Yamaha FZ-09 Forum banner
1 - 12 of 12 Posts

·
Registered
Joined
·
957 Posts
Discussion Starter · #1 ·
So, my brother in law passed away near the end of last year. He has a mid 90s YZ125 2-stroke MX bike that is still at my sister's place on her porch. It's been run hard and it's currently not running. According to my sister, the story she got from Chris was that he was out riding with some friends in a big field somewhere last fall when he hit a jump. On landing the engine just died and wouldn't fire up again with the kickstarter. He said he thinks it just needs new plugs. My sister said if I can get it running again I can have it. But is a 2 stroke 125 MX bike too much for someone who only has street experience and no dirt experience whatsoever? And is it worth trying to get it up and running again?
 

·
Registered
Joined
·
159 Posts
For sure.

2 stroke MX bikes are very easy to work on and repair - about the easiest thing out there. I doubt it is the plugs from the story above - no matter what it is - it is normally an easy fix. I have even completely rebuilt one of those motors myself and I am not one to open a motor normally.

As far as riding it - if you can ride an FZ09 you will have no issue with the YZ125 - but like all 2 stoke MX bikes the bottom end is dead - then when the revs get up there - they scream. Unless you are very light, the 125 won't get you into any trouble.

Kirk
 

·
Registered
Joined
·
349 Posts
So, my brother in law passed away near the end of last year. He has a mid 90s YZ125 2-stroke MX bike that is still at my sister's place on her porch. It's been run hard and it's currently not running. According to my sister, the story she got from Chris was that he was out riding with some friends in a big field somewhere last fall when he hit a jump. On landing the engine just died and wouldn't fire up again with the kickstarter. He said he thinks it just needs new plugs. My sister said if I can get it running again I can have it. But is a 2 stroke 125 MX bike too much for someone who only has street experience and no dirt experience whatsoever? And is it worth trying to get it up and running again?
It sounds like it just needs some cleaning up - 2-strokes can get messy -- check the Carb Bowl - I bet if you take it to a local shop they could get it up and running in no time. YZ250 carb bowl draining - Yamaha 2-Stroke - ThumperTalk
 

·
Registered
Joined
·
957 Posts
Discussion Starter · #4 ·
For sure.

2 stroke MX bikes are very easy to work on and repair - about the easiest thing out there. I doubt it is the plugs from the story above - no matter what it is - it is normally an easy fix. I have even completely rebuilt one of those motors myself and I am not one to open a motor normally.

As far as riding it - if you can ride an FZ09 you will have no issue with the YZ125 - but like all 2 stoke MX bikes the bottom end is dead - then when the revs get up there - they scream. Unless you are very light, the 125 won't get you into any trouble.

Kirk
So you're saying it basically runs like my old 600? Had a ZX6R before the 09. Yeah I'm about ~200-210 or so.
 

·
Registered
Joined
·
196 Posts
Clean carb, fresh fuel and a plug should be all it needs to run. Check usual stuff like air filter and trans fluid before running it as well. If it was ridden hard it may be down on compression and need a piston. You'll know if it takes a lot of kicks to start it and is down on power.
 

·
Registered
Joined
·
4,424 Posts
That is one of the best dirt bikes that you could ever get you hands on. Two strokes teach you throttle control unlike any current street bike can. Piston and rings are a breeze to change. Crank bearings are another issue, but still not that hard to learn how to split the cases. Yamaha dirt bikes are known to have issues with the black ignition box failures. Pull the plug out, touch it to the metal cylinder with the cap on, and see if the electrode gets a spark when you crank down on the kick lever.
 

·
Registered
Joined
·
22 Posts
If it kicks over, not a big deal. 2 strokes are pretty simple, gas or spark. Probably just a stuck float, plugged jet, or something else that's a quick. Nothing like a 4 stroke. Repairs are cheap DIY. And yes, an older 125 2 stroke is a perfect first bike. No bottom, keep it in the power-band and hang on. Mostly bullet proof except for clutch job and piston/ rings now and again.
 

·
Registered
Joined
·
619 Posts
landing from a hard jump, i bet something came unplugged or broke. Check it for spark as Doug said. if it has spark, clean the carb and ride the hell out of it.
 
  • Like
Reactions: DNFDOUG

·
Registered
Joined
·
962 Posts
Yeah - check for spark, check for compression, clean the carb... You'll need new floats, needles and jets. I used to do some hard landings, and it could have cracked a condensor, slipped a point, or had the coil come loose. The carb's float might have bent on landing, the reed valve might have broken, the carb may have come loos in it's boot...
 

·
Registered
Joined
·
155 Posts
I bought an 06 (maybe 07? I forget) YZ125 as a toy and have been hoked ever since. I wont even touch 4 stroke dirtbikes anymore. Im even diving into 2 stroke road bikes. My godfather has a H1 and H2 plus a GT and he just restored a RD. Im super jealous and a looking into one.
 
  • Like
Reactions: RichBaker

·
Registered
Joined
·
730 Posts
More like a 250 4- stroke with less bottom end...
Go for it!
So you're saying it basically runs like my old 600? Had a ZX6R before the 09. Yeah I'm about ~200-210 or so.
 

·
Registered
Joined
·
730 Posts
No points or condenser.... electronic sign since the late '70s....

Shouldn't need new carb parts either. Just a good cleaning and some troubleshooting, maybe.

Yeah - check for spark, check for compression, clean the carb... You'll need new floats, needles and jets. I used to do some hard landings, and it could have cracked a condensor, slipped a point, or had the coil come loose. The carb's float might have bent on landing, the reed valve might have broken, the carb may have come loos in it's boot...
 
1 - 12 of 12 Posts
Top