DARN the Bad Luck! (Honda CR125R Dirt Bike Engine Seized)

[Lotsokids]

TWO DAYS AGO I bought a 1989 Honda CR125R so I could go dirt riding with my son, who also has a Honda 125 dirt bike. I paid the equivalent of about $500 for it. Well, I tested it before I bought it, and everything was fine (except hard starting with the kick start). Went riding today and the ENGINE SEIZED. That sucked. My daughter towed me home with her scooter. I pulled the spark plug, thinking maybe the cylinder liquid-locked with fuel or something, but no. It's frozen. It's a 2-stroke, and I just filled it with properly mixed fuel - about 35:1. Coolant level was good before I rode it.

Now I get to drag it to the shop and get a repair estimate. :bang head:

 

[timpilot]

TWO DAYS AGO I bought a 1989 Honda CR125R so I could go dirt riding with my son, who also has a Honda 125 dirt bike. I paid the equivalent of about $500 for it. Well, I tested it before I bought it, and everything was fine (except hard starting with the kick start). Went riding today and the ENGINE SEIZED. That sucked. My daughter towed me home with her scooter. I pulled the spark plug, thinking maybe the cylinder liquid-locked with fuel or something, but no. It's frozen. It's a 2-stroke, and I just filled it with properly mixed fuel - about 35:1. Coolant level was good before I rode it.

Now I get to drag it to the shop and get a repair estimate. :bang head:

Whaaaaat? Pay somebody to fix a 2- stroke? It's simple like a lawnmower. Pull it apart and pay somebody to bore it out for an oversize piston. Taking it apart and putting it back together is a 1-hour job. If you don't know how, get a free download shop manual. You'll gain valuable skill you should be teaching your son anyway.

 

[jedi-]

Whaaaaat? Pay somebody to fix a 2- stroke? It's simple like a lawnmower. Pull it apart and pay somebody to bore it out for an oversize piston. Taking it apart and putting it back together is a 1-hour job. If you don't know how, get a free download shop manual. You'll gain valuable skill you should be teaching your son anyway.

Agreed, a big bore kit 139cc is only $125 aud . Get it bored out and do the rest yourself

 

[blaxmax]

And put an oil cooler on it- probably low on oil and why it seized in the first place.

 

[Lotsokids]

The problems with doing it myself are:
- I live in Hungary. I don't speak the language very well.
- If I order parts myself, it takes about 30 days to arrive.
- I don't know of any machine shops here and don't even know how or who to ask.
- There is a very good motorcycle mechanic in another village. He charges virtually nothing for labor. He's rebuilt 3 pairs of forks from different bikes for about $45 each pair. Oil and fuel is extremely expensive here, so the fork oil is about $15 / liter. Still a big language barrier. He knows ZERO English.

And put an oil cooler on it- probably low on oil and why it seized in the first place.

I'm a little confused about this statement. It's a 2-stroke. The piston is seized in the cylinder. The only place that would have oil "quantity" is the transmission. Is this correct?

I was riding it on the road with relatively high sustained RPM. The seller said the engine is a rebuilt 1992 motor. I see new sealant around some parts, so I know someone was in there.

 

[caseyjones955]

These do need to be rebuilt every 25-50 hours or so depending on how they are ridden and maintained, that works out to every season or two for an average mx rider. It sounds like it was getting close to shelled when you bought it, low compression can make it hard to start so worn top end makes pretty good sense.

+1 on the home rebuild, they are very simple, everything is easy to reach and the overbore kits should be readily available.

 

[blaxmax]

The problems with doing it myself are:
- I live in Hungary. I don't speak the language very well.
- If I order parts myself, it takes about 30 days to arrive.
- I don't know of any machine shops here and don't even know how or who to ask.
- There is a very good motorcycle mechanic in another village. He charges virtually nothing for labor. He's rebuilt 3 pairs of forks from different bikes for about $45 each pair. Oil and fuel is extremely expensive here, so the fork oil is about $15 / liter. Still a big language barrier. He knows ZERO English.



I'm a little confused about this statement. It's a 2-stroke. The piston is seized in the cylinder. The only place that would have oil "quantity" is the transmission. Is this correct?

I was riding it on the road with relatively high sustained RPM. The seller said the engine is a rebuilt 1992 motor. I see new sealant around some parts, so I know someone was in there.

Yes you are correct--had a brain fart on that one-------I had a 1976 yamaha enduro 400 that if the oil gas mixture was just a little off would overheat and seize. It would take about 15 to cool down and start up again.

 

[Lotsokids]

+1 on the home rebuild, they are very simple, everything is easy to reach and the overbore kits should be readily available.

Again, I live in Hungary. I'm SURE an overbore kit is not available. Plus would I would not know who or how to ask. Ebay UK sometimes has some options for me. But I would FAR rather just pay the mechanic a little money and ride it home a few days later.

 

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Does it have a nikasil plated cylinder?

Sent from my SM-G900V using Tapatalk

 

[06VMAXIMUS]

That old of a 2 stroke bike most likely developed an air leak which caused it to lean out and seize. Make sure you watch out for contaminates that made their way down to the crank.....don't just do the top end and reassemble! Crank seals get hard and crack causing air leaks, as well as base gaskets and intake boots.