Blew it up after 64,000mi, time to rebuild
 

So I blew up my motor last August. I thought I had a slight case of piston slap, what I really had was rod knock.
Come to discover you can't buy a rod, you have to buy the whole crank assembly for $500.
So it's time to split cases.
The shift shaft assembly is the last thing to remove before I start pulling case bolts. It was late last night when I got to that point and called it a night.
Once the cases are split and the crank is removed, I'll be ready to start putting it back together. I'm going to replace all the bearings. Probably not necessary but with 64,000mi on the bike and it totally torn down it seems dumb not to do it. It would suck to rebuild and later have something I didn't replace cause a failure.
The frame has some issues as well...
I rode the poor beast 12mo/yr for 3 years in northern NH through snow, salt, and sand. I washed it every week, but that just wasn't enough. In the one spot that I could never really see or clean I have a whole in the frame (surprise, surprise) about 1/2" wide and 2" long. At least now I have a real reason to buy a welding set-up.
I'll try and post some photos once the cases are split and I'm putting things back together. I hope I took enough pictures and made enough notes.

Here she is broken down enough to get in the car.

https://cimg4.ibsrv.net/gimg/www.kaw...0d4a102c3a.jpg

And in the same state unloaded at my friends garage.

https://cimg5.ibsrv.net/gimg/www.kaw...1ed260dc7a.jpg

And finally broken down after 8hrs of work.
https://cimg0.ibsrv.net/gimg/www.kaw...2ae9e77b46.jpg

And a pile of parts.

https://cimg8.ibsrv.net/gimg/www.kaw...6844dae797.jpg

The whole lot got thrown back in the car and taken down into my basement workshop to be cleaned and reassembled.

https://cimg2.ibsrv.net/gimg/www.kaw...59fc4c52b8.jpg

Keep us posted!

Looking forward to following this one, take lots of pictures!

Have you compared the repair costs and resale value vs buying a new KLX250?
There also is the risk of the rebuilt engine failing vs a new bike warranty.
Did you come up with numbers? What were they?
Not being a jerk, I am curious and too lazy to do an analysis since my bike is OK,
but if/when my bike grenades I will have some knowledge from your experience.

@snappster - First, my thought is that there is no resale value in my bike as a whole (and working bike); too many miles and scars. A new KLX is out for me for a few reasons, but mostly because if I got a new bike it would be a 450 of some type.
I'm not too worried about a rebuilt engine. Now I'm no mechanic but I do have a torque wrench, skills, can follow directions, and when needed, help from a real mechanic.
I'm finally going for the BB big bore now that I need a new piston and jug.
Still trying to find someone to rebuild the crank I have. Hopefully that will be less than 1/2 the cost of a new crank. If I do need to buy a new crank then so be it.
I didn't really do the numbers but a rough guess is that it will cost the same or less as a used bike. Since I'm doing most of the work the cost to rebuild is time, which I've got. And I feel like I owe the little KLX for all she's done for me and want to do the full rebuild just for my own experience and hopefully satisfaction(once it's working again).

So for the numbers I know about:
Crank - $476 new, rebuilt unknown cost
Bill Blue BB - $533.95

And the numbers I don't know about:
Bill Blue head port and polish - $???
Gaskets - ~$200 it's a guess, I need all of them but two I already have and those that come with the big bore
Bearings - ain't gonna be cheap buying Kawi parts but sourcing them from a bearing company might not be so bad
Seals - shift shaft, water pump seals, drive shaft, kick start
Air box boot and the piece between the carb and engine
I might try and make a new oil line just for ****s and giggles, never liked the hard line that is stock.
New valves and springs - definitely springs, not sure about the valves

Now my ace in the hole is that my company, which sells bicycle parts, has a reciprocal deal with a motorcycle shop. That means parts at shop pricing + shipping = cheaper than I could get them by myself. So a new crank might not be $476, we'll see.

My biggest worry - left over parts! LOL There are so many! I've bagged and tagged each little part. The bags say what it is and where it goes. All those are separated into categories like frame, top end, bottom end, etc.

I know it won't be cheap but life experience never is...

Check with Carrillo to see if they might have a rod that would work? I'd press the crank apart and do the measurements, then call Carrillo. They do one that fits the KLX650 which is way less common.

That's some impressive mileage on the klx. I'm at 67,000+ on my 94 klr250 and it's starting to get a bit noisy as well. I'm not sure how many more miles I'll get out of my klr, but I would like to get 100k out of the little 250. I have an 06 klx with the Bill Blue 351 kit and like anyone else that has his big bore kit it really makes a world of difference on the klx. Post some pictures of the engine rebuild, I've rebuilt a few different klr250 engines over the years and if the klx 250 engine is anything like the klr it's a simple little engine to work on.

MP-sorry to hear about the demise of the engine. I wasn't able to find any aftermarket or oe sources for rod bearing or conrod when mine hammered out the big end . Just lay out the $450 for a new crank and move on. I wouldn't go any further on the head beyond a valve job w/valves and springs. Cleaning up casting flash and matching to manifolds are the only port work I would do-definitely not worth spending any money on. Disassembling the engine is pretty straightforward-the only tools/fixture I had to fab up were to press the crank into the cases. Throw the cases in the oven and the crank in the freezer and it should fall together. Let me know if I can help.

what sort of noises was the motor making when you thought it was just piston slap?

@horror fan It made an extra tick when it hit the top or bottom of the stroke, it was only really audible when the starter was turning over the motor. Everyone that heard it thought the same.

So my question for those that have been down this road. How do I pull out the transmission? The book says yank out both shafts of the trans together with the teeth meshed, that isn't working for some reason I looked for a circlip I missed, but didn't see any.
The output shaft is the one that won't move.

Do you have the cases split? Once the cases are apart you should be able to remove the shift forks and drum, the circli[p they are referring to is on the r/h side of the output shaft. Once you have the drum/forks out of the way, both shafts should lift out of the case as an assembly.

Thanks GB
Yeah, cases are split, shift forks and drum have been removed.
I failed to remember that there is a collar that sits behind the front sprocket. That sucker is rusted in place and I believe my problem.
Working on freeing it up, so I can get it off. I suspect a circlip behind that but maybe not.

For those following along at home and wondering about costs....
So far I have three parts orders.
The crank is/was $428 with a 10% off coupon. :cool:
The bits and pieces part order, which included things most "normally treated" motorcycles wouldn't need, was $484 and so far has only 3 items back ordered.
Those three items also have no delivery date and could be back ordered for quite a while.:(
Two of those I consider really important. One is the carb holder, the other is the carb to air box boot. Mine appear OK but I'd like new ones because mine have been exposed to crazy temperature changes. They've cycled through full operating temps to -30F many times within hours, only to have it happen the next day all over again.
My last (current and definitely not the last) one is bearings and cam cover bolts. It stands at $195.
Add in Bill Blue's 351 for $540 and I'm up to $1647. :eek:
Actually that's not bad for a brand new motor. Used motors were in that range for a stock 250, which this won't be.:D
So far the best new tool added to my collection was the impact screwdriver.
Soon I will try the greasy rag trick on the blind bearing in the case. Hopefully it works. Here's a link to the greasy rag trick :

AvE is great^
Also seen that done with white bread!

Thanks for the update.

Once you are done I would be curious to hear your thoughts on the rebuild vs. buying a low mileage bike and parting yours out. I can think of some obvious advantages and disadvantages to either option, but you will have a perspective that most of us will never have.

The way I see it is who cares what it cost! You enjoy the bike and when done you will know exactly what you have.

Good luck with your build! :)

So I haven't had much luck getting the transmission out because of a part rusted on the outside the case. The part is behind the front sprocket and inside the oil seal. What I'm talking about can be seen in the manual (section 5-2 exploded view of the left side), it's the part between the sprocket and the part with the letter G.
I've spent a bunch of time soaking it with PB and picking out rust from between the collar and the driveshaft. I've also given it a few taps with a punch.
I'm going to have to step up my game because the first box of parts arrived today.

I'm pretty sure that the countershaft should be able to be knocked out of the case with the bearing. I would attempt to do this and then see if that will give you enough access to the spacer to get it off. Use a brass drift or a block of aluminum to prevent any damage to the shaft when smacking it.

Thanks GB, I'll give that a try. My other thought was air chiseling that sucker off the shaft.
Well I've found a few more holes in the frame while removing some rust spots. Going to take it to a real fabricator and get some repair suggestions(like should I patch or replace frame tubes kind of advice).
My crank has finally shipped almost 3 weeks after ordering it.
Now just waiting on bearings to ship.

Max, funny thing on the replacement of some of your rubber parts like manifold and airbox boot. I have a 36-pumper in my '06 with original airbox boot. Over time I've had a harder time getting my boot to mate up and clamp to the intake mouth of the carb...like it was too short. Nothing is loose or broken...like airbox mount, frame, or engine mounts are all good. The boot was still supple and not damaged. I ordered a new airbox boot for grins. Wow!...the original boot was at least 1/2" shorter. I know these kinds of parts can get hard and stiff, but in my case the original boot had literally shrunk but was still supple. Anyway, the new boot fits up nicely to the carb now with plenty of clamping interface. After that many miles it's probably wise to replace the manifold and boot like you're doing regardless of how they "look".

Holes
 

Holes and more holes.
First and third picture show holes that aren't too bad, but the middle picture shows the real damage...
https://cimg0.ibsrv.net/gimg/www.kaw...836f43a3f2.jpg
https://cimg1.ibsrv.net/gimg/www.kaw...9be157aa77.jpg
https://cimg2.ibsrv.net/gimg/www.kaw...290ec2b652.jpg

That is exactly what I found when I recently installed a 300 kit, I mentioned in another post and got no comments. It was definitely the most difficult part of the carb reinstall and am not certain it is sealed completely at the air box end. Time to order new one. Thanks

Funny thing is that the carb boot and manifold are back ordered with no expected date.
We'll see if I get them before I need them, I get the feeling I won't.

It looks like all the damage is up on the subframe?
Do you spend a lot of trail time in water or removal from said water?
Strange to have so much rust (?) damage. Do you live near the ocean?

The bike has definitely seen water on the trails, we have lots of beaver around here. One week a trail is dry and the next week it can be under a lot of water thanks to them.
But that's not what did it.
The KLX was my only vehicle for 3 years.
It went through 3 northern NH winters where the DOT loves to use salt.
Despite being washed at the car wash once a week it still managed to collect salt under the seat rail. It must have just been the spot where all the melt collected and then dried.

Mine was backordered at the time also, but it was probably only another week or 10 days when it showed up compared to the other parts in the order. Apparently it's not unusual for this item...not sure where they're coming from.

So here's the post weekend picture dump.
First is the pile of rust that came out of the end of the frame. :eek: Sorry it's blurry.
https://cimg3.ibsrv.net/gimg/www.kaw...ec4835300f.jpg

Next is the frame primed and almost ready for paint. But first it goes to the welder. Note the passenger foot pegs on the bench. Had a slight issue in removing them. The bolts were free but the bolt and peg seized together (one being aluminum and the other steel) so I had to use a BFH and the one peg didn't like that too much. Since I never carry a passenger, I'm going to put and eyelet bolt of some sort as a tie down point in there instead.

https://cimg8.ibsrv.net/gimg/www.kaw...bacb7bcceb.jpg

And another of the frame in/on my high tech paint booth, lol.:rolleyes: Most of the bike except the wheels and swing arm are on the shelves in the background. Still lots of cleaning to do on those.

https://cimg9.ibsrv.net/gimg/www.kaw...b6c9c45690.jpg

Oh yeah, forgot to mention I got the collar off the drive shaft which allowed me to get the transmission out. Hooray for small victories.
And the crank came out with the not recommended BFH. It pained me to ruin the crank shaft (I wanted to find someone to at least try and rebuild it) but ultimately it's just a paper weight.
All the bearings are out except the ones I have to use the greasy rag trick on. I need to find something that is close to the size of the bearing to drive it out. Only things I have are too big or small to be effective. I think I might try a wood dowel because I can make it fit if it's too big.

Crank has arrived. Bearings should arrive tomorrow unless the Nor'easter screws that up. So that means the bottom end can go back together and it's time to send Bill Blue my cylinder and $500.
Unfortunately, and as I expected, no one (probably because of liability issues) wants to touch my frame. Looks like I'll be buying a MIG and fixing it myself, which I was prepared to do until I found the big hole. I wish I had something to practice on but I don't, other than pieces of flat scrap. I'll have to find some tubing to practice on.

I did a lot of reinforcement of my rear subframe. It looks like that is where most of your damage is.
Don't know what your plan with the welder is..... but, here is my unsolicited recommendation. Cut those sections of tubing out completely, order some more cromoly tubing that the OD is the ID of the good steel, make te cromoly tubing at least twice the thickness of the frame material. Make sure the new cromoly sticks way in beyond the damage as much as possible before re-welding it all back together. If you plan on carrying anything substantial on the subframe, put some bracing on the battery side. The stock muffler offers some support on the other side, if your running a modmuffler, you may want to add a angle stiffener on that side too.
I think I posted my work somewhere on the forum with picks of my work.

Thanks durielk.
This bike will live the rest of it's life as a dual sport. No more rear rack with a box on it, no more winter riding, a little bit of commuting, and a lot of trail riding.
Talking with my friend about the frame rusting out, we think the real reason it happened was the continuous cycle of hot and cold it went through in the winter. That continuous cycle probably caused a lot of condensation to form and let it rot from the inside out. We think this because when we took the bike apart, there was only one hole and a tiny one at that back near the taillight. The more the frame got handled the more the holes appeared. And I found the large one when I stuck the air nozzle down the frame and realized there was air coming out somewhere. A wire brush quickly wore away the last exterior layer and exposed how large the hole actually was.

How is the rest of the frame? Could rust be more pervasive?
We use an ultrasonic thickness gage to measure pipe thickness. I'm wondering if you could find one around to borrow or rent to check the rest of the frame?
T Mike ES Standard Ultra Thickness Gauge with High Speed Scanning and Alarms Alkaline from Davis Instruments

Rust sucks! At this point I would replace it. Many nice ones on eBay with paper work for $300 to $400.

I think you'll use the rack more DS and trail riding, I always take quite a bit of stuff with me due to ... I'm alone, far, far, away. If that rust happened up around the engine-fork-box I wouldn't mess with it, get a fleabay one, much easier and you already have it dismantled, that's got to be 45% of the work done.

IDRIDR - w/o that (HOLY CRAP IS THAT EXPENSIVE) tool I can only guess. I did use a crappy scope and the rest of the subframe all looked "good". The main hole is a spot that when the bike is on the kickstand tends to be the lowest and level, thus a collection spot for moisture. The rest of the frame is amazingly in great shape.

s10gto - I agree rust sucks. Most of the frames that I've found with a title(which I need) are crazy expensive or are for the gen 1 KLX. I just need the repair and frame to make it through the summer. After that I might try and build my own subframe next winter. It's a crazy idea but I'd like to test my skills and ideas.

durielk - I hate having a rack on the back when off-road. It only took one set of whoops for me to painfully discover that. I use an Ogio Flight Vest and Wolfman enduro tank and tank saddlebags to carry all my crap.

Yes, they are pricey.
I found a used one on ebay for around $500. We use it fairly regularly.

Great post, this is Zen and the Art of Motorcycle Maintenance personified. Best of luck my guess is it'll run like a champ for many more miles and will be worth every cent and the time enjoyed doing it.

I think it's time to re-read that book. I haven't read it since I bought my first bike.
So my Porsche/Mercedes mechanic buddy took my frame home with him to repair. It'll be cheaper and he'll fix it as well, if not better, than anyone I'd be able to find.
And he brought me a 5 gallon bucket of parts cleaner!!! So I bought a quart and gallon paint can with lids and a 5 gallon plastic bucket with a screw top lid to split up the cleaner. The stuff is pretty amazing. I spent a lot of time cleaning parts. I dropped the head in the 5 gallon to let the cleaner take off all the carbon build up. I'll clean and rinse that tonight so I can start lapping the valves.
I have all the head parts ready to go once that is done.
I do need to find a spring compressor because I will not be able to put it together the way I took it apart. I used brute force to compress the spring while my magnetic tool was attached near the keepers to draw them out. Like you might've seen in Mr. DuhFactor's vids on YouTube.
I still need to measure the cam chain and see if it needs replacing.
Other than that I'm down to cleaning and taking care of the rest of the bike parts.
And I'm sure I"ll be placing a few more parts orders. I wouldn't mind getting some of those camo side panels from the 2018 KLX...
I've also decided I'm grown up enough to have a hydraulic press. It won't get a ton (pun intended) of use but I've found the need for one at least a couple times a year, so I'm ordering a 12 ton press and a bunch of bearing drivers to finish up the bottom end.

Everybody loves the pictures. Just a few random shots. If I get back into work this weekend I'll post more.

https://cimg4.ibsrv.net/gimg/www.kaw...cd3c8ac6cc.jpgAfter three days in the parts cleaner...the pivot looks like it might be replaced. That bearing, or what's left of it, geez. We'll see what the press can do and what it looks like after.
https://cimg6.ibsrv.net/gimg/www.kaw...bdaf22ef61.jpgThat missing coating was everywhere in the bottom end.

https://cimg1.ibsrv.net/gimg/www.kaw...62414bf53f.jpgPut a mark on my cylinder.
I want mine back. No good reason, but I have a few, and you want what you want, right?
Main reason is aging...I don't want a new shiny cylinder in between the top and bottom end. I'm trying to keep as much of the 64,000 miles worth of patina as possible.

Are you going with a Bill Blue 351 big bore kit? I know I love mine, you won't regret it.