rs125 starting problems

[dardappa2004]

hi,im new to this and need some advice on my rs 125. basically i was riding around on my 03 reg rs 125 extrema for like 20 mins. And as i was spinning the bike around my hand slipped and revd the engine to 7000rpm for literally 2 seconds n then the engine died.(its restricted) and there is no compression now. i dont know wot have happened. any ideas?

[veze]

cud be your piston rings dude
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tlm50,mt5,sr50. rs125 extrema, cbr 400rr nc29 suzuki gs500e.Honda cbx250 rs . FJ1200 .fz6,fjr1300

[tutton]

Ye
Low compression reading &
Piston rings gone is related remember it happened to a car we had.
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Past: '05 Peugeot XPS '99 Aprillia RS125 '94 FZR600R
Current: '02 ZX636 A1P '51 CCM R30

[veze]

are you taking the piss?

'Ye
Low compression reading &
Piston rings gone is related remember it happened to a car we had.'

say something usefull if not dont say anything at all. its quite immature.

any way. it could be your piston rings , or it could be a gasket thats gone. take the barrell off and have a look if its scored. you may need a top end rebuild.
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tlm50,mt5,sr50. rs125 extrema, cbr 400rr nc29 suzuki gs500e.Honda cbx250 rs . FJ1200 .fz6,fjr1300

[dardappa2004]

thanks ill do that i bought the bike from a place called A N K MOTORCYCLES in coventry the bike was a day old and this happened, the bike was meant to be serviced etc. The guy claimed that i caused the engine problem by saying it was a cold seizure despite me riding the bike for like 20 mins beforehand . it cant be a cold seizure can it? and also claimed i was thrashing the bike even tho its restricted? i never took da bike over 60. . . .

thanks

[Kickstart]

Hi

It is possible to over rev an engine even when restricted. Quite possible that your hand slipping resulted in the revs going up higher than you thought.

Few details here on piston siezures.

https://www.danskkartingcenter.dk/html/piston_seizure.html

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[dardappa2004]

i only revved for like 2 seconds or so so cud it still be that?

thanks

[tutton]

[Kickstart]

[Timmeh]

[dardappa2004]

the engine had 2 bars on it on temp, the thermal reading goes up to 6??


thanks really appreciate the help

[Kickstart]

Hi

Cold seizure is from where the piston heats up far more rapidly that the surrounding barrel. Rev the knackers off the engine for even a couple of seconds (at 10000rpm the engine has had over 300 combustion cycles in 2 seconds). The piston is basically cooled by the incoming fuel and air (with the spark plug heat range having a large effect) and has little to do with the water temperature that the gauge is reporting.

I am not saying it is a cold seizure (suspect it is unlikely), just saying it is not impossible.

What is needed is a good look at a piston by an independent engineer.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[dardappa2004]

well guys i have bought a brand new top end i have fitted it, the owner before had ragged the bike senseless . . . typical i no and on top of that it turns out that they had mixed 2stroke bike oil with engine oil. . so not got clean the jet. Is th normal for the piston to move up and down the barrel easy without oil? cause that what the old piston does also the top of the piston was completely carbonised and the head was warped blue from the coolant?

thanks

[Kickstart]

Hi

The blue staining of the head is not unusual

The piston will move up and down the barrel easily without any rings on it.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[dardappa2004]

it had the ring on? is that normal for it to easily slide up and down woth no oil and piston rongs on?

[Kickstart]

Hi

Would depend on what you mean by easy. I would expect it to stay in place if you held it vertically, but you would be able to push it easily.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing