First off sorry if i post this in the wrong section or if this has been covered before. I have tried googling my problem with no luck.

I have a 2009 klx250sf that has about 30k miles on it. It has snorkel removed, jetted and slip on. And it was running great. I have done all maintenance on it myself. Oil changes, valve clearances, air filter, spark plugs, tires, ect. And always properly torquing everything.

About 1500 miles ago i pulled the trigger on the 351 bill blue big bore kit and installed it myself. Following the instructions i could find and torquing everything to what the manual said to. And doing the proper break-in for the new 351.

I've had some problems trying to get the carb jetted properly. (at idle it would run great when cold but once engine got hot it would idle low and would almost stall) The engine felt good in the beginning and i took it into a dealership shop to have someone look at the carb problem and while they had it, they said they did a compression test(a few weeks ago) and it came back good. I got it back from them to try to figure out the carb problem myself cause they were taking a long time and charging an arm and a leg that i can't afford right now.

But now i have an even bigger problem and not sure what to do. It looks like a bearing inside the crankcase has started to come out of the crankcase(from looking at diagrams, its what it looks like to me) I could be totally wrong. Engine still runs good (alil more noisy than before) . It spits oil outta the hole when engine is running.

picture of where it is
https://www.dropbox.com/s/xuixi7qk7u...49-07.png?dl=0

Picture of hole
https://www.dropbox.com/s/e7vt9f5qjs...71034.jpg?dl=0

picture of diagram and bearing i think
https://www.dropbox.com/s/txshsk6wfm...24-08.png?dl=0


My questions are:

Is my crankcase shot?
Do i need to replace it all ( I'm not sure if this is even worth it)

Can i just replace the bearing?
And just JB weld the hole closed?
What could cause this to happen?
Do you think this still would have happened if i wouldnt have put the 351 kit on?

i don't mined getting my hands dirty but this seems like a major job? Should i leave it to an expert or is this something i should be able to tackle(again not sure if its worth it to take it to an expert)?

Sorry if i missed anything. And thanks for any advice

 

Ding, ding, ding, we have a new, problem!
I think that bearing is associated with the balancer. The 351 kit shouldn't make any difference. You'll have to pull the engine and split the cases to see what damage there is in the case where the bearing sits.

Ride on
Brewster

 

That is just a crazy thing. It doesn't look like a loose bearing would cause that, that bearing is alot bigger than that hole. Was there a gremlin in there with a .44?

I would be tempted to just clean it up and plaster it with JB weld. I don't think you could tap it and put a screw in it cause the bearing is probably just right there.

Maybe a casting defect finally appearing?

 

Well when looking at it in person it looks to be a ball from the bearing that is causing the hole. And when i touch it with a screw driver or whatever i have that will fit in there. I can poke it and it will slightly move in all directions . Which i believe would mean the hole bearing is shot. I did think about patching it and just running it till it dies. But the more i think about that. It seems like there are better choices or options.

I think i might half to crack the case and do some digging. Definitely didn't want to. Cause i feel unqualified to take this job on. But i guess its already broke. So how much more damage can i do.

but please keep me informed with any advice, ideas or information that might help. I need as much as i can get.

Thanks

 

To me it looks like the hole could have been caused by something from the outside hitting the case possibly from the front tire. It looks like a shot from a gun hitting soft metal causing a crater effect. If that is the case I'd try to do the JB Weld thing and see if it holds up.

 

Well, the ***** in the bearings are in the races, the race would be pressed into the case. It would be virtually impossible for a ball to escape through the race. Google a bearing and look how the races completely enclose the bearings. They may be able to escape, but it would be down the axis of the shaft.
What you are hitting with the screwdriver sounds completely bazar.

 

I will try and take a better picture on monday of the object i am seeing. But with what i can find, it looks and seems like a ball bearing is what I'm looking at. I could be totally wrong. And agree it does seem bizarre. whatever it is it seems like it is coming from inside out. The metal crankcase where the hole is mushrooming outwards and not inward.

 

Strange issue.
I would use a stethoscope to listen to the bearings on each end of the balance shaft. That will give you a better idea if that's an issue. I would definitely go the epoxy route if it's a casting problem-You have to split the cases to change those bearings.

 

After taking a closer look at the pic I'd say that's a casting defect. Clean any paint and oil from the area and use epoxy to full the void-problem solved.

 

Looking at a pic like this on the internet makes it tough to make a decent call on what the problem is. OP, on your assessment that this problem is coming from the inside of the engine because of the way the hole appears, I'm not sure what I'm seeing in the pic verifies that absolutely.

The crater in the aluminum going from small to large as it exits the case is also how an impact crater from the outside could appear...kind of like a "pock mark" from a bullet striking a brick wall.

I'd think pressure from an internal failure like a bearing shelling out would do more damage resulting in visible crack(s) at the point of impact within. Yes, connecting rods will often poke a clean hole in an engine case/block, but that hole is usually catastrophic and obvious. I'm leaning toward an external strike for the moment.

Here's what I'd do. You indicate that the engine was still running. Clean that area with brake cleaner and apply some JB Weld or other appropriate epoxy repair to keep the oil retained. Run the engine. If there's a bearing shelled or something else catastrophic going on, you're going to hear some nasty noises, and your problem will indicate an engine case tear down.

Still, your description of something appearing to be "loose" or floating around at that hole that you can manipulate with a screwdriver is definitely concerning. However, there may be a gear or chain at this location, if as Brewster states, where the balancer system is located here. I haven't taken the time to study the balancer system location in our KLX, so I'm just throwing that out there. The KLR600/650 in rare instances had some catastrophic problems with tensioner chain slack in the balancer, but that probably doesn't apply here.