My Lady in Red- a 1990 Yamaha RX100

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During December 2010, the bike had starting problems. I took it for a

check up to the YASS. They checked up the bike. I thought it would be a

fouled up spark plug so got it changed. The carburettor was also cleaned

up and the electricals also checked.

The mechanic had however told me earlier that the engine compression had gone down

and the engine seizure could take place anytime. It was getting late and so I left with the bike

thinking I would get the work done sometime soon. But enroute home the bike's

engine got stalled.There was a metallic sound - I stopped the engine and

pulled it back home which was about a km away.Since then, I did not have

the time to get it repaired.

Only during first week of January 2011, I took it to my trusted 2

wheeler mechanic Mr Rajabhau Bhole. The bike was opened up and there appeared to be a

crank bearing failure too.The mechanic was showing me all the dried (desert like) parts including

the engine block, bearings, crank,and even the reed valve..Also he said

that if for sometime the oil pump is starved of oil, it can develop faults

and ultimately conk off the mechanicals. I don't remember about such an event, but it has

done 20 years on the road after all.

The engine block and piston were checked at another workshop using lathe machines for probable damages by the mechanic Mr Bhole.



WHATSOEVER. 20 years on and still lugging.

The same piston and engine block were reassembled on the

bike.However the mechanic had expressed his apprehension with the piston

rings and so the rings and the gudgeon pins were replaced.

The bike had just run about 50 K kms in its 20 years with me. It got all

the TLCĀ  always. It was an oil pump failure triggering the engine failure.

As predicted, it was the oil pump that turned out to be the culprit.The

thing did not and however cannot warn you as its smugly located in its

hideout under the engine.There are no warning lights. A warning light

for oil is not very difficult to install as OE by bike and scooter

makers who have autolube systems fitted in their machines. It can save costly repairs and embarrassment to owners.

I am told that RX100's have run for about 120,000 to 140,000 kms without

the first engine overhaul.

In my bike, the two main crank bearings were minus any oil, the

crankshaft was dry and the engine nearly failing upon being oil starved.

All the engine overhaul parts and clutch were available with the

YASS.I preferred a new crankshaft assembly with the connecting rod (Rs

3500).I also preferred to buy a brand new oil pump (Rs

1647)though was advised against by my mechanic who suggested that I mix oil to petrol everytime there's a topping up.




Mr Rajabhau Bhole working on the bike in his workshop




The spares bills

Lately, the RX 100 had a nagging clutch adjustment problem since it underwent the engine repair job.As I was not using it much, only today the bike was checked. It was traced to a

missing small ball bearing that is located on the aft side of the clutch

connecting needle.This needle can be accessed by opening the left side

cover, which opens after the gear lever is dismantled.With the tiny ball

bearing not in its place , the clutch adjustment can turn into a


I also got a brand new Amaron battery fitted to the bike. The old one of

Exide make had been there since 2007 and was doddering.This new one has

cost me Rs 845=00 and after exchanging the old one, it was Rs 61

cheaper viz @ Rs 784=00.

So again, the RX 100 is back on its two wheels.I was not using it since

many weeks.

But today it has been made fully fit and will run on and on


anjan_c20072011-04-04 12:21:57

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Anjan as you have owned the Rx 100 for 20 years I believe you would have seen oil at the silencer end..? Common with two strokes if the reed valve gets damaged, the oil starts getting used up more than required and gets deposited outside. These are a few signs of a two stroke not in good health. I'm sure your 100 has run in since January, and you did a good thing by fixing a new oil pump as mixing oil-petrol is commonly done by two stroke owners, it is not at all recommended since the actual oil mixing work is handled by the dedicated pump. Good luck with your lady in red, and don't forget to rev her up !

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Thanks vr46 for your comment.I believe the oil pump stopped working about a week before the DDay but since I sparingly use this one, the fact did not catch my attention.In fact the engine was oil-starved.

True about the oil pump.I like it all original and such formulas do not suit me too, like adding the 2T to petrol and so on.

I am not exceeding 50 kmph now with the new engine parts and set-up trying to adjust in the 21 year old surroundings!

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