I have an 09 klx250sf, i hav had it torn down 5 times doing a big bore kit (savng the details) had exhaust and jet kits and box mods.

Its all back to stock now, had some phantom ticking noises that have dissapeared, and bike runs fine.

My goal is to tour with it now. How do i know its reliable?

 

Point it towards an ocean and see if it gets you there. You now know the bike inside and out, why would you be worried?

 

just noises, scares me but i guess its okay. Not as smooth as it used to be but i guess thats expected too.

 

I'm not making fun, but I had to laugh a little at your question. You say the engine has been torn down 5 times and something about a big bore kit...but...now it's all back to stock. Maybe some details about what happened that required 5 tear downs and such would help answer your question. How many miles overall on the bike now? Overall these KLX250's are extremely reliable. Yours may be too...or it may not make it around the block. You commented that you "have had it torn down 5 times"...so I take it you didn't do the work in these 5 tears downs. My crystal ball is a little murky without some details, but maybe Kreskin is reading these forums, and he can come up with the answer.

 

ok,
installed two bros full pipe and jet kit.
installed big bore kit, wrong head gasket (knock)
re installed kit with good head gasket, puked oil out exhuast
reinstalled stock engine had tick (lost valve shim during cap fall off)
reinstalled head, kept exhaust and jet kit made funky noise
put back to complete stock.

incidently, during one of the installs one of the cam keeper pins fell out and got caught in the cam lobe (eeeek i know) i checked every part VERY carefully. theres no problems there.

did all the work myself.

bike has 3k miles on it.

been riding it for 150 miles beating it to death, no noises with stock stuff.

bam

i guess ill just ride it around town and see what happens.

My next project will probably be stock kawasaki 300 "big bore" i just need a little more power. i dont like the power vs. MPG loss for mods on a small engine.

 

Wow!...that's a lot of bad luck. If you're sure everything is in place and in good order, just keep it around your home area for awhile to see how some ride time checks out on the engine before doing any trips or such. On the touring issue, I don't know. Long distance touring on a 250 isn't my idea of fun on a dual sport, but to each his own. I have an OEM 300 cylinder on my '06 KLX, but I really wouldn't attribute anymore or less reliability with BB's 351 kit...or any of the other quality big bore kits. Your situation sounds more like a learning process during the installation process...with perhaps the exception of the wrong head gasket if that was provided by the supplier. Mods like exhaust, airbox, and jetting do not diminish reliability. Improper installation and tuning efforts affect reliability. Your desire to stay with a "stock" setup sounds more like your just snakebit over all the issues you had. A big bore kit and all the mods totally transform the KLX into a different bike that is also still reliable.

 

I'm with TNC with this.. lot's of sympathy for the myriad of issues though. I bought a KLX specifically because of being tired of working on my other bike.. I wont name any names but the classic color is orange. Anyway, all the issues with the other bike made me a little gun-shy with changes and reliability, but with things done right, I still know it should be right. I just get scared.
I did the full exhaust, jet kit, smog remove and free carb mods on mine recently. My first 2 attempts at jetting were off and the bike was coughing and sputtering all the way through the mid range and was starting with no choke, and literally second jet test ride I was thinking, oh no, did I mess up the carb mods? did I ruin something? have I killed my reliability again? But I started at a medium jet and went up... my next step was putting the idle jet back in a ways and going a size down from the first jet... whala almost perfect, pulled the snorkle instead of buying another size down and smooth as a baby's bum... but much faster. Just gotta get the confidence back I think. However, I'm very sympathetic to just wanting everything the way it was to avoid issues. For the record, the reliability issues on the other bike, didn't have to do with modding or going outside my skill set, was just a tough bike that had some issues to begin with that ran deeper than expected.

 

The noises will come and go depending on where the cam adjuster is at, and also it should be noted that a lot of these bikes tick when first started up and then get quiet as the engine gets hot. Mine does it, I think its just the tollerances getting tighter. Anyway, I would load this bike up and ride for a week without any worries. Besides after 14,000 on my bike, what could go wrong now? A few guys that have been on the site have over 25,000 miles now. Its not a Gold Wing, but it will get you there.

 

I appreciate it guys. I'll just ride it and see what happens. I'll probably wait till winter to do another project like this.

Real dumb question. Does the main jet also affect the needle flow?

 

If by main jet affecting needle flow you mean how much flow goes around the slide needle as it rises ... yes absolutely, this is how your carb works at it's most basic level anything above 1/4 throttle. the bigger the main jet, the more gas that can slip past this needle and the richer your setting will be over 1/4 throttle.

If by main jet affecting needle flow you mean changing how much goes past the screw in idle jet needle on the bottom/front end of the carb, not really for the most part. In some cases going WAY too big will allow an over-rich setting at idle, but off hand, I'm not sure on this bike. I've been in the carb, but wasn't thinking about that honestly.