Lately, as in for the past week-ish, my bike has been difficult to start. I can go out in the morning after not riding all night, let the bowl fill up, pull the choke, and it'll start after a few turns. The choke has started to pull itself in, and if it dies, then it's difficult to start with or without the choke on. Likewise, after riding for a while, most of the time when I go to start her up she'll have issues. Just sitting there cranking and spinning, but not firing. Every couple of rotations it will act like it's going to start up, but it won't.

The battery is fine, and I've had it on a tender which only seems to help a little. The starter engages fine, and spins the motor with ease, but it just doesn't fire up. The only thing I can think of is that the spark plug may be bad, but that doesn't make sense to me when I can push it through my yard to bump start it with no problem. I know I need to install a kick-starter, just waiting on several paydays and dividing funds to different parts of the bike.

So would a bad plug be causing my issues starting, or is there something else I should be looking for?

No, I don't have the MCM done, and haven't messed with the KACR (whatever that means or stands for).

 

A restricted pilot jet can cause starting problems as well as intake valves that have run out of clearance, a common problem with the KLX300.

Ride on
Brewster

 

heck yea a fouled spark plug can cause a no start.

especially on small engines.

had a brand new BRAND NEW, generator, tried to start it in the dead of winter, had to use the choke, finally got in running, for a minute, then forgot about again until I needed to use it to run some power tools away from the house.

the generator would NOT START brand NEW?! I took the carb apart, nothing there. I usually don't fool with the carb, unless in this case, its just one bolt holding the bowl on the carb. so simple on and off, so I did anyways....nothing there.

then I pulled the plug, black soot, fouled plugs, the tip of the plug was black, however you want to look at it, it was dirty with unburnt gas.

took a piece of sandpaper and got all of the black soot off the side and center electrode, and with a towel wiped any residual dirt off, put the plug back in the generator, and that puppy fired up.

that was the problem the whole time,

in short, yes a plug can make something not start if its fouled, causing a no spark condition. no spark. no fire. you need fire to burn the fuel.

 

I would forgo the kick starter & mod the carb & check the valves (you didn't say how many miles you had). If the elec wouldn't start it I doubt that kicking it over is going to help.
There is a mod for the carb on the forum somewhere here to ease starting. Also while your in there, check that the float 'floats' and the float level is set correctly.

 

if the choke is pulling itself in, then I would start there. have that part of the carb rebuilt.

 

Check the lines running around your choke and see if they are pushing your choke in.

On my 2006 KLX250S all the hoses and wiring running around in front of the choke **** seem to push the darn thing in sometimes. I'll choke it, reach up to start it and it won't start, reach down and the choke is in. I have to move stuff around with my fingers, and then it will stay out.


That isn't going to cause your other issues, but its an idea to look at for the choke pulling itself in.


What changes have you made to the bike since the starting issue started?

 

Makes sense Brewster, but at the same time I don't think it's a restricted Pilot Jet because the problem is intermittent, not consistent. I'll have to check the threads here to find out how to check the valve clearances.

KLX250, I've had several lawn mowers get returned to my store with the same kind of issue. Bought at the end of the season, used once and let sit all winter, didn't start up in the spring. It's either a bad spark plug, or the valves are stuck and gummed up. If I can motivate myself to get out to the bike I'll check the plug first. I'm sure there's a thread on here about reading the plug to know how the bike is running. What I'm not quite understanding though is if the spark plug is bad, why would I still be able to push start it with no problem?

Durielk, I had already planned on doing the kick starter, just hadn't thought too seriously about it until my issues began. I've already adjusted the carb to my exhaust, header, and air filter, and the floats were doing just fine. I'll have to search for that carb mod thread then. Also, I've got about 10,600 miles. The electric start will start it, just not all the time.

KLX250 I think the choke pulling itself in is actually a fault on me. After I rejetted my carb and put it back on, I didn't check the routing of the hoses from the bottom of the tank. Going back through the pictures I took before disassembly, I found that they went on the front side of the choke ****, and now they are above it routed to go behind it. I believe this may have something to do with it as they make more contact with the **** now.

Toomanytoys84, yeah I know the two thick tubes from the bottom of the tank got routed wrong when I put it all back together, my fault entirely for not paying enough attention. I was just so excited to hear my new exhaust. I really haven't done much to it. Rode it a little bit, changed the oil and filter, cleaned and lubed the chain, and attached my battery tender cables.

 

My KLX250 is pretty finicky. I try to start it every week or so if I am not riding it, otherwise it gets to be a hard starter. I wonder about the choke resetting- I need to use that most mornings to get things moving.

This season, it was a bear to start and keep running. I wound up having to pull the carb and clean it- there was a bit of varnish in there. I also noticed the plug was fouled with black soot, so I backed off the fuel screw a quarter turn and now the bike runs better than ever. (I just have the airbox/snorkle mods, FMF exhaust and mild rejet.)

 

I agree that it is a bit finicky. Likewise, I use the choke to start the bike, and after the few seconds it runs on the choke and pops itself back in, the bike will idle just fine. Before my rejet, if you pushed the choke in too soon it would just die. It may be running rich, and more than likely it is the spark plug, but I'll have to check tomorrow after I get home from work.

I've only had it for a couple months so I don't have much to compare too, except that a buddy of mine had one last year and he's been able to help, although his was completely stock as was mine until I began working on it. He did tell me that after the bike is warm it will start without the choke if you give a quick flick of the wrist and blip the throttle at the right time. While I was waiting on all my parts to arrive for my temporary upgrade, this worked almost flawlessly! There would still be times when I would miss my window, or the engine would have cooled down too much, but it worked. It even worked a while after my exhaust and rejet, but now I just can't seem to get it right. He tried it once after I wasn't able to get it started with the choke on or without the choke and wot. We weren't really in a place to push start it, and I was already exhausted from pushing it. Somehow he was able to turn the key, click the starter and twist the throttle just right to get it to fire right up. Hopefully I'll bump into him soon and see if he can help me out a little more.

Testify4, which FMF exhaust are you running, and what rejet?

 

It has been my experience that touching the throttle during starting is the thing NOT to do, unless it is flooded. It is a CV carb, your just exercising your wrist.