I had been rebuilding my KLX after I had blown the head in Dec 2018. See original post here!

The bike sat for 6 months before I started to rebuild it. I had purchased a used engine from a seller in Arizona with only 4,000 miles on it vs the 20,000 I had put on my bike. I brought it back to my apartment, ordered a Bill Blue 351 kit and started to rebuild the top end. I had the ports polished and replaced all the gaskets. Between school and work, I took about two months rebuilding it, making sure everything was torqued down to specs. I spent a weekend swapping the motor with my pops. The bike surprisingly fired up within 10 minutes of my first try. I was so pumped! I couldn’t believe it.

However, it wouldn’t stay on without the choke out. I cleaned the carb, made sure jetting was good and made sure the boots were sitting snug around the ports. I kicked on again and I rode it around the block with the choke out but she wasn’t strong. I was so baffled.

I called a trusted mechanic here in CA who works primarily on KLX’s and is familiar with the 351 kit. I explained everything I had done and what exactly was going on with my bike. I dropped it off with him and after having it a few weeks, he called and told me the journals are ruined. He said that I applied too much tension to the manual cam chain tensioner and ruined the journals. I'm super bummed about this as it was my first bike and first time rebuilding a head.

Unfortunately, due to the current Pandemic, I can’t afford to pay him to polish the journals so I'm here to part it out and sell it.

I'm listing below everything that I’ve installed on the bike that isn’t stock.

351 kit (cylinder and piston)

FMF Powercore - 3000 miles

FMF Powerbomb - 120 miles

Race Tech springs - 300 miles

Race Tech Gold valves - 300 miles

New DID Chain (Installed on the bike but has not been rotated)

New Lithium Battery - 1 hour


Everything else is on this 2009 KLX250s is pretty much stock so ask and you shall receive!

Again, I'm hella bummed about this. After having an XSR900 for a year, I missed my KLX and was really looking forward to the day I could ride her around again. The XSR is fun and modern but damn, something about riding a slow bike fast is more fun than riding a fast bike slow!

The KLX sub has been so informative and such an important platform in the knowledge I've gained in motorcycles. I fell in love with motorcycles because of the KLX and this forum. Thank y'all very much!

 

I am so sorry to hear that. I wish you had either kept the instructions or gotten with me on readjustment of the cam drive. I have the instructions online in a Google document and am more than happy to send a copy to anyone any time.

Maybe one of the moderators here would set up a "sticky" on manual tensioner adjustment. Here is the link to the google doc click here for KLX250 manual tensioner instructions If they want to put the document in I can set up a post with it.

I would recommend anyone using my or any other manual tensioner consider making a copy of this instruction sheet in their Google Drive if you have it. Not just open it, but click on file and make a copy so you have it should my drive be closed. You can also get a MS Word copy from me by emailing or messaging me with your email address. I will send a Word attachment for you.

One of the problems with the terminology is that this part is a tensioner. That is a misnomer, it is an adjuster, to adjust the slack in the chain to near zero without putting tension on the chain.

Again, regrets hearing the situation.

 

Hi, I sent you a private message about some of your parts.

 

pm sent
thanks

 

did you end up selling the powercore? haven't heard anything back

 

OK OK I admit I had written this post before I actually had the bike back in my hands. This past weekend, the mechanic (4 Stroke Works in Hesperia) who worked on my head notified me he was able to get my bike running and charged me close to nothing for the labor so I've decided not to part ways with my KLX just yet. Sorry for the inconvenience y'all!

On that note... After running my KLX for about an hour yesterday, the longest ride on it since I blew the head in 2018, I noticed she's now running hot .. but only on the right side. The radiator fan is practically on the whole ride. However, the "overheating" indicator never comes on. Jerry (the mechanic) told me he messed around with the carb and threw one of his carb kits in. There is about a 3000ft difference in elevation from where his shop is located to where I live in Los Angeles.

Is it possible for the KLX to be running too lean?
Is it common for these bikes to run hot with the 351 kit installed?

I just ordered some engine ice coolant to see how that effects the heat. Any other suggestions appreciated!

Connor

 

you check the plug color? if the fan is going the whole time something is off

 

Will check the plug tomorrow.

Is there a history of failed water pumps on the KLX?

 

not that i know of

 

Ok so I checked the plug now and it doesn't seem to be in good shape. Cant tell if the ware is from a lean mixture or from the bike being so hot.

I also want to add that I've noticed a burning smell since I got the bike back. It doesn't smell like burning oil or coolant but rather burning metal. Maybe its from the header being so hot?

Im really scratching my head over this one y'all. Any suggestions are appreciated.

edit: The bike now only runs while the petcock is on the "reserve" position.