Hi all, I posted a while earlier in regards to me running my KLX350SF till it locked up with the oil light coming on.

I'm going to get a chance to break into the motor soon and I was hoping someone with experience could talk me through what the easiest way to assess the damage on the motor is?

The top end is coming apart for sure, and I suspect the cams/journals are going to be toast. I am anticipating a fresh head for the motor. I think the cylinder will be fairly easy to inspect as well once the head is off.

I'm wondering what I will need to do to assess the bottom end of the motor? Is it as simple as checking to see if everything moves and there is no up/down play on the rod bearing?

Any help is appreciated please and thanks, I'm pretty new to all this, but I'm excited to learn.

 

Yeah, the cam bearing surfaces will be easy to diagnose. Once you get the cylinder off, you can get a better assessment of the condition of the rod/crank bearing. Obviously any grittiness, play, or total lack of rod rotation is going to be evident. If the rod "seems" OK in its play and rotation, rotate the crank to the rod position at the highest point so you can see the best view of crank/rod journal. If you see a bunch of blue to black discoloration...extreme heat...you're going to likely need a complete teardown even if the rod movement and play "seem" OK. I've seen some roller bearing cranksets hold up to some oil starvation situations because they don't need much oil and/or pressure to survive in most situations. However, they're not indestructible. Most scenarios we've seen with the KLX in a motor lockup due to no oil have resulted in a grenaded bottom end, so I'd expect the worst. We used to have a few more sources of services for rebuilding cranksets and such back in the day, but a lot of that has dried up. Most buy a replacement engine off the net and such.

 

Thanks for the reply. I was really hoping the bottom end was alright, but now I'm losing hope on that front

We'll see what I find, I'll keep you guys posted.

 

Don't lose hope. A lot of the low oil scenarios are just top end. No bearings for the cams means fast destruction when oil is sparce. The bottom end is a bit better off in that scenario.

However, You will soon find out that the top ends on the KLX are hard to come by, and expensive at that. Easy job to replace it though.

 

Well that helps give me a bit of hope. I saw a few heads for sale @ around 600 bucks shipped, beats paying for a full motor if everything else is still alright.

Here's to hoping!

 

Good news, I found a motor for 700 bucks and scooped it up. I'm going to be doing an engine swap

I'll keep you guys posted.

 

I think you'll come out ahead in the long run with that deal if the engine is in decent shape. Plus you'll have a bunch of extra parts to use or sell as needed. Good luck with getting it going again.