Bottom end bearings. I'd replace them NOW before you spin one and need a crank/head/valves/oil pump. It's a bit expensive to have them done but it's 1/2 the price of repairing the motor after the fact. Gives you an excuse to have the crank lightened too

 

Yup. "Badness has occurred." Pull it apart now, before it does more damage.

If you find out that a rod bearing has gone bad (which is likely), measure the journal and the affected rod very carefully for out-of-round or out-of-tolerance.

 

Shit, I was hoping something from gerbox area. Did not know crank/conrod bearing produce copper color.

 

only place it comes from.

 

Crank main or rod bearings are the only 2 places for them to come from.
Do loke what was said earlier and pull the crank now or you will trash the motor.

 

Thank you for info. Will split the crankcase next week.

 

What everyone else said. Not good and looking at a big repair bill. Crank will need repair or replacement if the bearings are starting to shred. I'm just getting my crank back and will be starting the rebuild soon. It sucks.

 

Wow, how many miles on that?

 

7000 street miles from previous owner. Plus I did one race season on it.

Oil and OEM filter had ca. 1000 miles. Motul 300V Factoryline (Ester core)
Is it too many miles for race track use?

 

Should've used amsoil lol. I'm seriously joking.

 

my 2004 is 65 000 KM and im racing the sh*t out of it

 

Will keep in mind to change oil every 300..500km.
What are other common rookie mistakes?
Probably it's good point to put in kit bushings as I'm having headwork too?

 

Kit bearings are no longer available unfortunately.

Every 300km of track miles should be the limit. I don't measure by mielage. Every track day or every race weekend, whichever comes first.

 

Not right and use amsoil. 1000 miles is nothing on oil. 7k miles on a g4 engine is nothing. My first thought is that prior owner did something stupid.

 

Track riding is different then looping. Even superstars that use amsoil in their race bikes change it just as often. With an amsoil filter of course.

 

The severe loading in the transmission will shear the oil to a lower viscosity, too. And if your engine is running on the rich side, you are going to get some fuel dilution. I don't think 300V is meant to be used with long drain intervals at the best of conditions.

 

Here some results after engine disassembly.
Big end bearing of 3. cylinder did turn, grinding ca. 0.8mm gap.
Obviously rod is toasted, big end hore is 0.3mm out of round.

Crank you see on the picture has bearing material on it on one spot, but it's not as bad as it looks. Did very minor polish with 3000 grit just to take soft trasfered material away. Have not measured it jet, but looks almost no damage.

Crankshaft bearings (picture) is in very good shape, will plastigauge them, possibly no need to replace them, what do you think?

Oil pump still turns, but has copper pieces pressed into surface, gets replaced.

Next up I will measure everything carefully.

Members please post tips-tricks about crank repair.

Lession from my story: If you hear even little metal pounding noise, then take off oil pan or oil pump to check for deposits.

 

Replace all the bearings. You're in there now. Trying to save a couple hundred on parts is usually the quickest way to redoing what you've already done.

 

Dricked, you suggested to lighten the crankshaft earlier. Can you feel or how much subjective improvement do you feel in terms of flickablity and faster revving? Was it definitely worth it?

 

I didn't do this on my zx10 and I wish I did. On my 2008 GSXR we removed the counter balancer and installed a dummy shaft. It revved very quickly after but the bike did have slightly more vibration. It was a very noticeable difference. It may not be a great mod for a street bike because of the added vibration.

 

I have no experience with Gen4 crank but all other Gens i have had lightened, edged & balanced cranks yes much smother spin up & noticeably less vibration at bars, if its out then pay your money it is noticeable :wink2:

 

that crank bearing journal is going to require professional repair. also strongly suggest u have other rods ck'd for roundness and resized if needed.

 

I'm in the middle of this exact project. Subbed for when I can type a novel later on a real keyboard.

 

So, I'll give you a quick update on where I'm at with this. I spun the #1 rod bearing back in Sept. Rod journal was trashed. Sent it to APE out in California for repair and upgrades. Just got it back in my hands last week. Yes, it took them from Sept to Now to get it repaired for me due to their back log. That's the only shitty part of the deal because it looks like they did an awesome job on the repair.

It's a big expensive job for you to undertake. The crank was repaired, lightened, knife-edged, nitrided, and straightened. It was also balanced to 14,000rpm and the rod oil supply holes were fluted to supply more oil to it. All of this work cost Just over $1,000 (new crank is $960). That cost also included new rod bearings and them matching them to the crank and installing them in my rods BTW.

As for the other stuff. Your oil pump is trashed. Throw it out. Your oil pressure relief valve is also trashed. New one there to. I tried to just get away with one new rod, but all of the other 3 were out of round due to the heat from losing the #1. All new rods. The main bearings looked OK, and after having plastigaged the crank yesterday, all of the main bearings are out of spec. The service limit is 0.60mm and I got 0.51mm across all of them. Standard is 0.10-0.34mm. No two ways about it, mains got to get replaced. The good news is they are all consistent and the crank journals are all in spec as well.

So, you've likely got similar issues. You're going to need a set of rods, all new bearings, new or repaired crank, new oil pump, new oil pressure valve, new oil pickup screen, and all new gaskets at a minimum. You're going to have to clean and reclean the entire block and all the oil passage ways. Hopefully I'll have mine running again within a couple of weeks. Total so far on this repair bill will be just shy of $2,000. It sucks, I know. Good luck to you!

 

My '11 blew the no. 4 crank bearing according to Fremont Dealer. This g4 had 50,000 miles of twists and went strong right to failure. At 170 in 4th on short straight, upon failure, sounded like an ar-15 going off nearby. I immediately noticed loss of power but the bike did try to respond to throttle, yet I knew right away the bike wont' make it home. Stopped and the right side down low was so hot that the grey foam padding was on fire. Flames. I at first thought back away as flames were big, but when I studied, flames were only a few inches and mostly smoke. I had gloves on so just pulled that foam out and all cooled.

I report the above to offer a difference between our two experiences. I never tracked this bike but I beat the crap outta it far more than any track bike, week after week four hours per loop, 1.5 hours hard.

 

Welcome to club Scout! How many miles did you do from last oil change? What do you think was the root cause?

 

failed parts not strong enough. I rarely change the oil. I use amsoil 0 I bet you had fresh oil What's your fail theory?

 

Skydork, thanks for good post. How much was your crank bent (you said it was straigtened)? Did measure my crank and it is 0.15mm amplitude measured on middle journal, needs straightening too.

Would you post a picture from lightened crank, intresting to see from where material was taken off. I will have chat with crank guru next week.

 

The crank isn't bent from the spun bearing. It gets bent from the repair work. They have to weld it up and then grind it down. That warps it, so it gets straightened. Then it gets bent again from the machining to lighten it and gets straightened again. It gets straightened several times during the repair process.

 

Fluted rod journals....

 

Radical surgery. Hope it will handle like 600 from reduced gyro effect...jealous.

 

It's really not that much weight in the grand scheme. Less than a pound. It will spin up quicker and May handle a tad better, we'll see. I'm more concerned with the improvements to the oil distribution to stop this from ever happening again.

The fluted rod ends will help. I also shimmed the new oil pressure relief and got a thin head gasket from the race kit. The head gasket has a reduced oil passage way which will keep the oil pressure up for the crash and cams.

If interested, I can post my parts list.