I am very interested in getting a biggish street and trail motorcycle of 300cc or over.  The thing is I don't have a lot of drving experience and I want to learn how to drive with a bike I'm not afraid to damage.  Someone I know is selling a very old (1979 I think) RM125 dirtbike.  It isn't perfect but it starts and goes.  He only wants $400 Canadian for it.  Is this the way to go for learning how to ride?

Should you buy it? Hell yes! Suzuki made THE dirt bikes in the 70s. Forget the CRs and YZs.

That is the perfect trail/dirt bike to learn on. I learned on an RM80 and then moved up to an RM175.

I was a bike mechanic for 19 years in Canada. Ive owned several dirt bikes and believe me that is NOT a good starter bike. 125cc motocross bikes in that era were notoriously peaky. That means, while wickedly fast, they have no low-end power. All 20 or so hp. is located way up in the rpm range, spread across maybe 2000rpm at 10,000 to 12,000rpm. They are much harder to learn on than a larger motocross bike like a 250 or 4-500(I believe Suzuki's open class was 400cc's then)which has plenty of low end power. Larger bikes can be driven like a trail bike slowly putting along. While the 125(of that era)
needs to be on the gas all the time.
While it sounds like a good deal, most dirt bikes are horribly neglected and driven very hard.
See if you can find the service manual. Read it. Motocross bikes are hi-tech race pieces, meant to be re-built every two races. Harldly anyone cares for them this way.
You would do better with an xr200/350, xt 350 four-stroke.I could go on and on... JMHO
BP
While it runs, its probably in sorry shape.

captain pooby is exactly right. better a 4 stroke to learn on.
willy

I third pooby Either a 4 stroke or an enduro 2 stroke in the 250cc range.

Captainpooby's advice is 100 percent accurate.  Just follow his advice and you'll do fine.

A 22 year old 125 is not going to be that reliable and definitely pipey.

Stick with a thumper.  Just about any stock XR will be about as reliable as a hammer.

Well I will be damned!!!

I had a '79 RM125. Great bike. Ran the shit out of it (and rebuilt the engine more time than I can count). Finally dropped it off at the junk yard after I melted the piston and destroyed the gearbox. Learned one important lesson, when changing altitude RE-JET the carb.

I do NOT recommend this bike as a starter bike. Captainpooby is 100% on the mark. The bike can be extememlly fast, I was clocked doing 80 mph on the side of the road one time (and I was taking it easy) by a cop.

Low end power sucks, but when it revs hit the powerband, hang on, it shoots like a rocket. Lost the bike on the first day out when it hit the powerband. It went without me for a good 100 yards before it fell over (I accidently shifted up a gear as I went off the back).

I used to laugh my ass off watching the gezzers that were try to learn on their dirtbikes. Bike going one direction, them another. Watched many of them break an arm or a leg and have to hobble home.

If you want to start out, go find a nice enduro thumper (4 stroke) if you want to learn off road. Or even better, go take a class! There are many places that actually have bikes for you to learn on. They have class room, then road room. They will teach you faster and better than you could on your own. Plus, if you find out that you really don't like riding, you are only out of the cost of the class. If you buy a bike... you have to sell it, generally at a loss.

I would not recommend it, I had a 1982 Yamaha IT-175, it was a great bike and had a lot of power, I picked it up for $800 and it had a new top end, and looked very good.  They are light and have good suspension for a trail bike.  Another thing to look at would be a RMX-250 (Suzuki) or KDX-200 (Kawi), these would be great trailbikes and have good USEABLE POWER.  The problem with motoscross bikes, especially the 125's is that they are basically on or off the power.  Also depending on how big you are you may need a bigger bike.

oh yah that was my first big bike i rode i couldnt even touch the ground then.my uncle started the bike and held it up as i took off rode circles with that bike til he was ready to hold the bike as i came to a stop.or found a rock to touch ground with.I too owned one along with a 84 kx 125,88 cr250(one hell of a bike too).for 400 get it.