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.

 

Wow, that's an interesting one. No suggestions other than start a new thread and re-post this in the KLX250 area here:

https://www.kawasakiforums.com/forum/klx-250s-71/

 

Thanks
Just re-posted to the klx250 section.

 

The guard is in the way, but worth noting. Why would you suspect the bearing?

2010 Kawasaki KLX250SF (KLX250WAF) Engine Cover(s) | Cheap Cycle Parts
Shows that there is a relief valve

I have not worked on one of these engines yet. Good luck I would be curious to know exactly where the oil leak is coming from before guessing too much here.