running a bike without oil

**motorbyclist** · 2nd December 2007, 22:58

so i've got an old '85 TT250 that gets used whenever dad goes riding or i have non-riding mates over - so maybe 5 times a year. she was a bit of a project when we bought her, nicknamed "puff the magic dragon" for all the blue smoke she put out, but since we've gotten her right she's been mint; always started within 3 kicks even after sitting in the shed for a few months.

a mate broke the front brake reservoir/master cylinder (single unit) hitting a tree, and today i finally got around to putting a new one on.

having successfully finished this i took her outside, squirted with detergent and hosed off any brake fluid that was spilt, started her, and then put some crc on the fuel tap/carby and put a quick squirt of lube on the chain while she warmed up. i got on, stalled it, assuming she was cold i roll started due to laziness and did a quick test of the brake then rode back up to the shed. i thought there was some funny noises that should've stopped once the oil got back up into the head etc, so i turned her off, unscrewed the dipstick and found it was only to fill but noticed the flywheel looked awfully dry....

cleaned the seeing eye and had a look...

tipped the bike right over onto the seeing eye side and i think it's safe to say there was NO oil in there whatsoever

engine had been running dry for maybe 3 or 4 minutes

after refilling and running for another minute to get the oil circulated there is still a bit of noise coming from the head/cam chain, and being used so rarely i can't remember if that's normal or not....

so, does anyone have any advice/experience as to what damage i may have likely done? she didn't seize and she still has her compression (lost the decomp cable at some point). i'll ride her tomorrow maybe to see what she's like.

no idea where all the oil went, but i think last time it was ridden it must've been low on oil then too... there is a leak, but only a slow one from a broken gasket at the top of the flywheel cover, and no oil marks under the bike.
moral of the story: always check for oil before starting bikes

**motorbyclist** · 2nd December 2007, 23:02

oh, i might add that i was looking at selling her for those still interested

not used enough and i really need the cash/room in the shed

**xwhatsit** · 2nd December 2007, 23:25

Originally Posted by motorbyclist

moral of the story: always check for oil before starting bikes

Damn straight.

At a guess -- from looking at the spare parts collection I've amassed from myriad shagged out RSs -- the cam bearings and journals will be shot. Cam lobes too, along with the rocker surfaces.

I've seen a the bore from an engine that was supposedly run out of oil; not exactly silky smooth, but then again that seized, yours did not.

TT250, from seeing photos (and Wired1's threads) seems to be the sort of simple robust thumper engine that would take that sort of abuse and carry on going. My 250RS engine is probably slightly more fragile, but still took a couple of exhaust valves in the piston (two dents in the top) and shit-loads of swarf into the bottom end, and is running as well as ever (175psi compression

) with a good flushing of the oil. Still the same piston. So you could probably get away with it, might just be a bit rattly

Running a bike out of oil to me seems the ultimate crime, lol. Hell of a way for an engine to die. Entirely preventable too, by a simple oil check every time you use the bike. You won't forget again

**Ixion** · 2nd December 2007, 23:54

Not good, but probably not as much damage (if indeed any) as some might expect,

From memory the old TT250 engine is a roller crank. And even if all the oil were drained out, there would still be an oil film on the bearing surfaces , which would provide lubrication for a surprising length of time. I think the cam journals are plain metal though so they may have suffered. But, three or four minutes is not very long.

On engines which do not have plain crank bearings, the most significant danger in running with a low oil level is localised overheating. An aircooled motor (and a water cooled one, too, though to less extent) relies quite a lot on the oil to dissipate heat. Not really an issue here, with the short time, so you may very well have gotten away scot free.

At one time various oil and additive manufacturers used to have a pubicity gimmick of filling a motor with their product, draining it all (and the oil) out, and running the drained motor at high revs until it blew up. The length of time they lasted was in some cases quite remarkable - many many hours.

Oil? We don't need no steenkin' oil.

**motorbyclist** · 3rd December 2007, 01:11

Originally Posted by xerxesdaphat

TT250, from seeing photos (and Wired1's threads) seems to be the sort of simple robust thumper engine that would take that sort of abuse and carry on going.

lol let's say this isn't the first time this has happened... a few years ago, right after it's initial rebuild my brother was riding it and also wasn't running enough/any oil - can't remember the exact details, but after at least 10 minutes (maybe as much as 30) one of the valves jammed and got struck by the piston - surprisingly the valve was still good once in was straight again but the piston needed replacing.

engine has been damn reliable ever since that was fixed, so hoping i didn't hurt it this time around

**imdying** · 3rd December 2007, 09:15

Long term, it will have totally shagged it. Cam and crank bearings will now be toast. The best thing to do is to sell it quickly.

**Ixion** · 3rd December 2007, 09:27

Cranks a roller, like a two stroke. It should be fine, there'd be as much residual oil on it as a two smoker ever gets. Cam may be another matter, but it's only half engine speed, and flood lubes, not pressure.

If it had been a shell crank (like the SV) that would have been another matter. Toast for sure.

**FilthyLuka** · 3rd December 2007, 09:57

yeah, good ol' 250 thumpers... gotta love em

**Wheeliemonsta** · 3rd December 2007, 11:43

Gidday,
Crank on those old girls is a roller bearing jobby so it may have escaped unscathed...

Damage will be mainly confined, noise wise, to the cam & rockers which were a notorious weak spot in those engines anyway...

Pull the top off & have a squizz I'd say - you may have been lucky

If it hasn't thrown a wobbly yet chances are it won't

Apart from the delecate top end, they were a pretty robust old bucket of shite...

Cheers