85 250R front sprocket nut

[JOEY11]

Can someone tell me what socket size the front sprocket nut is? Most of my tools are at my parents 3hrs away and I need to buy a socket for the nut.

[shortline10]

If it’s still the OEM bolt it’s a 12mm

[JOEY11]

Thanks. I wasn’t thinking and got it mixed up with my ninja that’s got a large nut for the sprocket. I finally got to work on it today and I brought my metric tools and planned on torquing the head and base nuts and the previous owner used standard size nuts! I’ll bring my std stuff and mess with it tomorrow so I can finish breaking in the top end. Every other bolt/nut on it is original metric except them. I pressure washed it and went over it and replaced some missing or old bolts. It’s coming along and will be a rideable trike soon.

[floydechoes2000]

If somebody did use SAE nuts on the head that means they either hacked them on there (most likely) or they tapped the cylinder to accept SAE studs. (who would bother to do that?)

I'd go over that machine with a fine toothed comb. Good luck!

[yaegerb]

X2......wtf you dealing with bud. Standard on a metric sprocket. What you talking’ bout Willis?

[JOEY11]

Maybe I was there too long and my eyes were playing tricks but I tried all metric sizes and they were too big or small but I’m working on it again today so I’ll check again. They’re not the standard acorn nuts, it’s got standard open nuts on the head. All the other hardware looks to be original 85 except the base and head.

[JOEY11]

I don’t know what I was doing yesterday but the nuts are indeed metric and were torqued properly. I changed the plug, crankcase oil, and took the forks off to send out for refreshing. I’ll replace the chain/sprockets, rear brake reservoir, brake pads, front m/cyl, billet exhaust flange and springs, clutch cable, chain sliders/rollers and a few other things and it should be ready to rip. It’s got grey Maier fenders on it if anyone wants to trade me their red fenders. I like them but I’m more into the plain red look.