9 replies to this topic

[mini danny]

Hiya guys, just been stripping the clutch down to try find out why it's been slipping, found out the oil seal was leaking, but found this on the crank tail and on the flywheel, flywheel is only just a year old and is the mini spares ultralight flywheel, crank was all redone/reground same time as I brought flywheel , crank and flywheel where balanced together.

Engine has only been built a year and only done around 5k engine is producing 110/115bhp.

Is the flywheel/crank scrap ?

Dan

[Carlos W]

Is it verto or pre verto?

[mini danny]

Sorry forgot to add, she's pre verto

[Cooperman]

It looks as though it was not fully tight and has 'fretted' quite badly.

From the photos it sure doesn't look good.

[mini danny]

Flywheel was torqued and flywheel bolt was tight to undo, and flywheel was a Bugger to get off, but something Defo wasn't right, best course of action ? Crank tape and lap it in and hope for the best ?


Dan

[Cooperman]

Hard to say without seeing it close up. It's a bit of a 'judgement call' as a 110bhp+ engine will be revving at 6000+ rpm and any failure at those revs will be catastrophic.

I think a new flywheel would be sensible, but the crank may be OK if the new flywheel is lapped onto it. The crank could possibly be metal-sprayed and re-ground, but a replacement crank might be both cheaper & safer. Presumably it is all fully balanced and that would need doing again.

[mini danny]

Ok thanks, I shall try save them, if not I will order a new flywheels and hope the crank can be saved.

Thanks Dan

[Cooperman]

Keep your fingers crossed!

[GraemeC]

There looks to be some quite deep gauges on the crank near the primary gear. I'd hazard a guess some crap has got on there at reassembly and got trapped, stopping the flywheel mating properly with the crank. Although it has held tight (the crap acting as a key) it's still vibrated and fretted.
With care and attention you may save it, I'd certainly be trying. If not successful don't think you'd end with catastrophic failure, it may just fret worse next time.

[mini danny]

Ok thanks I shall see what happens, will keep you updated


Thanks Dan