thread design is a little shorter on that side, or the aluminum gets soft from heat?

OK, maybe I was getting paraniod about nothing. I didn't have any probs with my bolts, and like I said, I backed them off a lttle during torque down last winter. I just try to keep a heads up on any potential problems.

Well do update everyone, I did get the bolt out. I took the advice of going to Home Depot and buy the number 2 screw remover, and a 3/32 bit. I had one broken bolt on my handle bars, and of course the one on the cam bolt. I was amazed at how well it worked on the handle bar bolt. That bolt was even rusted tight. I then tried it on the cam bolt. It did losen it, but then it broke. It was lose enough for me to coax it out with a pair of needle nose. Now if anyone has a suggestion for some cheap shims, I am all ears.

Good to hear you got those bolts out.

A tip:
When you bolt your cams back on?
some of the lobes will be pushing on valves, so tighten ALL the cambolts evenly and slowly, like one turn per bolt at a time, work from side to side. This will put equal pressure on the cam as you draw them down.
Also ? The cam bolt sholder (the upper part of the bolt that is threadless?) make sure it's clean and rub a dab of white grease on each one prior to inserting it in the cam-cap. Take your time, torque to spec's.

P.S.
Between my Kawasaki dealer and a local small motorcycle shop, I was able to get my shims either by steight swapping or a few dollars, I also bought one 200 shim from Jeff at Z1 enterprises.

Post edited by: ~DW~, at: 2005/11/03 11:32

many times when the head snaps off a bolt when you are installing it the tension is released in the bolt and you can just back it out with a small punch or chisel,if you have to drill it out aleft handed bit ,or e-z out should do but make sure to protect motor from shavings.anytime you mix two differant materials put a little anti seize on the threads it will lube the threads and give you a truer torque reading ,also prevents electrolosis between the two materials.hop this helps happy wrenching!