Hi Gang,

I have owned my KLX for about two years and have read most of the theories on why some have hard starting issues and have applied most of the tweaks to my bike. I was beginning to wonder why no one looks at the KACR as a prime suspect for hard starting... until I dug up an old thread "Money Pit" where KLX678 mentions disabling the compression release and having near instant starts (along with proper jetting).

I "BELIEVE" that since it lights off right away if it has sat for less than a day or two, and another poster said he never has any starting issues when he keeps his KLX on a Battery Tender - it seems a topped off battery spins the motor fast enough to "overcome" the over-zealous KACR.

I am not ragging on the KLX, I love it but have never been happy with its willingness or unwillingness to fire right away and do believe it is the low compression at cranking rpm that makes it reluctant to fire right away, even when properly jetted.

So I am asking:
- How is it done?
- Are there any obvious negatives like reduced starter motor life?
- Did Mama Kawi design the KACR for no reason?

Am I way off base? Is it not this simple?

TIA and God Bless,

TC

 

I had a KLR650 for 60k miles and 17 years. It had a KACR that was never disabled. This m/c was always an instant starter no matter what, cold, hot, sitting for a month or so. I have a hard time believing that the KACR on the KLX250 is any kind of a root cause for its starting problems. The different suggestions on this site do help a lot in making the KLX easier to start, but mine, anyway, still isn't up to the starting ease of the KLR650.

 

I removed my KACR when I had the top end apart for a valve check and doing the MCM. Preferred method is probably to press it out, but I used a hammer and a long bolt through the hollow camshaft and eventually convinced it to separate. Based on what others here were saying, it doesn't seem like the KACR is necessary on our electric start KLX250's. Mine never had trouble starting beforehand though, so I didn't remove it for that reason. However after removal, the bike does seem to start even easier. Can't speak to how it will affect long term starter durability, but all good so far. Another less permanent option is to leave it installed in the camshaft, but disable it with a piece of wire (described in detail in other threads), if one wanted to try that way first.

 

Or simply pull the spring off of it.. That is the easiest way to permanently disable it.. I would drift it off the cam if I ever "go back in"... I re-indexed it, when I did the MCM, and now wish I'd just left it off..

 

Yes, just remove the tiny spring.

 

I'm not saying that this is a fact, it's just my observation, but my bike has started flawlessly after opening the exhaust valves to the more open 1/2 of the range. It did not start well before. Almost always needed choke to start, except when the motor was hot it only sometimes needed choke
When you are in there for the KACR, it'd be a good time to shim the valves.
There also might be an acceptable range for assembly that the factory goes by...maybe some of us have more properly adjusted KACR than others from the factory?

 

You wished you left it off? Starting issue? I just did the MCM and have no staring issues after I reindexed.

 

My bike starts instantly - as should every well done MCM ( As long as there is nothing else wrong/outta adjustment)... When I did my MCM, it was not known that the KACR is useless..

 

The biggest culprit in the hard starting is probably the lean jetting. It is definitely the cause of the long warm up.

Thing is the KACR is a waste on the 250 and does affect starting by letting out some of the fuel charge. Just a fact of life with it.

Honda has no compression release on their CRF250L and Yamaha has no compression release on their WR250R/X. It is unnecessary with electric start. It is a hold over from the early kick start only KLX250 and KLX300.

It is one more unnecessary moving part. In my KLX650 I had the spring come off the shoes twice. I pinched it up a bit on the hook end hoping it will stay put. The 650 does work better with the release. On my 250 I locked the shoes in the disengaged position with some wire - just happens that a common coat hanger has the right size malleable wire to do the job.

Next time I do the valves the release system will be pressed out and probably trashed.

 

Thanks for all the input guys!

I think I have the lean jetting addressed. I twisted the .018 bit through the starter jet, replaced the pilot jet with a #38, and have the pilot screw almost 2-1/2 out now. It starts fine if it only sits a couple days, and I can close the choke after about 15 seconds of high idle and ride away smoothly. Oh, and the rest of the DJ kit also...

I recall now, reading about someone's starting issues going away after adjusting the valves, thanks for the reminder Maximus! I also appreciate your point about manufacturing tolerances on both parts... I rode with a guy at the Rally in the Gorge last weekend with an '06 KLX that was an instant starter - hot/cold/ anything in between. The owner never "held" the start button, just bumped it and it jumped to life! Being the second owner, he did not know if any carb or starting mods had been done.

One other thing Maximus - "more open half of the range..." I assume you are talking about one end of the range of acceptable valve clearance. Do you mean "smaller gap" when measuring clearance so the valve "opens more?" OR, do you mean a more open (larger) measured clearance when adjusting the valves?

I suppose a good place to start, once winter sets in, would be to adjust the valves and disable the KACR? Does anyone disagree that removing the little spring would be an effective way to disable it, at least to see if disabling it helps? (I'll read up on the different techniques to disable it.)

I have read casually about the MCM but never really considered it... though it seems that everyone who has done it feels the altered cam timing is a benefit.

Thanks for the insight, it helps me look at the situation from all the angles!

TC!