Well a long time ago I over tightened my valve cover bolts and my engine head has been discoloring/getting brown ever since. I came to the conclusion that this was b/c oil was leaking ever so slightly from the bolts that I overtorqued.
The oil basically would melt and discolor/brown the enamal or whatever finish is on the engine. So I decided to rebore the threads. The orinal bolts are 6mm and I want to go one size up (7mm) BUT i can find 7mm anywhere. Anybody know where I might be able to find a 7mm bolt?
You'd have better luck using a keensert or helicoil and using 6mm hardware.
Keenserts are better than helicoils because they don't back out the next time you remove the fastener
My local Ace hardware has 7mm fasteners.....but DP is correct. Get some flavor of thread insert. The fasteners will work as designed and the female threads will be stronger than OE.
Quote from: uclabiker06 on June 11, 2011, 06:25:22 PM
Well a long time ago I over tightened my valve cover bolts and my engine head has been discoloring/getting brown ever since. I came to the conclusion that this was b/c oil was leaking ever so slightly from the bolts that I overtorqued.
The oil basically would melt and discolor/brown the enamal or whatever finish is on the engine. So I decided to rebore the threads. The orinal bolts are 6mm and I want to go one size up (7mm) BUT i can find 7mm anywhere. Anybody know where I might be able to find a 7mm bolt?
Reboring and tapping new threads or installing Timeserts is a fairly major job. Are you sure the threads are actually stripped? Do the bolts continue to turn with light force from an Allen wrench? Can you post a picture of the leakage?
Unless the threads are clearly stripped, before undertaking a thread repair I think I'd take the covers off again and apply a very light coat of Threebond (same as Yamabond, Hondabond, etc., sold at all bike shops) on the gasket surfaces and try again. The bolts are in blind holes and I don't think oil can be working its way up along the bolt threads, the only way for it to leak or seep is past the gaskets. Those bolts do not need to be very tight, and I'd apply some Loctite 242 which may help with slightly damaged threads. I don't know what the manual recommends for torque on those things but it's probably below the range where a standard torque wrench can accurately measure. I would just tighten them "snug" by hand feel. The Loctite will keep them from coming loose if you err on the side of not tight enough.
Loctite also makes a Form-A-Thread repair kit that "may" be suitable but I've never used it. Maybe someone else has some experience with it.
My point is that I think the repair needs to be balanced against the severity of the problem. Timeserts are the best solution if the threads are actually stripped, but this approach is going to take some money and time, probably including removal of your heads to do properly.
Bob
Well, the leak is not visible by eye, but I know its there b/c the finish for the horizontal head keeps getting more brown and the finish looks "cracked" in one area. As time has gone by its gotten worst. I think the leak is VERY small. Its definitely not a drip and you wouldn't get any oil if your rub your finger across the area but it must be there.
Anyways I looked at some other guys monster with much more mileage than mine and his horizontal head wasn't brown so there is a leak but the threads are not completly stripped and they do tighten up to the correct torque, which is 5ft/lbs I beleive. Actually I think its only one of the bolts that I really got at but it was so long ago that I don't remember which one it was so I have to take care of all of them. Maybe I'll just get one of those green foam like gaskets that ca cycleworks sells (maybe they will work better than oem?). Anyways if I take the valve cover off I will have to replace the gasket so I guess I might as well get a new one. Man I just don't know what else it could be? and my bike is way out of warranty. http://www.ca-cycleworks.com/ca-cycleworks-fiber-valve-cover-gaskets-4-gaskets (http://www.ca-cycleworks.com/ca-cycleworks-fiber-valve-cover-gaskets-4-gaskets) Can I apply threebond to this type of gasket?
I tried degreasing and even using a toothbrush but that stuff won't turn back to the right color. I just don't want it getting any more disscolored than it is already. I planed on doing it with the head on and just taking my time; time will not be a problem. Do you guys think the walls are thick enough to allow for an insert?
Langonobob, I think this form-A-thread repair kit with some threebond on the gasket might be just what the doctor ordered. Takes temperatures up to 300F.
http://www.midwayusa.com/viewproduct/?productnumber=986916 (http://www.midwayusa.com/viewproduct/?productnumber=986916)
Is it possible to switch the vertical head with the horizontal one? the finish on the vertical is perfecto.
I think Speeddog's shop is just over the hill from you? My recommendation is before attempting any kind of repair or taking anything apart, ride it over to Valley Ducati Service and let them take a look at it. You seem to be convinced that your paint is discolored because oil is leaking due to overtorqued bolts but this is far from 100 percent clear over the internet. A second pair of eyes never hurts and having a professional diagnose the problem first hand could save you a lot of time and money in the long run.
Bob
I hear you. I think I just need to make sure there is not oil in the bolts or the female ( I didn't do that before ) and some loctite. I don't think they got stripped.