The engine required a full rebuild when acquired.
The left hand crankshaft mainshaft was badly worn. The main bearings, gearbox bearings and piston rings were worn.
However, the clutch components and gearshafts were sound. The total cost of the engine rebuild was £200.
The fork seals were blown and the suspension bushes were worn. Cost £25.
The rear cowling was cracked, probably the result of a careless person trying to manoeuvre the bike.
The tank paint was tatty. Respray cost about £80.
Indicators failed to work. Broken wires inside the loom. Replaced the wires.
The RD125LC was the predecessor to the TZR125. The RD125LC mk2 and mk3 had TZR125 instruments, wheels, exhaust, forks and 'bars.
The exhaust note sounds beautiful and throaty with the standard exhaust system.
Yamaha have done well with this machine, with regard to the attention to detail. Everything fits well and the components are of high quality.
The engine employs a broad range of useful torque. The motor will pull well in sixth gear at 30mph.
The engine is responsive thanks to the YEIS (Yamaha Energy Induction System).
Many people who have owned a RD125LC, have informed me that they are capable of exceeding a "ton".
The ride is good with good damping from the forks.
Some of the components are a hassle to remove. For example, removal of air intake and carburettor requires removal of rear shock.
Maintenance in general is fairly easy.
Forks don`t need to be removed in order to change the oil. The engine is accessible without any dismantling work. Therefore carrying out the cable adjustments etc is a breeze.
The RD125LC may not be as glamorous as the latest Aprilias or Cagivas, but is a lot more durable and less expensive.
Yamaha used to sell an model called the RD125 in the US back in the 70's.
Is this a similar motorcycle?
With regards to the above question, the RD125LC described in the main text is completely different to the RD125 that was available in the seventies. In fact, the seventies RD125 was the predecessor to the RD125LC, and was known as the RD125DX. The RD125DX was more of a commuter, and had an air-cooled twin two stroke engine that was available between 1974 and 1982. The RD125LC was introduced in 1982, and was more of a sports bike that was restricted to comply with the new learner laws, introduced to the UK in January 1981.
The RD125DX is a beautiful machine, although quite rare now.
The RD125DX was not a commuter bike. It was an all out sports bike. (using the technology of the day). It revved to about 10,000 rpm and had a top speed of almost 80mph.
It had 16bhp and was later restricted (after 1981) to 12bhp. It was a reed valve 125cc 2 cylinder air cooled 2 stroke. It was slower and less powerful than an unrestricted RD125LC because it was air cooled rather than liquid and it did not have an exhaust power valve.
However, you have to have passed your motorcycle test by 1981 to be allowed to ride a 125cc bike with more than 12bhp, unless it was registered before August 1st 1981. This meant that you could legally ride either a full power (16bhp) RD125DX, if it was first registered before Aug 1st 1981, or you could ride a 12bhp RD125LC if it was registered after that date (all of the RD125LC's were made and registered after that date).
So the fact that the RD125LC could produce almost twice as much power as the DX was irrelevent. The market it (RD125LC) was aimed at in the UK was the learner rider with a provisional license who was restricted to 12bhp. If you derestricted it to unleash it's full potential, you had to technically pass your motorcycle test first. This means that technically speaking you are better off, in terms of power and performance, with the RD125DX (if registered before 1/8/81) than with a legal RD125LC.
Of course if you break the law and use a derestricted RD125LC, before you have passed your test, then you are better off with an RD125LC. I have never heard of anyone ever being charged with riding a derestricted 125, but anything is possible. They could stick it on a dyno and test the power. The only reason they would have to do that though is if you were stopped doing 100mph; there's no way to squeeze that out of 12bhp. I guess even then it's highly unlikely they would test the power output; you'd be in enough trouble anyway.
The RD125LC (all three incantations) were 12bhp water cooled 2 stroke single. They were restricted to get them down to 12bhp; the full power unrestricted models were almost 30 horsepower and good for mid 80's to low 90's. With a small amount of tuning they can do the ton. With a small amount of tuning, i.e. exhaust and KN air filter, they will produce between 30 and 32bhp.
Me and my brother used to hack about on a 1984 RD125LC, we had it up to 27BHP and we were using it on Provisional Licenses. We never had a 100MPH out of, but did get it up to 98MPH downhill on the A1. In the end my brother dropped it at 60MPH, and it carried on sliding on a wet road straight into a crash barrier where it burst into flames. That was the end of it, we had not bothered to register it so we just left it where it fell. Happy Days.
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