A little delicate problem.

redfox

redfox

Hero member
Hi all,

Spotted a Little oil under the SFC1000 today, and upon changing the copper seal on the oil sump plug, horror of horrors, the thread is dead. No way to tighten it to spec.
So, many years ago I did some thread renewal on my former RGS, but what do you good people say to this. Is it possible to insert a helicoil or something better into the sump plug thread?

Oil out of course, but can it be done without removing engine from the bike?

And what size should I get, if at all possible?

Kind regards,
jacques
 
If it's anything like a jota then, yes it can be done. I had a helcoil put in my sump a few years back. With engine in frame. It now takes sump plug from a Suzuki bandit and seems really good and sound. This summer I managed to get hold of a magnetic sump plug that was so incredibly strong that i was worried it might suck the teeth off the gear box one by one. So far it has not done so, but I will be intrigued to examine what is stuck to it when it's oil change time.  Here it is for those who are interested. Apparently the magnets are the strongest known to man !!

https://www.ebay.co.uk/itm/Suzuki-GSF1200-GSF600-Bandit-TITANIUM-OIL-SUMP-PLUG-BOLT-MAGNETIC-M14X1-25-R1F3/261947299044?ssPageName=STRK%3AMEBIDX%3AIT&var=560765902346&_trksid=p2057872.m2749.l2649
 
Same thing happened to my Jota after I'd had the engine out and cases split to replace gearbox bearings. One of the last reassembly jobs was to put the sump plug in and the fucking thread failed. If I'd checked it while the cases were split it would have been a simple job to fix.

Anyway, I fixed it with the engine in the bike. Bored the remains of the thread out and tapped it to a larger size. My memory is a bit hazy on the thread details. I think the original thread was M12 and I went to M14 fine pitch.

I thought about lying the bike on its side so I could get access to the hole, but decided to do the job with the bike sitting upright to make sure any swarf that got inside remained around the edge of the hole. I had a handy wooden box about the same height as the bike lift (actually an engine shipping crate). So I jacked the bike up on the lift, put the box behind the lift with a piece of 1/2" plywood across the gap, then rolled the bike back across the plywood bridge so that the rear wheel was on the box while the front wheel was still on the bike lift. Bike was held upright with tie-downs onto the bike lift at the front end. When the plywood bridge was removed I could sit on the floor directly under the sump plug hole with the drill. I must have made some effort to keep the drill and tap properly aligned. Several ideas come to mind as I think about it, but I don't remember what I did on the day.

I used plenty of Trefolex cutting lubricant on the drill bit and tap to capture most of the aluminium swarf. Then after it was dome I scraped around the inside of the hole with a piece of bent wire with grease on it to pick up any remaining bits of swarf.
 
Thanks Guys. I remain optimistic ;)

Which bike has a larger sump plug? (I'll look into the busuki plug.
If I can retain the original plug size/thread, I prefer that. But it may be a wish only.

Kind regards,
Jacques
 
Standard is M14x1.5, you can tap out to M16x1.5 which is another common plug size.  Doing that saves the complication of fitting an insert which is not really required.
The main thing is to keep the new thread square to the sealing face, I made a jig to bolt onto the camchain access port hole which was a bit of work but worked well. This job is easily botched. 
:o
 
Inside the lower crankcase half there is a casting very close to the sump hole.
I have seen several examples where someone had fitted an oversize sump plug after opening it up. The trouble is that the tap hits the casting and skews the threads.
This results in a sump plug not parallel to the lower crankcase half, and the sealing washer has no chance to stop leaks.
So if I were you I would either make up a jig as Steve said, or remove the crank case and have it machined. This way the casting is partially machined, allowing the plug to fit square.
 
I seem to remember another "thread" on this subject: whatever you do, make sure you do it straight and square
https://www.laverdaforum.com/forum/index.php/topic,42651.msg79570.html#msg79570
 
Grant said:
This results in a sump plug not parallel to the lower crankcase half, and the sealing washer has no chance to stop leaks.
So if I were you I would either make up a jig as Steve said, or remove the crank case and have it machined. This way the casting is partially machined, allowing the plug to fit square.
Click to expand...
Very valid point care and attention and must and as per Steve a jig would def help.
You could always run it out to 15mm as that is first oversize for 14mm sump plug.
https://www.ebay.com.au/itm/OIL-SUMP-GEARBOX-DRAIN-PLUG-THREAD-REPAIR-TOOL-KIT-M15-X-1-5mm-TAP-THREADS-/161058896327
 
breganzane said:
Standard is M14x1.5, you can tap out to M16x1.5
Click to expand...

Yes, that sounds more familiar. Ignore my previous nonsense about going from M12 to M14. I told you my memory was shit. All I could remember was that a 14 mm thread was involved somewhere.  ::)
 
Thanks all,
I'll take my bicycle to a Tool shop asap, after I find out which bikes have M15 and M16 sump plugs.

Cheers,
jacques
 
Hi Jacques,

I bought a set of oversize sump-Plugs with a finer grade of threads for my fathers Triumph BDG 250 H. There are 5 screws each size and I have all of them left over in 15mm.  So - I can send you one if you like.

If you send me your address offline, I am happy to put one or two in a bag and send it over to you. they are not the magnet type, but they are zinc-plated (gold), which I think works well with the alloy. You could simply drill a whole into the underside and glue a magnet into it if you like. I have alloy washers in the according size, too. Next size I have would be 17mm though.
 
Some BMWs have M16 x 1.5 sump plug.
Lots of cars must have M16 too because you can get them at any car accessory shop.
I got mine on ebay. It's a nice blue anodised aluminium one with a magnet in it.
I thought about making a plastic one so it would have softer treads than crankcase, but wasn't sure how well it would cope with hot oil.
 
My first magnetic plug was bought from a BMW shop in Sydney. It lasted for a few years but gradually lost its magnetism.That took maybe 10 years.Seems hot oil isnt the best home for magnets? It was replaced by one from Red with a rare earth magnet that was a lot stronger.
 
May not last long either. Rare earth magnets are sensitive to heat too. Possibly more so than iron magnets. Not sure about the relative temperature limits though, I'd have to consult the oracle (google).

 
I just place a strong, round Neo magnet on the outside of the sump plug, making the whole plug magnetic (if it's steel of course). When the time comes for an oil change, the magnet is taken off, maybe releasing the catch, but it is then in the vicinity of the oil drain hole anyway and gets washed out with the oil flow.
 
Paul H said:
I just place a strong, round Neo magnet on the outside of the sump plug, making the whole plug magnetic (if it's steel of course). When the time comes for an oil change, the magnet is taken off, maybe releasing the catch, but it is then in the vicinity of the oil drain hole anyway and gets washed out with the oil flow.
Click to expand...

Brilliant.
 
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