I have had my 09 SF for about a year now and have done 8000 year-round km on it in that time. *I have duo-sport tires on it and it sees about 70/30 use. *It's been the perfect tool for commuting on weekdays, and getting off road on weekends without needing to truck it there.

My particular bike is not unique in its stubborn cold starting but since I brought it home, I have tried all the common remedies with unsatisfactory results. *Drilled starter jet (first with an .018 bit, then a .019 bit), confirming the float level, shaking, laying the bike on its side, and turning the fuel off before shutting down, all have had limited success with me. ****Slowly engaging the choke used to work reasonably well but I am finding it is now less effective than when the bike was new.

The cold starting issue is my only gripe with the bike and I have considered selling it because of this problem. I am confident that I would have ridden double the Km I did last year if it started more reliably (or even as well as an old British bike for that matter!).*

In my quest for a solution, I mounted a flow-thru primer bulb from a snowmobile in the fuel line. A little squeeze on it while the engine is cranking generates enough pressure to override the float valve and raise the fuel level in the bowl so that some gets through the jet(s) and into the throttle body. *

I have mild concerns about the pressurized fuel doing some damage to the float valve or perhaps to a seal, but so far there has been no problem. *We had some horrifically cold temperatures last week (-32c) and I could get the little KLX to fire right up without even touching the choke.

It's sure not the most elegant solution. *It is more of a coverup for the ineffective choke system and/or the ACR. *It also conflicts with my tendency to want to remove things from bikes rather than add stuff, but it seems to be the solution that will hopefully see me enjoying the bike even more this coming year!

I'll report back if any side effects arise but in the meantime I'd encourage anyone else who has not had good results with any of the other methods to give the primer a try.

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I wonder if your bike is one of those with KACR holding a valve open too long and therefore not creating enough vacuum to draw fuel?

 

@TNC, I wonder the same thing and I'll investigate further at valve adjustment time. *The primer bulb can always be removed if/when the ACR turns out to be the real remedy...

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Have you checked and adjusted valves?

Is there a mouse nest in your exhaust pipe or air box (just joking here...but its happened before).

By the way, there are some old posts on this forum where others did the same thing with the little fuel pump. I don't recall seeing many more do this since TNC suggested drilling the enricher jet.

 

I agree on valves.

 

@IDRIDR & @68: Nope, never had the valve cover off. *I think that you and TNC may have the right idea regarding it being valve related though. I am leaning towards the ACR simply because:
A) I am working off the (perhaps false) assumption that the valves were correctly adjusted at the factory and I have another 4000 Km until first inspection
B) I have no other symptoms of misadjusted or burned valves

I am quite familiar with the mechanism on a manual compression release, but less so with an automatic. *My understanding is that it is similar in principle to an old points advance unit. If so, I am assuming that failure is rare but perhaps an improper return spring could cause an issue with cold starting(?). *I'll check into this in the spring when I am at 12000 Km and the temperatures out in the garage are a bit more conducive to handling chunks of aluminum!

Thanks for your interest in my issue. *The community is one of the great things about the KLX. *I belong to several more forums for my other bikes; their combined knowledge and interest doesn't match what we have here...

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Hmmmm...if the valves have never been adjusted, that would be the first thing I'd look at. Yes, the KACR can produce a similar result.

 

I have the same issue with my 09 SF, it has less than 300 miles on it. If it sits any length of time, I will wear the battery down before it starts. I have to wind up boosting it in order to get it running. Terrible for a new motorcycle.

Once it does start, it runs perfectly. Now I am starting to wonder if the valves or the KACR are out of adjustment.

 

Image showing how the bulb primer sits unobtrusively in front of the rectifier and behind the starter. Hose clamps and a 10” section of ¼” fuel line are also required. Total material cost ~$10.

 

C'mon now...be honest...do you have an Evinrude in there instead of the KLX engine?....LOL!

That's a pretty creative setup, and I can see how it yields results on cold starting. In an extreme case, you can overdo it and get a "lubrication wash" effect in your cylinder with that extra fuel. Still, probably not a big risk if you only do about 40 or 50 pumps on that bulb. Just kidding, of course.

On your valve setting comment, personally I think that perhaps the most important valve adjustment in a bike's life may be the first one after break-in. I think they do a pretty good job of setting up our engines for the most part at the factory, but the valves probably do more seating during the break-in process...or after a valve job...than any other period of the bike's life...though they can start closing fast as an engine gets worn and clapped out.

You need to check those valves. For nothing else but peace of mind and elimination as the cause of your hard cold starts.