Hi All,

hoping someone can help.

I just purchased a 2005 KLX300R.

Problem: Kick starts on 3rd or 4th kick then dies after 3-9 seconds.

history: Sat for two years, but other than that well maintained. 715 total miles. I changed the oil, and filter, but the oil that came out was practically clean.

choke is out.

opened up the air box and filter, and they look pretty good. No obstructions.

Replaced the spark plug. Comes out clean.

Opened the top of the carb, checked the needle, and it had some weird corrosion on it. Cleaned it up, and now is moving nicely. Pushed my finger into the carb to verify the wing wasn’t seized. It’s not. Moves well, but shot some cleaner in there anyway. Other side I don’t feel any obstructions.

attempted to start with air filter cover off. Same result.

fuel flow into carb seems to be OK…

not sure where to go from here. Wife noted that a lot of smoke came out of the exhaust and there was a backfire when it started for a good 8-9 seconds.

Hope someone can help! Thank you in advance…

-Sincerely, some computer nerd that thought he could get a dirt bike running if he could remember some command line crap to get a few hard drives working.

 

Take the carb off and clean it thoroughly. Old gas can dry up in the float bowl and when new gas is introduced the residue can turn to a gummy substance and clog small ports. You can have a shop clean out the carb or you can clean it yourself using a cleaner like Berryman Carb Cleaner, which can be found at car parts stores or on line. I worked in a dealership and saw all kinds of bikes that had the gas dry out and get gummed up when the rider tried to start it. The shop got a lot of bikes in needing carbs cleaned. I also used the shop carb cleaner to clean some carbs myself (I did some setup and was mainly sales in the shop) with total success. It was rare to need a second cleaning with the washer. But I, as I said, I also have done the cleaning with carb cleaning solution as well.

Take off the carb and disassemble it completely. If you can have a shop run the carb and jets run it in a carb washer or an ultrasonic cleaner for reasonable money ($25 or so) have it done. The machine will work the cleaner into all the passages. Do NOT use any metal wires to clean passages or jets. Using metal wire to clean any jets or passages can damage the soft metal causing flow issues. I cleaned the carb on an XT225 getting a gallon of Berryman Carb Cleaner, runs around $39, has a basket with it. On disassembly I found the float bowl looked like it was bright brass plated, the dried residue of the old gas that had evaporated had coated the float bowl, floats, and anything that was in the gas. Definitely needed deep cleaning.

If you decide to clean it yourself, after reading the directions and wearing nitrile ("rubber") gloves. I put the small parts in the basket, sloshed them around a bit then let them sit for a couple hours then washed them out with water. I put the stripped carb body in the basket and in the cleaner, sloshing the basket around several times over a bit of time to work the cleaner into all the small passages. I left the carb to soak for a couple hours. I washed the parts in water to dilute and clean off the cleaner. If you blow out any jets or the body wear goggles to avoid getting the stuff in your eyes. I don't remember blowing anything out other than with my mouth after washing the parts off thoroughly. Probably should have used my compressor.

I reassembled the carb, turned the idle mix screw out 2.5 turns. Reinstalled the carb, the bike ran fine..

 

Fighting with this thing last night this was what I was afraid was my next step.

appreciate the detail, and advice!

 

I can't add any advice other than encouragement. The tipoff was deposits on the needle. That means deposits elsewhere in the carb. Getting the carb out is a bigger pain than working on it. Once you clean it up you should be fine.

The reason the oil was clear was any deposits in it had two years to settle to the bottom, so after you get it running, I'd do a hot oil and filter change while everything is still in suspension just to make sure anything left over from factory machining gets removed.

For long engine life, I'd also recommend getting a magnetic drain plug. There is no size limit to the ferrous particles it can attract and keep out of circulation.

 

Sure enough, jets had junk in them.

And yeah, much more of a pain getting the carb out to clean it than anything else so far.

Now to see if I can get it back in there without finding a part sitting on the floor of the garage!

 

And we started!

after about 5 kicks it fired up. I let it run for a bit, sputters and backfires, adjusted the idle but still seems to run a bit rough.

Rode around the neighborhood a bit and killed it at a stop sign. Started right back up first kick. Brought it back in and put the rear fairings back on. Again started right back up.

Shut it down for a while and just came back out and it won’t start again. Maybe I’ll try again tomorrow. I must have missed something when I took the carb apart.

 

You aren't talking about crackle when the throttle is closed are you? If so, that is normal for four strokes. You could try putting some Sea Foam in the gas... which I take it you've already drained and put fresh gas in the tank. Get the bike good and warmed up, ride it around to get everything up to full operating temperatures and see if it cleans out.

 

it does sound like a bit of a crackle.

I couldn’t start it again yesterday so I took the carb apart and cleaned it again. Either I missed some crud or it came from elsewhere. In any case put it back together and she started again, running pretty smooth.

Started up second kick today, headed to the gas station to air up the tires and killed it. Wouldn’t start again. Bro in law happened to be driving by as I was pushing it home.

He thinks it’s flooding, and advised a carb rebuild with new jets.

Any idea what the “ideal” for the fuel screw is for just starting the thing? Is it better to try to start backed out then in until it starts and idles smoothly, or in all the way and then back it out to do the same?

First time I took it apart it seemed to be fully turned in.

also, yes I know there’s an aftermarket finger turn mod… it’s a pain in the rear loosening the carb just to adjust this screw a bit, and almost impossible to tell if I’m doing any good or not.

 

You shouldn't need new jets unless you pushed something through them and damaged the passage making it larger. You could check the float level if you think it's flooding. I attached some manuals for the bikes, they're mostly the same since around 1994 for the 300s and from 2006 and up for the 250 dual sports.

 

I'd also consider replacing the rubber tipped float needle.