| Author | Message | ||
     Newbuellertoo |
Despite reading all of the posts warning of it, and taking extra care and caution I managed to strip the bottom Derby Cover threads. Man do I ever feel stupid!!!! The threads have actually separated from the Primary cover. I have never used a Helicoil before and don't even know how they are sized and used. Is it possible to just re-tap the hole, or is it too late for that? I really need to get my bike back on the road by Wednesday. Any advice, pictures,procedures would be greatly appreciated. Will the three remaining screws hold the cover on tight enough to prevent leakage past the gasket if I end up having to take the bike for repair as a last resort? | ||
| Reepicheep |
Heli coils are at most local hardware stores, and are probably cheap in the size you need (smaller SAE). Go slow and careful, and follow directions, and it should be a very easy job. There is not enough material left to retap for the same size. You can go up one size, but that creates other headaches. Go slow with the heli-coil tap, reverse often, remove every few complete turns to blow out chips with compressed air or WD-40. Keep it lubed. If it jams when trying to back it out, work it back and forth until it clears, don't just try and force it backwards. Measure the depth you want to cut ahead of time and mark it on the heli-coil tap so you don't cut too deep. Except I think those holes go all the way through, so thats one less thing you have to worry about. Stuff a rag in there to try and catch chips and shavings coming out the back. In the future, pay attention and make sure you don't pull the heli-coil out with the bolt. If you do, no big deal, just make sure that bolt (and heli-coil) go back in the hole they came out of. All in all, its pretty easy. You can probably get away fine without drilling as well if you don't have the right size drill bit. | ||
| Newbuellertoo |
Thanks Reep, I got the helicoils, tap & tool at an Auto supply place and bought the correct drill bit. I will follow your advice and take it slow and easy. I have a magnet on a flexible wand that I will use as well to make sure filings stay out of the case. Wish me luck! Thanks Again. | ||
| Jlnance |
 I just did this last week. The magnet isn't going to help, you're drilling aluminum. But that's also good news as it is soft. It isn't terribly hard to use Helicoils, though if you have a block of aluminum laying around you might do a practice hole on that so your first attempt won't be into your primary cover. But this isn't a hard job. Stuff some rags into the opening behind the inspection cover to keep the filings out of your primary. | ||
| Reepicheep |
A "glob o grease" on the drill is also helpful to keep shavings contained. I have also used a second person (or duct tape) with a shop vac inlet running right next to the drilled hole as I am cutting and tapping as well. Probably overkill, but it makes me feel better. | ||
| Reepicheep |
Oh, and the one way a heli coil could get confusing in this context is if it is "too long" for the hole. If this is the case, you are better off "shortening" it before you install it, rather then trying to do so after you install it. Though all is not lost if you get it in and it is sticking out... its just more of a headache. My tool drawer is getting a nice little collection of those thread repair kits  | ||
| Jlnance |
Oh, and the one way a heli coil could get confusing in this context is if it is "too long" for the hole. It isn't in this case. It's actually a short enough screw that you don't have to break the tab off the back of the coil. I'm assuming newbuellertoo as already attempted his first coiling. Hopefully it went well. It just occurred to me that I should have mentioned to avoid drilling out the back of the primary cover. Hopefully he didn't need that advice. So how did it go? | ||
| Newbuellertoo |
Thanks Jim, It went fine. I kind of eyeballed the depth as I was drilling and only went as far as I thought I needed to to get adequate threading from the tap. Everything seems to be okay, the helicoil went in fine and the screw was able to hold the torque. I actually used the shop vac with the mini "Crack Cleaner" nozzle while drilling and tapping and it kept the area "debris free" Thanks for the advice. Please be on stand-by for the next "This should be easy" maintenance item I try.  | ||
| Jlnance |
Newbuellertoo - Glad it went well. I remember the first time I broke off a bolt, I thought I had to buy a new bike. I've learned a lot. Keep the helicoils handy, this won't be the last time you use them. For anyone reading this tread who finds themselves in a similar situation. You can mark the drill bit depth by putting a piece of tape on the bit. Guage the depth from the distance the screw sticks out the back of the cover. These holes don't go all the way through the primary, and you don't want to create one that does. | ||
| Reepicheep |
I started my journey with the exact same repair you just did. I just rebuilt the top end of my KLR-250. Errrr... twice. Three times if you count the time I had to go back in to synchronize the counterbalancers, that I got out of line when I was hunting the rocker arm nut that got ingested. So at least with me, the stupidity factor is constant, the projects just get bigger | ||
| Newbuellertoo |
I bought this bike used and loved it but didn't feel a real connection to it. The more work I do on it, the more it feels like "MY" bike. I'm sure I will have plenty of opportunities to it more 'Mine". Thanks again for all of the help guys. p.s. The service manual is getting more abuse than the bike!!!  |
