Ruby succumbs to seizure.

[motormike]

Today, Ruby gave her very life for the team.
After 21 & 1/2 continuous hours of extreme hard running, she slowly seized and rolled to a quiet death.
Most likely, a crank bearing has failed causing the premature failure.
My 6-man team was competing in a 24-hour endurance challenge sponsored
by the local vintage group known as "Pseudomoto", of which I am a charter member.
We finished in 3rd place behind a 1965 C200 Honda frame powered by a Lifan 125cc.
Our total mileage was 973.4, losing to the winning 997....only 24 miles more.
If she had lasted another 2 & 1/2 hours, we would have easily won.
Mostly, I am proud that she was the only 2-stroke in a field of 9 bikes to enter.
Good night, sweet princess...

[Wheelman-111]

Greetings:

Sorry, Ruby. Should be fixable?

[scootfast]

It's a humbling greatfull death that will teach you and the rest of us a lesson. Let us know what went wrong. It's how we learn. Sorry bro.

[dun rite]

sorry for your loss MM. You going to try and put her back together?

[1man8scoots]

I've heard cr125 pistons fit them a while back. I don't know for sure if they do or what year but if so you can over bore and do a little port work. Are bottom end bearings available?

[motormike]

Thanks all...
I have a second complete scooter that was said to have "ran when parked"...
I planned to sell Ruby, again, after completing the 24 hour challenge.
Only makes sense to swap the parts engine into Ruby and hope for a runner to sell.
Finding out WHY it seized may not be very practical for me...after all, she had just ran for 21 and 1/2 hours.
Seizure was truthfully expected before then.
Several projects lurking about the garage demanding priority over this autopsy.
Of course I will share the findings if ever discovered.
Heard the same about CR125 pistons working.
Love this forum...rock-on...

[Wheelman-111]

Greetings:

HuH? You're gonna pull the engine out of Ruby anyway, right? Why not dismantle the seized one after the parts bike engine is safely installed? We're all itchin' ta know! Pump failure? Tell me ya didn't run the oil tank dry...

[motormike]

Greetings:

HuH? You're gonna pull the engine out of Ruby anyway, right? Why not dismantle the seized one after the parts bike engine is safely installed? We're all itchin' ta know! Pump failure? Tell me ya didn't run the oil tank dry...

You're right Wheelie...it wont take very long to pull it apart.
The pump may have failed, but how will I know that ?
The tank was kept full regularly, and the pump was really pushing the oil through it at generous rate.
She consumed more than two quarts in 973 miles, maybe closer to 3 quarts.
One interesting note : midway through, I was forced to switch to Lucas semi-synth after the first two quarts of Motul was used up and availability was nil. Could have been a factor, but it really shouldn't have been...

[patthesoundguy]

So sorry about the motor mishap. Hopefully the spare motor works to get a good return on the scooter. At least it was for a good cause that it croaked

[motormike]

Again I ask, How will I know if the pump stopped pumping ?

[1man8scoots]

Remove the pump and spin it. Check for any axial play.

[ped]

hi Mike. remove the pump attach a drill to the tip make sure you're spinning it the correct way.

Bore the cylinder head out ,put the bigger piston. grind the gears off the pump reinstall. premix 32 to 1.

[Johnniespeed]

CR125 pistons have the ring stop dowels in the wrong place, the ring end gaps will go through the port, not good. Been there didn't do that, resold the CR 125 piston/rings.
If you could relocate the stop pins, you may have a chance on getting the piston to work.
I maintain my opinion that the pumps don't stop pumping oil and do not fail. But I do maintain the opinion that the cylinder walls get hot spots during extended strained use, and gall the piston/rings.
I also believe that the hot spot issue on air cooled engines, is a major reason that most everyone went to liquid cooling, since the water jacket can absorb and disperse temperature variations, thus prolonging engine/piston life.

[paulpauly7]

if the pump had failed and you were only running fuel the spark plug colour would look kinda like rust so would the inside of the head the top of the piston and exhaust port .

[ped]

No my friend this is a 1984 125 aero, one year only. nothing's plug and play. you have to make it work. check online or with your local MC shops. a oversize piston maybe, or weisco piston? a machine shop may be able to move those pins?

I had my oil pump fail on one of my elite 50. had to rebuild the motor.
Yes the cylinders do get hot.

hopefully Mike will be able to get his Ruby going.