klx300 carnage!!!

So I recently got a klx300. I went to install a manual cam chain tensioner, and found this when I removed the old auto tensioner


That's a big ol glob of weld bead on the end of a tensioner that's maxed out. Verdict- stretched cam chain....

And this- improperly timed cams (you know, to account for the stretched chain) can't see it well, but there's supposed to be 32 pins between marks. I counted 31 on the mark



Then this. Intake valves. The exhaust looked great.

Meantime I powder coated stuff, while waiting on parts and machine shop


Pretty nice looking scooter when its put together


Anyways, I get all the parts back. I honed the cylinder myself, and installed new rings. New intake valves, cam chain, and resurfaced valve seats.

Apparently I made the elementary mistake is installing the front chain guide incorrectly. Such a rookie mistake cause I was in a hurry.... Then... Chain jumps a tooth. Can anyone guess what happened next?

If you guessed "the piston met the exhaust valves", you're correct!


Now if you look really close at the picture, it almost looks like it broke one of the exhaust valves, and possibly bent another, but I can't be sure... Opinions?


On a serious not, I got really lucky it didn't really tear stuff up. New exhaust valves are on their way, as well as an 80mm piston (sleeved cylinder)

A new bore, ANOTHER cam chain, new exhaust valves and seats, and well be back.

And I'll be trading this for an xr6

dang the bad luck

The days of home installed valves are really gone..
...
1: unless you have even mid priced carbide valve seat cutters (Like the Neway )which do only a marginal job,,, your not getting concentric, correctly surfaced seats
2: The low cost of a perfectly machined head done on million dollar CNC centers is cheap these days.
3: The best your going to do at home is lap the seats,,, what about the guides which are often damaged when a valve is bent or broke like that.

My suggestion is send the head to motorcycle head specialist like Fast Heads.. it will come back fresh, perfect and at a reasonable cost.

And you might want to check that rod..... most times I inspect a motor that was damaged like that I find the rod is bent.

Sorry for the downer news...but that's they way I see it from my experience.

The seats were cut, and will be cut again by the local casting repair service/cylinder head guy. He does everything except replate cylinders, (which he farms out to millennium). Really nice shop, and really nice knowledgeable owner that doesn't mind stopping what he's working on to look at what you've got, and offer suggestions.

The rod and associated bearings are good. I looked the rod over really close (been there myself) and checked for bearing play (up and down) on the big end bearing

thrill-billy85 said:

The seats were cut, and will be cut again by the local casting repair service/cylinder head guy. He does everything except replate cylinders, (which he farms out to millennium). Really nice shop, and really nice knowledgeable owner that doesn't mind stopping what he's working on to look at what you've got, and offer suggestions.

Click to expand...

Nice,, well done

I use millennium as well for all my boring and plating

I was going to say it would be simpler and maybe cheaper to just replace the head with a new one, but I looked it up and due to serious demand VS supply issue Kawasaki wants your first born as well as a arm and leg for a new head.

Yeah, and if you look at the damage.. Its not THAT bad. The machinist is gonna weld up that knick between the exhaust valves, and reshape it with the carbide cutter. He's confident it'll look good when done, and I trust it will. Nothing touched the intake side of the head, so my new valves and seats there are good as well. Like I siad, I got REALLY lucky

Funny what you said about Kawasaki wanting your first born... Even ebayers want him too. One guy was selling a USED head for more than factory OEM new.

I know I could always get a head from a Loncin yf300 motor

Just use the casting.... Not gonna lie, I thought about it...
http://www.easeagent.com/item/38942439186

thrill-billy85 said:

I know I could always get a head from a Loncin yf300 motor

Just use the casting.... Not gonna lie, I thought about it...
http://www.easeagent.com/item/38942439186

Click to expand...

probably the folks that make the engine for Kawasaki!!

Im pretty sure it is. I've researched it pretty hard, and now I know that just because its written in the internet does not make it fact, I've read from several sources that Loncin has BEEN making the klx300 and 250 (now) motor. Its no secret these motors have always been assembled in Taiwan either

Tell us more about installing the front chain guide incorrectly .... You are going to be an expert once this is all done.

thrill-billy85 said:

I know I could always get a head from a Loncin yf300 motor

Just use the casting.... Not gonna lie, I thought about it...
http://www.easeagent.com/item/38942439186

Click to expand...

Glad you only thought about it. We've seen how well "Parts from China" perform over the long term.

Well there's 2 different ways it can go. The ACTUAL way its supposed to sit appears to be incorrect, and not have much holding it in place. The way I installed it looks correct but creates a fulcral point about midway down the guide. This is not only wrong, And will cause premature guide wear, but it also contacts the exhaust can sprocket, which, when revved, pulls tighter on the front side of the timing chain (where there is supposed to be zero margin for slack), and and introduces the see-saw effect on the guide there by kicking the bottom of the guide out of the slot its incorrectly resting in, into the correct position, which introduces slack on the front side of the can chain... Jumps a tooth.... Blamo!

chaissos said:

Glad you only thought about it. We've seen how well "Parts from China" perform over the long term.

Click to expand...

To be fair, if its an OEM Loncin part (which the ad claims it is) then its manufactured in Taiwan, in the same foundry the OEM Kawasaki part is

This picture illustrates the PROPER guide placement, and the green line shows where I (incorrectly) placed it

Great infor and photos. Let us know how she runs when that day comes and maybe we can see you in the Sam Houston National Forest.

Will do. I love riding there. We used to ride 2 strokes there and would stash gas at the road crossings before we unloaded. Me on my old cr250. This was a ported, decked retired hill climb motor. Scary!!

The new piston is in. I've been a fan of Wössner pistons for a long time. They make Wiseco's look like door stops IMHO. Anyways, I expect to receive a call from the head shop this week, and I'll be dropping this little nber off with the cylinder for boring, and matching...

Very nice!! I hope she runs as good as she looks!

Bike is done! She lives! Starts super easy too. With the mis-timed cams it felt like you were kicking an xr80 before. Now is a bit of a different story. That ACR mod suddenly seems like a worthwhile endeavor, as the stock ACR timing is so bogus.

Pics

Glad to hear the good news .... I hear those bikes handle amazing!

sandman said:

Glad to hear the good news .... I hear those bikes handle amazing!

Click to expand...

They do indeed. USD forks, 226 lbs. MX style rake. I'm on my way to trade it now for an xr400, with a pumper carb.

Good move.

The KLX300 is a great entry level trail/recreation bike. Its light, nimble, starts easy, makes smooth predictable power, and requires little maintenance.

That's great for some. Me personally, not so much. I've been riding, and racing harescrambles since I was a child. I'm by no means good, but I'm way faster than your average Joe at the outdoor park on a Saturday afternoon. Anyways, I need more bike, at 200 lbs. Not to mention, I love tinkering with stuff, on a pro-am level.

I was form between an xr4, and a 650l. I like the idea of a 650l because I could hop on, ride to Arkansas, ride trails all weekend, and ride home. Well... Kinda.

I like the xr4 because of the weight, power, looks, and the abundance of cheap aftermarket goodies. Some may argue the aftermarket for the 650l is just as good, but I say they're wrong. If you're one of those, say so, and I'll prove you wrong. .

So the question rises- what about the road manners? Well the xr400 can have them with the right combination of gearing, and motor. How much lighter, and better handling can you make a 650l? Idk but I know the xr4 in stock form is great for trails, fire roads, and logging roads.

I looked at what the majority of riding would be for me. It'd catch the most miles hauling me to work. I take a series of county roads for the 12 miles to work, with the exception of TX-64, just outside Tyler for about a mile and a half. The fastest I can legally go at any point is 55mph. The rest of it, will be exploring the VAST network of county roads, (most dirt) and trails that stretches all over Henderson county, and literally starts (for me) across the street. If I wanna take a trip to Arkansas and go exploring, the bike (be it an xr4, or an xrl) is going in the bed of my pickup, until I at least get to a motel, and what I'll describe as the center of the web of trails/roads to explore. I'm not gonna ride a dortbike all the way there, 650l or not. So.... Xr4 it is.

I've been searching for both for some time. Found some great deals, some insane deals, and also some head-scratchers. Why gotnme psyched was this one xr4 a dude brought to my shop for me go fix. The exchange went like this (in a nutshell)-
Cool bike, what's wrong with it?
It won't start, I'm pretty sure its the carb
Okay, I'll check it out
(Testing, no spark, troubleshoot, bad coil)
He bro, your coil is bad
How much is it?
$30 for the coil, $20 to install
OK, I'll just come get it
OK
(2 weeks later on phone)
Man you sure its not the carb
Yes, its the coil, I tested it per the clymer book
Okay

So today I see it on craigslist for $1000. Still won't start. The new owner is at a loss, and just wants as much money back out of it as he can get. So I call him. He explains it doesn't have a spark, he bought it from a guy that couldn't figure it out. The guy replaced the stator, cdi, and put an XRs only mikuni pumper carb on it. I said okay... I'll come get it. (Already sold the KLX for 1500) go over, pay the guy a grand, he loads it up, and boom. I'm the proud owner of a Honda Xr400r, pumper carb and all. The carb has 0 run time, and isn't even installed correctly. Funny thing... The bike STILL DOESNT HAVE A NEW COIL ON IT. Its a 40 Honda part, 20 on eBay. Instead its got $400 in electronics, and $400 in brand new pumper carb. I bought the rest of the bike for 200. Lol

Build thread starting immediately following this important announcement.