Yamaha DT 125R 1994 project
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@Calum
Check out his pootube vid, then ask yourself why you asked
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Sorry, did I miss your dry humour?
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So basically i was just revving the hell of it for about 20 seconds went driving and felt weird. Engine stalled kickstart stuck.
So i opened the engine and there was bearing pieces over piston so rod bearing failure. There was sand in engine via bad air filter from previous owner. Also the piston was ridden about 1500km and the ring cap was 0,7mm on the top one and 0,5mm bottom one. And the needle bearing was shot. So the engine would have failed eventually. I think i know now what the werid side noise was.
https://i.imgur.com/jsw8S7K.jpg -
So basically i was just revving the hell of it for about 20 seconds went driving and felt weird. Engine stalled kickstart stuck.
So i opened the engine and there was bearing pieces over piston so rod bearing failure. There was sand in engine via bad air filter from previous owner. Also the piston was ridden about 1500km and the ring cap was 0,7mm on the top one and 0,5mm bottom one. And the needle bearing was shot. So the engine would have failed eventually. I think i know now what the werid side noise was.
https://i.imgur.com/jsw8S7K.jpg@jonne123 said in Yamaha DT 125R 1994 project:
So basically i was just revving the hell of it for about 20 seconds went driving and felt weird. Engine stalled kickstart stuck
Is called seizure by heat or lack of oil. Or screaming from cold start. Or all of the above...
“There was sand in engine via bad air filter from previous owner. “
Bad you never checked as well though bud (the filter) bike stuff 101
The rest is lost in translation, to me.
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Well it had rebuild top end and i changed the filter right away but didn´t realise that there was sand in the intake until month ago i cleaned it. Also the engine was making weird side noise probably from crankshaft. There was oil and mixture was rich.
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@jonne123
YouTube & your back tyre says otherwise!
An engine rebuild is always around the corner on a second hand bike, no matter what the previous owner says. If you do as good a job with the engine as you did with the rest of the bike, you’ll end up with a good, tight bike. Just run it in on less than 90% throttle!!
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Yeah... But it was like month after burnout. The engine has always made weird side noise. But it would really been sad if it happened during next summer. The bearing would failed. Also the needle bearing is totally worn and piston rings. Remember to clean your air filter!
But now plans for the project:
-Fix rust and paint some parts.
-Clean aluminium parts.
-Fix engine
-Replace worn parts.
-Sticker kit or wrap for plastic parts.
-Possible some tuning parts.
I´m open for suggestions!
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Yeah... But it was like month after burnout. The engine has always made weird side noise. But it would really been sad if it happened during next summer. The bearing would failed. Also the needle bearing is totally worn and piston rings. Remember to clean your air filter!
But now plans for the project:
-Fix rust and paint some parts.
-Clean aluminium parts.
-Fix engine
-Replace worn parts.
-Sticker kit or wrap for plastic parts.
-Possible some tuning parts.
I´m open for suggestions!
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I know that the crankshaft bearing failed. But there could be something else like a bearing.
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@jonne123 Yes, but WHY did the crank bearing fail?
There is no point in rebuilding it if you don't understand why it failed.
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Yeah the previous owner said it had engine rebuild but im guessing he meant top end because the engine bolts were so stuck and the engine was so dirty. Going to buy wössner piston and connecting rod. Good main bearings and seal.
@jonne123
Wossner and forged pistons are good, but you need to get the clearance right to allow for expansion. I understand buying the best you can, but is it really necessary? If you’re rolling in ca$h ignore me! Just don’t fall into the trap of thinking expensive is best... -
The cylinder is going to shop. And price isnt that bad and prox quality has sometimes up and downs. And i suppose they are better because they are made with strong material and theyre forged. The ktm guys here use wössner pistons. And i know that i need to let the engine warm really well and also idle after ride.
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The big end bearing you mean?
People probably overlook that as it's not something you can easily do at home as the crank needs balancing afterwards!
Pity. The Yamaha Con Rod kids don't come with the shaft either, so if you've nackered up the eye then you'd be looking at getting another crank.
Was it salvageable do you know?
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