I broke it.

[Hadyn]

So today I decided that I would change my oil. I used the ninja250 wiki and followed their procedures, everything went swimmingly until I torqued down the oil drain plug. I had my torque wrench set for 14ft-lbs, and had already correctly torqued down the oil filter cover. I hand-tightened the drain plug and began to torque it, but it never got tight. There was no real resistance, no sudden snap, nothing; the bolt just kept spinning.

I have no question that I stripped the hole, but I have no idea HOW the hell I did it. I re-used the crush washer (unwise yes, but the local parts shop didn't have it and I had the time/space for an oil change today) and when I backed the bolt out it was mangled all to hell. I managed to actually shear off the threads, you can see them at the top of the second image. What the hell did I do? Did it just get cross-threaded? Also, I'm guessing that's not how the drain plug hole is supposed to look. Is it time for a new engine casing, or can it be re-tapped/counter-bored and repaired?


As a side note, something is dripping oil onto my left exhaust pipe, and ultimately onto the inside of the lower fairing (last picture). I've tracked it down as coming from whatever's in the second to last picture. Is that a big deal?

[Snake]

Looks like you did cross thread the bolt which caused it to stripp.

The second to last picture is the water pump housing.. I would check all the bolts to make sure they are tight and check the water pump housing and sorounding area for any cracks.

[dimeified]

are u sure its supposed to be ft pounds and not inch pounds? im not really sure i just torque by "grunts". oil drain bolts i tighten the bolt without flexing, then i give "1 grunt" to lock it in place.

[kkim]

How tight did it feel when you were torquing it? Could it have possibly been that the torque wrench didn't click and you kept on tightening?

That crush washer looks... CRUSHED!!!

Perhaps the oil drain hole was fubared from an earlier oil change and was already stripped??

I believe you can helicoil the oil drain hole.

[Hadyn]

Originally Posted by kkim

How tight did it feel when you were torquing it? Could it have possibly been that the torque wrench didn't click and you kept on tightening?

I had just finished torquing down the filter bolt to 14 foot-pounds, and the drain bolt was nowhere near 'tight.' I was still using one hand to tighten it down and expected much more resistance, but it just kept spinning in place. I even followed the advice on the wiki and tested the torque wrench on the wheel nut of a car to learn how it behaved when it reached the torque limit.

EDIT:
is the drain plug hole supposed to be equally deep all the way around? Mine's definitely not, it almost looks like it was broken off.

[kkim]

Originally Posted by Hadyn

is the drain plug hole supposed to be equally deep all the way around? Mine's definitely not, it almost looks like it was broken off.

dunno, but it looks like if you remove the filter assembly, you might be able to see/feel the drain hole to see what's up.

[KELPHYN]

I to think you should be able to heli-coil it. Also I half no experience with pre-gen's, but don't they have another drain plug closer to the back of the engine, like the new-gen's ?I looked in my manual for the new-gen's and the plug you're using is listed as a drain plug, but not the one you should be using for regular maintence. For that you should be using the rear one. But like I said I've never looked at a pre-gen.
On your side note about the oil dripping on your pipe and the oil build up on the left fairing. It looks like chain lube drippings from your front sprocket. I have the same thing.
Good Luck with the threads. I'm sure it will be a PITA but fixable.

[kkim]

Calvin,

Pregens have only that one drain hole.

[KELPHYN]

Now I know. Thanks Kelly.

[Hadyn]

Originally Posted by kkim

dunno, but it looks like if you remove the filter assembly, you might be able to see/feel the drain hole to see what's up.

I tried this and couldn't see outside the oil filter hole-thing, but in taking the oil filter back out I learned that I probably stripped that hole too. I thought I had torqued the filter cover bolt down to 14ft-lbs, but when I was un-screwing it I could almost do it by hand. Can that be heli-coiled too? If not, how difficult/expensive is replacing the lower casing?

[kkim]

damn... that doesn't sound good. maybe there's something up with the torque wrench you're using? isn't the filter bolt the long one that threads way up into the cases?

I can't answer the cost issue, so I'll defer to someone with more lower end engine rebuilding expertise than I have. I bet one of the guys in the race section might be able to answer your questions... they're constantly breaking their engines.

[tiggen]

Originally Posted by kkim

How tight did it feel when you were torquing it? Could it have possibly been that the torque wrench didn't click and you kept on tightening?

That crush washer looks... CRUSHED!!!

Perhaps the oil drain hole was fubared from an earlier oil change and was already stripped??

I believe you can helicoil the oil drain hole.

Yeah, I'll bet the guy before you did the damage. And yes I hear that helicoil is the best way to go, although I don't have any experience with them to share. When I torque my bolts (04) I'm always surprised by how little force 14.5 ft-lbs is (that is the correct torque, btw).

I'll also bet that the crush washer on your water pump drain bolt is "crushed" like the one from the oil drain bolt and not doing it's job. Might want to check your coolant level too.

[dimeified]

Originally Posted by tiggen

Yeah, I'll bet the guy before you did the damage. And yes I hear that helicoil is the best way to go, although I don't have any experience with them to share. When I torque my bolts (04) I'm always surprised by how little force 14.5 ft-lbs is (that is the correct torque, btw).

I'll also bet that the crush washer on your water pump drain bolt is "crushed" like the one from the oil drain bolt and not doing it's job. Might want to check your coolant level too.

if you helicoil get a kit that's long enough for the bolt so you dont bottom out at the end.

[bob706]

Just a shot in the dark but were you reading the right side of the torque wrench? I think most have two scales on them and if you had the wrench set to 14 on the metric scale then you were somewhere around 100 ftlbs which would explain your situation.

[tiggen]

Originally Posted by bob706

Just a shot in the dark but were you reading the right side of the torque wrench? I think most have two scales on them and if you had the wrench set to 14 on the metric scale then you were somewhere around 100 ftlbs which would explain your situation.

Don't want to decimate you but...

14 Nm = 10.3 ftlbs

[bob706]

Originally Posted by tiggen

Don't want to decimate you but...

14 Nm = 10.3 ftlbs

My large wrench doesn't read Nm. It reads M. I should have denoted that. Perhaps the OP has a similar torque wrench.

[Hadyn]

I'm positive the wrench was set for 14 foot-pounds. I even took a picture.
I did manage to find a parts bike for nearly nothing, I'll be picking it up as soon as I can make it up to PA and hopefully salvaging the crank case from that. I'll assess the damage to the screw threads of the oil filter bolt hole tomorrow, maybe I'll try to helicoil it anyways.

[kkim]

yes, by all means try to work with what you have now and repair it, if possible. Helicoil, for sure.

GL man...

[Plasmatoast]

Doubt you will find a helicoil to fit it at a local store.
I ended up Drilling and tapping my pregen, believe i ended up with a 13mm instead of the 12mm hole, It was the next Size up But not sure the exact size, its been a while.

after that i purchased a New Gen Oil Drain assembly and used that .. just remove the Metal screen cover and bolt the new assembly on. Works perfect

[tiggen]

Originally Posted by bob706

My large wrench doesn't read Nm. It reads M. I should have denoted that. Perhaps the OP has a similar torque wrench.

Bob, sorry, I couldn't resist the opportunity to use the word decimate literally. I was just trying to make a joke (admittedly a bad and dorky one), prob. should have used smilies. I figured you probably weren't talking about Nm anyway.

[Alex]

:groan:

[bob706]

Originally Posted by tiggen

Bob, sorry, I couldn't resist the opportunity to use the word decimate literally. I was just trying to make a joke (admittedly a bad and dorky one), prob. should have used smilies. I figured you probably weren't talking about Nm anyway.

I was gonna say that too. Decimate isn't used alot. I got the joke so no worries.

14ftlbs would not decimate a crush washer like in the photo. 100ftlbs would do the trick.

+1 for tapping from 12mm to 13mm. Don't know if I'd trust a helicoil there.

[Hadyn]

Good news! I didn't strip the oil filter hole, I just destroyed the filter cover. Also, the wall of the drain plug hole is fine, so to get her running again, all I need is:
Oil filter cover
13mm Tap + bit
13mm oil drain plug
13mm crush washer

Now, any advice as to how to lift the bike up high enough to get a drill under it?

[kkim]

strip off the fairings and carefully lay the bike on it's side?

[Plasmatoast]

just use a car jack and some wood blocks under the front of the engine. use a rear stand if you have one, and a friend to hold the bike steady

[Hadyn]

Originally Posted by kkim

strip off the fairings and carefully lay the bike on it's side?

I was considering that, but then all the metal shavings would fall into the engine. I'm sure they would get picked up by some screen or filter somewhere, but I'd rather not risk it. I'm thinking a nice big 4x4 under the center stand and another one under the front wheel would get it up high enough.

Also, I can't seem to find a suitable 13mm flanged bolt to serve as a new plug if I were to tap it, and I'm not sure how much bigger I could go without risking the integrity of the hole. I would helicoil it, but it looks like the oil drains from that opening in the wall of the hole, so a I think a helicoil would block it.

But the oil doesn't have to drain out of that hole, right? Could I helicoil it, switch to the new-gen oil screen assembly, drain it from there and just never touch the normal plug again?

Thanks guys, you've been a huge help!

EDIT:
Consulted with a more mechanically-inclined friend, he said that I shouldn't even need to switch to the new-gen screen cover because the oil can drain through the helicoil. That might be a future upgrade though.

[kkim]

do you have some sturdy rafters that can support the weight of the bike? I'm serious.

Yes, draining through a helicol should be no problem.

[Hadyn]

Originally Posted by kkim

do you have some sturdy rafters that can support the weight of the bike? I'm serious.

Hmmm... The pre-gens are what, 364lbs wet?
I think the rafters in my garage could do it.

[kkim]

you could pull the front end of the bike up by using some tie downs/rope looped over the rafters. connect to the bike at the handlebars. If you do it his way, make sure to stabilize the bike somehow under the front tire once it's raised just in case the straps/rafter fail.

That should raise the bike enough for you to work under it. If not, you could also use some jackstands under the footpeg mounting bracket area or swingarm to further raise the bike in conjunction with the front end lift method.

[Hadyn]

I ordered the parts to fix her last week, but the oil filter cover is on backorder.
And of course, the two weeks my bike is broken are the nicest two weeks of perfect riding weather I've ever seen. I bet when I finally do get back on two wheels there will be a typhoon or a freak midsummer snowstorm or something.
Posted via Mobile Device

[Hadyn]

I'm bumping this with an update, and another question.
I drilled, tapped, and helicoiled the drain hole. After cleaning up the threads on the bolt itself, it fit right in and took the 14.5 ft/lbs perfectly. I put the new oil filter cover together with the filter assembly and put that back in, and torqued it to 14.5 ft/lbs.

I filled up the oil to just above the fill line (started with 1.5qt., ran it, added more, etc) and rode home. The next morning there was a little oil spot (~5 in in diameter, but only about a quarter-sized 'puddle') under the bike, but the oil level was still reading full. I noticed that every time I parked it at my apartment, there would be a similar-sized spot, but when I park at work for 8 hours (minus a 5-minute ride to get lunch) after a 15-mile ride, there's no spot at all. And just to make it more confusing, yesterday after a pretty rigorous ride, I parked for an hour and found an oil spot under the bike when I went to move it again. The oil is definitely coming from the drain bolt/hole. I tightened the bolt another 1/8th turn while the engine was hot, but it still dripped just a bit.

Here's what I suspect:
The lower half of the crankcase, helicoil, and drain bolt are heating and cooling at different rates. When the bike is hot, all the parts have heated up, expanded, and are creating a nice seal. When I park the bike at work, I park it outside in the sun, so it stays relatively hot. When I park the bike at night, (or in the shade, as I did after the vigorous ride) the temperature drop cools and shrinks the oil bolt, helicoil, and crush washer before it cools the crankcase, allowing the still-warm oil to seep out of the cracks.

Does that seem plausible, or am I crazy? Also, is a little oil leak something to be concerned about, as long as I'm checking my oil (which I do before every ride anyways) religiously and adding as needed?

As a kind of related question, I know I've read that the 250 engines, by design, will burn oil when they're pushed hard, but how much is 'normal'? I went on another ride on Saturday, about 10 hours worth of pretty spirited riding, and when I checked the oil before another ride on Sunday, I was down to below the middle of the sight glass. Is that something to worry about any more than my little oil leak?

[nick2049]

Originally Posted by Plasmatoast

i purchased a New Gen Oil Drain assembly and used that .. just remove the Metal screen cover and bolt the new assembly on. Works perfect

Any idea what the part number is for the New Gen Oil Drain Assembly?
I also stripped the threads in my drain plug and was thinking about welding a new plug on. Is there any downside to that approach that I'm not seeing?