I've been doing my own oil servicing for over 25 years over countless bikes... I finally did it, I threaded a sump plug Long story short, a little while back I bought 4 new torque wrenches (mechanical) to cover ranges from 5Nm to 350Nm. The second torque wrench in there (5-45Nm) decided it would shit it's self and caused me to snap a steering head pinch bolt. I chalked it down to me being a muppet and figured the brand new torque wrench with a lovely QC chart wasn't the problem and continued. I recently did a normal oil service, using the same torque wrench and it has resulted in me over tightening a sump plug... I knowwwww, I knowww, I should have felt it before it started to thread, alas, the dreaded 'oh, that got looser' feeling came and I knew what had happened. Fast forward to today, I got a few sump plugs in the post as I was desperately hoping the problem would just magically go away with a new plug, clearly that wasn't the case. I have ordered a E-Z Lok (M12x1.75) kit to fix said thread. I've never attempted such a job before yet I hear it can be fairly straight forward. Unfortunately, I don't have the tools nor time to remove the entire engine to get the engine casing off and into a clean environment. Meaning I'll be doing the drilling and tapping with the bike on the Abba skylift... I intend to flush with old oil after I've done the work to try and catch as many particulates as possible following the drilling. But, we will see... Not looking for advice, just creating this thread as I don't care about making mistakes and would rather note it down incase someone finds them selves in the same spot. The kit should be here by the end of the month, I'll update as and when I've done the work.
Sorry to hear about that. Hope that you have success with the thread repair and manage to get the swarf out afterwards OK.
I reckon that the hard part will be to hold your drill accurately & firmly enough so that the hole is perfectly aligned to the original axis and have good control. It'll be quite a large tapping-drill diameter.
Do keep the group updated on your progress. Not to allow piss-taking, but genuinely interested to know how this works out. I've done small threads before, successfully, but a sump plug thread is miles bigger and more awkward if you attempt to to do it with the engine in place in the bike.
You are draining the oil anyway, so rather than try to do it upside down I'd be tempted to remove the fuel tank as well and lay the bike on it's side on an old mattress to give easy access to drilling the hole.
Good luck. Might be worth fashioning some sort of a jury rig for the drill to ensure you go in at a constant and correct angle. Doing it by eye with the engine in situ is a little sketchy, even with a steady hand. Most sump plugs only require a few Nm of torque, which is why I tend to use the smallest torque wrench to hand, so there is less moment and it's not as easy to overdo it. Might be worth having yours calibrated as well. Not expensive and worth it for the peace of mind, especially on the smaller fasteners, which if OEM, will round off at the merest whiff of tightening/loosening, as most are made of Swiss cheese.
I did a spark plug thread on my z400 and it went surprisingly well admittedly I wasn’t working upside down though.
You can hire a magnetic base drill for 30-40 quid a day which would give you drilling stability, and could also be used to walk in your tap at the same angle if you turn the chuck manually. Would just need to work out what you will affix it to (arm of the workshop stand, home made plate clamped to bike etc)
Grease on the end of the cutting tool caught most of it and then I blew the cylinder out with the air line which got the rest. It was a few years ago and it’s been absolutely fine since doing it.
All really good advice, I'm not sure on how I'll do a jig but I'll certainly be taking my time and will look into making one. The thread inserts arrive tomorrow, I think I might try on Sunday but I have other stuff I need to get to first
If they are like the thread inserts I've used, you don't tap the hole. The insert cuts a new thread as it goes in. I used a bolt with a lock nut to hold and place the insert...they require decent torque to cut their way in.
I did a dry run earlier on the abba stand. I have a very good position and even a chair to sit on whilst doing the work. As for a jig, I think I've for a solution and a fairly easy one but I'll see how it goes tomorrow when the parts arrive. @The Royal Maharaja - the kit I've ordered comes with drill bit and tap, the inserts are not self tapping. Still, good to know as I've got plenty of life left in me (here's hoping) so no doubt I'll find my self in a similar position in 20 years from now
Freshage old chap, I'm a Ducati engine idiot so please feel free to ignore my ramblings. Do you possess a phone endoscope, they can be cheap and invaluable occasionally. Then I got thinking, yes I know I shouldn't. Can you get access to that plug area from above with the endoscope from say the breather opening or oil filler to check all the swarf is removed. Plenty of grease on the tap will ensure its cuttings are held out of harms way. Maybe. Flushing with the old oil is a great idea but I'd still want to see what's inside. Good luck fella. Upt.
I did my VW 2.0 diesel glow plugs in situ. I lathered the drill bit in grease and drilled slowly same with the tap. Kept everything out of the cylinders Used a vacuum cleaner also just in case No idea what bike it is but if it's 916 etc then take the inline filter out at the side you should be able to see the bottom of the engine
Surely Any swarf in the sump will get caught by the pre pump filter as the oil path is sump > pre pump screen > pump > post pump filter > oil pathways > drip back down into the sump.
All good advice here. I've had issues with various stripped threads at work and have got away with going up a size on the taps without drilling. Using a helicoil kit was also a good option. The scope down the oil input is great idea . Good luck buddy
