Big end gone bang? Yes it has, NC35 engine Q's P3

[BillingCBR]

I'll see how it runs when I get it back together, gave it fresh oil and filter, so hoping that might help quieten it a bit, if it's just as bad I'll drop the engine, and just fit another working one, then strip mine down and see what's looking worse for wear. I'll be SO happy if I can get away with just bearing shells, although am expecting it might need a new crank AND new bearings

I'll do a full write up when I have more news.

[royster81]

I wouldn't be starting it again Sam, if it has spun a bearing best get it sorted now instead of wasting oil and potentially doing more damage.

Replacement motor is probably the cheapest cost effective way of getting back out there.

Good luck.

[BillingCBR]

Cheers Rhory,

Any idea HOW or WHY it could have spun a bearing? It won't make a difference now, but it could help me or others from coming to the same fate in the future.

I'm Lucky I bought that silly low miles RVF motor of Simon, I'll just swap over the single pickup on the '35 to the double '30 ones and use that until I either source another '30 or fix mine (not afraid to spend the cost of a replacement engine to keep mine going, like I said, might get away with a replacement crank and bearing set )

[Drunkn Munky]

Mate just put the RVF engine in and be done with it, ok you lose the long 1st gear and it isnt as pretty but at the end of the day its a better motor.

[BillingCBR]

Could do, seems a shame to put such a nice engine in my fairly grotty bike Is it really as simple as swapping over the pick ups and away you go? Wasn't sure if I'd have a problem with things like the CDI or rev counter not working is all.

[Cammo]

Could do, seems a shame to put such a nice engine in my fairly grotty bike Is it really as simple as swapping over the pick ups and away you go? Wasn't sure if I'd have a problem with things like the CDI or rev counter not working is all.

If you change the pickups you can keep using using all your nc30 gear.

[BillingCBR]

That's good news, as it looks like I now need to fit it in the bike :'(

The metal chips are in the sump, and there's a big bit of what I'm 100% sure is my piston skirt, so fucked big ends and a shot piston, great.

Sump as removed


The bit of piston next to a 10mm spanner (it has what appear to be machining marks on the other side)


The lovely remains of what I guess WERE my big ends


I can't tell you how gutted I am, truly devastated, was going great, and now this happens

[cbr400rrn]

Think that engine is now urm............. knackered.
At least you've got another engine to put in there mate, but what a flaming pain in the arse. What was the mileage on the engine before it turned on itself?
How/ why would this happen any idea?

[BillingCBR]

clocks said about 26k km before I changed for UK clocks 2k miles ago, so nearly 30k km. Next to nothing, as shown by 2 others I've seen in person (and ridden one of)

No idea why, but one of the banks was blowing oil, because it puffed blue out of one side (thats why I like the SP1 system, helps narrow the problems down a bit) plus the first part of the airbox was covered in oil, so have a feeling I had blow by on one piston, which was pressurising the crankcase and blowing oil out of the breather and into the airbox

[BillingCBR]

It's dead, piston is missing bits of the skirt, one half of the rod shell is ruined, it has chunks missing, the other half isn't damaged, its just completely missing!