Conrod side play, big end gone?

[Symon]

Hi, my wife's electra x started making a distrubing distinctive tat tat tat tat noise especially under load while at the Isle of Man GP last week. It had a distinctive ring to as well which made me think it was cylinder head or barrel related. Anyway stripped off rocker covers, tappet cover and finally the head and barrel. The piston is very heavily burnt on both sides were the gudgeon pin goes thru and underneath. Checked the rings in the bore and although the gaps are bigger than the manual says for new, not quite to the limit.
Putting the pin back into the piston just before it engages in the hole on the other side using a tourch i can see that its touching on 1 side but a gap on the other so the piston has had it.
Now to the crank, i'm coming to the conclusion its busted, the conrod will rock from side to side by a 3 or 4mm. Not slide side to side in line with the shafts of the crank but in the center upright position it will rock so many degrees left and right if that makes sense.
Should there be any movement from vertical side to side, considering taking tomorrow off and riding a couple of hundred miles to Hitchcocks here in the UK to look at a new crank.

[Ice]

Hello Symon and welcome aboard.

 3-4 mm sounds a bit much  for a roller crank to me but then someone versed in AVL would know better than myself.

Sorry to hear of the problem. I hope you can get it resolved satisfactorily.

 You might seek the advise of forum brothers Bullet Whisperer and Chasfield, they are pretty sharp fellows and U.K. based as well.

[anadikaal]

yes, 3mm is too much.  the crank needs to be repaired. best, get the H re-enforced connecting rod/pin with the inner race.  expensive, but it will last.