Bike jumping/skipping in 2nd

Advice needed please...2nd gear, higher revs, half - full throttle - the bike jumps, like it's skipping a tooth. Chain and sprockets were brand new so what wear they have got is all together and chain is on the tighter side of the tolerance. I disconnected the QS to eliminate that as the culprit (bike still does it). Any ideas? Bent selector fork or missing tooth on 2nd gear? Doesn't do it in any other gear. Cbr1000rr-5

Any help here is appreciated, got 2 days at Snetterton on 23/24 and I'd love to have it sorted by then if I can

 

I've drained the oil and removed the filter (HF204), no chunks of metal stuck to the magnetic sump plug and nothing coming out in the oil either. I'll shine a light into the filter and see if I can see anything later but nothing so far.

Hopefully I'll get the clutch and gearbox removed later...I'll update as I go.

Still, if anyone has anything to suggest or has experienced anything like this before please help me out if you can

 

Cassette gearbox so you don't need to remove the engine.
Don't know why people think a tight chain is better than a slack chain. You end up putting pressure on the output shaft and bearing.

 

More than happy to run a slacker chain, the only reason it was on the tighter side of the tolerance was to see if the slacker chain was jumping a tooth.

So I've got the clutch and gearbox out. As far as I can see, there are no missing teeth, one of the forks has a fairly nasty score in it but all three of them are straight.

Going to give the gearbox to my local shop, rumour has it he's a ex BSB Honda mechanic so hopefully he can help me out

 

That was quick! How long did it take? Check the dogs on the cogs interlock properly.

 

It took me and a mate about 2 hours. We followed 2 YouTube videos one for the clutch removal and one for the gearbox.

I'll have another look tomorrow but everything looks as it should on first inspection.

 

Nothing worse than stripping it down and finding nothing, Well done so far, hopefully you or LBS will sort it

 

So, as my knowledge of gearboxes is zero. LBS said I need two new selector forks, and a new gear as the dogs are pretty worn.

I'm tempted to change the clutch while it's all out, the bike has done 43k and I don't know if/when it was last changed. Standard EBC replacement (src080) for a track bike or is the uprated clutch (srk080) a must? I can't afford a slipper clutch

 

I replaced my clutch at 40k miles, sounds sensible to me if you have it appart now, I couldn't comment on the best replacement option.

Hope it all goes back together as planned !

 

Replace mines original clutch at similar mileage with a honda clutch. I don't do track days but didn't consider it to be silly money for the life of it and I've seen aftermarket plates fall apart.
You can measure the plates as wash them in brake cleaner.

 

Ok so update......2 selector forks and a worn gear replaced (not 2nd) - 2 days at Snetterton and she's still jumping in 2nd. Me and the guy in the workshop hoped that changing the selector fork would be enough to stop it skipping. Gearbox will be coming out again and I'll be ordering another 2nd gear. Hopefully this fixes it

Snetterton also revealed I need to replace the radiator, but that's a separate issue. Engine temp hit 123 and filled my expansion bottle up, I was running pure water so hopefully a new radiator (it's damaged anyway) and engine ice/mo cool/water wetter will do the trick to keep it cool

 

Another update, 2nd gear and 6th gear replaced and the gearbox is now back in the bike waiting for the silicone to set on the clutch cover. I'll start her up on Monday. Hopefully I'll get a break in the weather and take her for a quick test ride but we'll see.

Got Brands Hatch at the end of the month and I can't stretch to replacing the rad at the moment so I've swapped the water out for Engine Ice. I run it in my SP1 and it keeps that lovely and cool so I'm hoping it'll do the same for the blade.

Fingers crossed this all works! If not then I'm scratching my head...unless I messed up the timing by a tooth when I did the valve clearances...

Here is a photo of 2nd gear, old and new. Some nice shiny rounded edges on the old one...

 

Ok...so yesterday was another session at Brands Hatch, interesting weather but........2nd gear didn't jump! FINALLY!!! so the rounded edges were causing or at least contributing to the problem. Very happy! Now to sort out the leak coming from the pipe running to the oil cooler or the oil cooler itself...