12 450F is fubar, after scavenge screen cleaning...

Don't know what the &%$#@! I did wrong, other than maybe not getting the flywheel torques proper.  I used motion pro puller, got flywheel off, took bolts off scavenge pump cover and chain guide, took out stupid little screen and cleaned it.  Bike is right at 15 or so hours.  Wasn't too bad.  Re-assembled according to service manual, with white dot facing up and outside towards magneto.  Lubed the roter and shaft of the scavenge pump, put it back in with all the way.  Only question there was where do the rotors line up, but figured it was a non issue as long as they are grabbing.  Put flywheel back on and used a strap wrench to hold it while I went at it with rachet and rubber mallet.  Couldn't hold the bitch very well without losing the battle and rotating the engine.  Each time I moved the crank one way, I would reset to original position, and give her another whack.  Had about 3-4 threads exposed past flywheel nut, figured it was good to go.  Put magneto cover back on, added oil and new filter, proper oriented yes.  Thing is, I added a quart and there was zero window presence even after tilting the back.  Had my 5 year old in on this part, and let him continue to fill, to which I turned my head for a moment, and he had half of another quart in before I could catch him.  But still nothing in the window.  Said &%$#@! it, went for a start.  Well she fired up, but made an unfamiliar sound, almost a high whined gurgle, and immediately fire hose puked Castrol 4T right out of over fill, not a little, but a good half quart.  And she sounded like crap.  In fact, she didn't act cold with the choke out, didn't rpm up to warm like normal.  Blipped throttle and she died. Ok.  Back on the stand.  Added a little more oil, and she started showing in sight glass.  Good to go.  Took off stand, fired her up, and she did same thing.  Projectile vomitted another bunch of 4T on the ground.  I'm pissed at this point.  

 

So off she went to my local Kawi mechanic.  Get there and got my wrench head to watch, kicked her over, and she puked more on the ground.  Ok, so what the hell did I do wrong?  I'm figuring flywheel is the culprit.  Any good guesses would be appreciated. Next time, I'm leaving that screen dirty.  To hell with it.

 

/Jeremy

 

 

Only question there was where do the rotors line up, but figured it was a non issue as long as they are grabbing.  

 

 

Are you asking about the woodruff key in the crankshaft? It lines everything up.

Edited by duhameister

Probably talking about the oil pump "rotors" or pump under the cover over screen. Sounds like the oil pump is not working.

or way too full of oil

Woodruff key is for the flywheel.  I'm talking about the rotor on the scavenge pump itself.  Looks like a star with a shaft that fits into corresponding star pattern.  It's not watt to full of oil now, let me tell ya, it was coming out like a fire hose.  Yeah, the service manual isn

t exactly clear about how it lines up, err, which is a start position when putting it back in.  Don't see how it wasn't a problem prior to me popping it out, but never know, I could have jacked it up.

i did mine on my 12 and didn't remove anything that wasn't necessary... didn't even drain the oil.  Only issue I initially had was that one of the small dowels from the pump cover fell into a puddle of oil in case and I didn't see it, and cldnt get the pump cover to seat... but im a mechanik by trade so pulled it off to see what the hell, and found the dowel.

 

Put it all back together and fired right up. probably gonna change the oil this week after that project and 2 races  since I did it last.

 

 Probably overfilled it, im guessing. there is a lot going on in that case.. and if you figure that the motor only holds a quart to begin with, then 25% over filled is HUGE.....

Bike holds a tad over a quart. Sounds like you put 1 1/2 to 2 qts in. Way to much!!!!!

Well yeah, that's assumed since I lost the moment with my little monkey pouring away.  But once it was all spit out on the ground, it's still acting funky.

Ok, I'm thinking, and follow me here, how is it possible for so much oil to get pushed out of the overflow unless the scavenge pump is not working?  Seems like the oil is just making it to that side and that side only, thus getting pushed out.

or way too full of oil

Or scavenge is not scavenging it to other side?  Wonder why though, since I put that little pos back together correctly.  

See, when I pulled the scavenge pump cover off the rotor and shaft came with it, and the cotter pin fell out that holds inner rotor onto shaft.  I put it back in, but maybe it didn't sit right.  So shaft would be spinning but no rotor action to scavenge the oil.  However, this would imply it's not on at all because if inner rotor sits on it, as in pin is not in slot on back of rotor, it would be impossible to get the cover back on....feel like I may just go pick that bitch up and tear into it again...or just bite the bullet and pay for a mechanic...

well, the pump still has a limited capacity,,, you cant feed it more than it can (theoretically) swallow. if it cant consume what your feeding it, then there is gonna be overflow.  If its so overfull that the internals are foaming the oil, then the pump is volumetrically less efficient, since pumping air doesn't pay the bills.   take it apart, pull the plug and slowly turn the motor over to see if the pump is turning w/o the cover on... you know in your mind what you think might be going on, SOOOO.... make a flowchart on paper, and make the motor do what you want it to do... as a wise old man once told me 30 years ago...... its a piece of metal, its not smarter than you.

This maintenance is really easy and I can only say this because I learned the hard way.  I fubar’d my 09 when I first tired.  My main problem was I didn’t realize there were so many dowls, pins, and notched parts involved with this maintenance.  Look at the OEM diagram a few times.

 

Make sure you have all the parts accounted for.  I recommend laying the bike on it’s side vs. working on a stand.  There are a few dowls on the oil pump cover.  Make sure you know where they are.  There is a small key\shim that holds the flywheel in place.  For a long time, I thought I was putting it in wrong.  But I think there is only way one it can go in.

 

The shaft that sits under the oil pump cover has a notch at the end.  When I pulled the cover off, the propeller pulled out a bit and didn’t go back in correctly.  I didn’t realize this when I reassembled!  And you can imagine where this is headed…  I should have noticed this because the oil pump cover didn’t sit flush when I tightened down the bolts.  I found out when I started the engine.  I had oil pouring out the overflow tube.  I also heard a loud, very bad noise in the engine, when the propeller broke.  

 

As far as getting the flywheel off on.  I use an impact wrench feed by the air compressor.  Nut comes right off and when reinstalling, never worried about a strap wrench.

 

In this picture, you can see the propeller spun on the cover.

 

IMG_0206.jpg

 

Good luck.

Edited by Mike OBrien

Well I'll up you one.  Got the call today.  Turns out the cotter pin that holds the inner rotor onto the shaft wasn't in or fell out a little.  It gouged the rear of the case, right where rotor would sit/touch the case.  Looks like it got pressed in somehow, and can't figure out how as the 4 bolts for the scavenge cover are only 87 inch pounds.  The cover was flush, to best of my knowledge and the rabbit ears were engaged with shaft of primary oil feed.  Think where I messed it up is not using crease on the cotter pin to make sure the rotor doesn't slightly pop out.  The cotter was bent a little on one end, and where it sits in the slot on back of rotor, it also gouged it a little.  Also, the shaft is pretty stuck as in you can't pull it out by hand, so maybe the real culprit here is how the shaft was sitting.  I did hear a high pitched whine, then the oil puked.  Mechanic says I need a new case(s), as oil pressure will never be right and it will suck air.  Any truth to this?  Had him pump his brakes and give me an estimate before a tear down.  If this is true, think I may say to heck with it and just pick up an entire new engine, and play with this one.

 

The gouged area in the case, if you look into the empty space when scavenge pump shaft, inner and outer rotor is out, is kind of like a crossbar.  On this crossbar you can see and ident where the cotter pin dug into it.  It's not severed or anything, but stainless steel wins versus aluminum I suppose.  FWIW, I did this with bike on stand.  So maybe it slid out while I was putting the cover back on.  Also, there is a little galling on inside of the cover, like in your picture, just not as bad.  

There's a lot of old threads on this topic and a lot of posts that warn the same two things. The warnings are:

 

1. not letting the cover dowels fall into the motor. Just being aware of them and having the bike upright helps.

2. ensuring that the cotter pin on the pump rotor is seated correctly or better still the rotor is not moved at all.

 

Getting either of those things wrong and it's crunch or snap.

 

My guess is that most of the time people clean the screen and it wasn't necessary.

 

I wouldn't be hammering the flywheel either. Magnets don't like that.

So c'mon bro's, need some input.  Do I drop the dime on this and slap in a JE 13.5.1 piston, or pick it up and order the parts I think will remedy it.  However, here are the knowns:

 

1.  That stupid pin did scar the case, not the inside diameter, rather the wall on back side of inner scavenge rotor and left a pin shaped dent in the aluminum.  

2.  The scavenge shaft, when I looked at it with mechanic, would not pull out under normal hand strength, which implies more could be wrong on primary feed shaft side. Like maybe the dog ears of scavenge shaft snapped and wedged itself.

 

Input is appreciated guys.  would hate to commit such resources to something the can be remedied easily.  However, according to everyone the case is scarred enough to be a problem down the road.  Arguments are the the notch in the case can cause that roll pin to fall out.  I agree, but does the inner rotor ride on the case wall?  And doesn't the rotor act as a paddle of sorts just picking up the oil and transferring it back to the other sid?

This maintenance is really easy and I can only say this because I learned the hard way.  I fubar’d my 09 when I first tired.  My main problem was I didn’t realize there were so many dowls, pins, and notched parts involved with this maintenance.  Look at the OEM diagram a few times.

 

Make sure you have all the parts accounted for.  I recommend laying the bike on it’s side vs. working on a stand.  There are a few dowls on the oil pump cover.  Make sure you know where they are.  There is a small key\shim that holds the flywheel in place.  For a long time, I thought I was putting it in wrong.  But I think there is only way one it can go in.

 

The shaft that sits under the oil pump cover has a notch at the end.  When I pulled the cover off, the propeller pulled out a bit and didn’t go back in correctly.  I didn’t realize this when I reassembled!  And you can imagine where this is headed…  I should have noticed this because the oil pump cover didn’t sit flush when I tightened down the bolts.  I found out when I started the engine.  I had oil pouring out the overflow tube.  I also heard a loud, very bad noise in the engine, when the propeller broke.  

 

As far as getting the flywheel off on.  I use an impact wrench feed by the air compressor.  Nut comes right off and when reinstalling, never worried about a strap wrench.

 

In this picture, you can see the propeller spun on the cover.

 

IMG_0206.jpg

 

Good luck.

 

So what was the remedy in your case, replace the cover and rotor?  Any case damage?

When I have cleaned mine, I held down on the end of the oil pump shaft through the hole in the cover. This keeps things in place when you lift the oil pump cover off to get to the screen. My first KX450F was an 07 and it had a lot of crap in it when I first cleaned it. I have since had an 11,12, and 13 and it has seemed like a waste of time when I pulled the screen out because it had very little debris on it. I checked the 13 when it had about 15 hours on it and it was clean. I won't check it again unless I'm in there for something.

Edited by mx317

Okay, anyone think I'm crazy for getting talked into basically a full engine rebuild, new cases because of such a small indention?

Okay, anyone think I'm crazy for getting talked into basically a full engine rebuild, new cases because of such a small indention?

 

I probably would have tried to do it my self... The service manual pretty much shows you how to do anything to these bikes.... But if you don't have the time to mess with it, you have to pay a lot more...

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