Rebuild failure

[barossi73]

Long shot but check the small end bearing is correct width.i was supplied a small end bearing that was 3mm too narrow with my last piston.luckily i noticed,and didnt fit,i tried to imagine the consequences...
At the very least it would be noisy,and at worst could 'walk' about from side to side,hard to say what might happen next but its not going to be good...

 

[Capz85]

Thanks I will check it next to the old bearing

 

[Capz85]

Got the cylinder back today, bolted it all back together........ And....... It seems to be back to normal goes smoothly into the upper revs and no more horrible knocking ( I hope I'm not speaking too soon).

I set the ring end gaps to 0.04,richend the carb and I decided to add base gaskets and set the exhaust port flush as this only gets ridden on the road I'm not chasing bottom end and yes I have a huge squish gap (2mm with std insert) but the whole time I've owned the bike I've ran it with 2.3mm on the old standard head and it's been very reliable so I'm ok with it but I also have the option to change to the higher comp insert if needed

Will take it out over the weekend and see how it goes, just happy to see some change for the better, and thanks for all the input and advice

 

[Jacob 'Berg]

Yes the cases were split and cleaned out



I've been to my local mx shop, they looked at the cylinder and think the piston is too tight, they also mentioned they have had a couple of cylinders done at the same company as me that came back with faults ..... They will re-hone this next week as its started to scuff and set piston gaps

Who did the plating work? Just curious.

 

[Capz85]

It was done by langcourt, but I don't think it was anything to do with the re plate although the guys at the mx shop said they have had a couple come back from there that weren't so great and they have honed it for me to put the cross hatch back and they said it was straight