A funny thing happened to me ....

[Prof. Robert]

Well, that funny thing wasn't so funny. On the way to work Monday morning, I almost lost a valve cover bolt (the little rubber seal is/was missing). I'm not sure exactly when the bolt loosened up, but I lost about a half quart of oil--mostly down the left side of my bike and my left boot. When I tried to tighten the bolt, it did catch (sort of), but it spun rather freely; however, that effort and a half quart of oil got me home without any further problems.

Today, I finally had time to pull the valve cover off. And surprise, surprise, the threads in the boss (?) are stripped. Whoever did this knew he did it because he also used gasket sealer on the bottom of the valve cover gasket. Now I ask you, is that anyway to treat a perfectly (well almost) good motorcycle?

Anyway, my real questions are what is the best/easiest way to fix this problem--heli-coil, timesert, or do I have other options? Also, (if heli-coil/timesert is the answer) how do I determine what size heli-coil or timesert to purchase? And, can I drill the stripped threads out with a hand drill, or should I pull the head and use my drill press?

As you've probably guessed, I've never attempted a job like this before, but I'd like to give it my "best shot." So, if anyone has been down this road before, I'd sure appreciate the benefit of your knowledge and experience.

Robert

 

[roostershooter]

Dude, if it were me, I would take it to a machine shop and let the pros do it. Being that it's a head bolt it would have to be perfectly straight for the head bolts to properly line up. It would seem to me that it wouldn't cost to much to have that done. Having said that, you can purchase heli cores that will allow you to use the original size bolts. Good Luck.

 

[queretaro]

I had a similar problem on my 94 Mercedes E320 the last time I changed spark plugs , 2 valve cover cap screws would not tighten with the valve cover in place; however they would seat if I removed the valve cover and turned them into the threaded boss in the aluminum head. Thus it seemed that the first few threads in the boss were stripped. I solved the problem with about $2 spent for longer cap screws. Try this: remove all 4 cap screws; remove the valve cover; screw one cap screw into the 'problem' boss, if it catches, great you have the same problem. So, then you measure the cap screw's length in mm (millimeters). Google cap screws and find an online vendor of fasteners. Order one cap screw the next size longer than the original measured cap screw, and add 2 close tolerance washers of the same diameter to your order since the new cap screw may be too long and bottom out on the blind hole in the boss without the additional washers. Please don't be too upset if the new cap screw does not look like the BMW part; that's just the way it is with a $2 fix. Reassemble, ride away; and don't think twice, it's alright.
regards,
Mark

 

[ksnyder]

I used a heli-coil on mine because that is all the local store had in stock. The size is 6mmx1mm. I would have used timesert if they were available locally. I have had several of the 6x1 bolts strip out the aluminum. I have always used a torque wrench on the bolts. I have three wrenches for the different size bolts. I used a tap and die to clean up both threads after installing the heli-coil. It is an easy job.

 

[queretaro]

Adding to my first reply; I found what I needed at BoltDepot.com.
regards,
Mark

 

[Prof. Robert]

Thanks

Thanks for sharing your experience and knowledge with me, fellows.

I'll probably go with the heli-coil repair because I read some disturbing reports on line about using timeserts. According to a Cadillac cite, they're not easy for the novice to use; nor do they hold up as well as advertised. And as for using a larger cap screw, I considered it, but I'm concerned about the threads stripping again.

Well, anyway thanks again.
Robert