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View Full Version : KTX500 guys(or carb gurus)having an issue with starting



danimal95
01-24-2010, 03:09 PM
on my KXT5 i have a hell of a time starting it,i dont believe it is just my kicking procedure,here are the symptoms:starting from cold,i have the kill switch off and kick it slowly through the range 2 time to draw fuel in,i have also just attemoted to start it with the switch on and gave it hell right off the bat seemed to make no differance,choke fully on it will pop through the xhaust a few times but wont fire....i can then shut the choke off and kick it,sometimes it will fire sometimes it will just pop some more,if it continues to pop i have to hold the throttle wide open and then it will fire.obviously this tells me that it is too fat,however when it is running it will idle fine and have really good throttle response.which makes me hesitant to change out the pilot jet.also it should be known that i have to kick this thing between 10 and 15 times before it will fire,and usually 3-5 times before it will even pop out the exhaust.when it is warmed up it will restart and the 1st or 2nd kick......any ideas???

harryredtrike
01-24-2010, 03:13 PM
go up on the pilot jet.not fat at all.bigger pilot will not affect your throttle response

Racerguy381
01-24-2010, 03:26 PM
First, what are you running for your air filter set up. If you just have a pod filter and no box it will affect your jetting alot. The stock 500 set up with the airbox is even restrictive for that big motor. Your jetting will be lean if your just running a pod cause of all the extra air your getting to the motor so you need more fuel. Like Harry said go up one on your pilot. I think that bike had a 45 pilot, go to a 48 plus check your needle clip position. It should be in the middle move it down one and try that.

danimal95
01-24-2010, 03:57 PM
i am running a pod filter,already adjusted the clip down 1,seemed to make no differance for starting,it did clean up the rest of the powerband.wouldnt me having to hold it wide open represent a fat condition???

JohnR.
01-24-2010, 04:00 PM
It would unless holding it wide open like that is getting the fuel in that you need to get it started. A backfire pretty much always indicates a lean condition or if it had the original T3 motor a stator on its way out. LOL! The needle being raised shouldn't have any effect on closed throttle starting. I would try going up on the pilot as was suggested. What carb is on that thing?

Racerguy381
01-24-2010, 04:07 PM
The KX500's all ran 39mm PWK in the 90's and up models. That pod filter will definately need more fuel. Moving the needle clip affects your mid to wide open throttle. After you get the pilot adjusted your most likly going to need to go up on your main jet also. Probaly the 2 sizes bigger on the main, you wont know for sure till you can actully ride it. When you get to that point get a good spot to do some good 3rd or 4th gear roll on plug checks.

JohnR.
01-24-2010, 04:09 PM
I figured that's the carb it used. Fantastic piece IMHO, I've been running one on my 250R for 15 years now.

Racerguy381
01-24-2010, 04:29 PM
Same carb I have as well, instant HP on a 250R. It was a huge difference soon as I put it on turn that thing into a whole different trike

danimal95
01-24-2010, 04:41 PM
It would unless holding it wide open like that is getting the fuel in that you need to get it started. A backfire pretty much always indicates a lean condition or if it had the original T3 motor a stator on its way out. LOL! The needle being raised shouldn't have any effect on closed throttle starting. I would try going up on the pilot as was suggested. What carb is on that thing?
yeah i never looked at it that way,i agree on the back fire being lean,im used to having toi go WOT to start a flooded car(injected)it is the PWK39mm

Racerguy381
01-24-2010, 05:24 PM
Just a good starting point and usefull info for jetting
http://www.eddie-sanders-racing.com/oscmax/article_info.php?articles_id=2?osCsid=3955a95e05b5 70142bc7aa94d8694ba6

jeffatc250r
01-24-2010, 06:08 PM
They all have their little tricks to get them started. The best starting 500 ive ever seen is the one I sold over the summer. I should have kept it. After I figured it out it was simple, tip it on its side till gas came out the carb, slowly kick it over 2-3 times with the throttle wide open, then find tdc and go PAST it a little, choke back up on the kicker and give it one hard slam and it would always start one kick. Try going past tdc like I just said, It may work. If you tried it at tdc you could keep kicking till you were blue in the face and it would never start with the last bike I had.

danimal95
01-25-2010, 07:40 PM
so i did some looking today,it has a 52 pilot and a 168 main...i swapped in a 55pilot and left the main as is,does the same exact thing...kick a few times gets a pop out the exhaust,turn choke off,and it almost fires w/o touching the throttle....were do i go fom here???

Racerguy381
01-26-2010, 11:46 PM
Check your air fuel screw, make sure its at 1.5-2.5 turns out When it does start up how is the idle with that pilot? Some of my bikes just plane dont like any choke but run fine with the jetting that I have in them. Try going up again on your pilot to a 58 and pick up a main as well. Depending on what year your engine is the stock jetting jumps around alot through the years. A few years ran 60 pilots and 172 mains while others dropped down to 55 pilots and 168 mains. This is the crappy part about jetting its trial and error till you get it right especially with your open pod filter your most likely going to be up in the 175 or higher on your main. Keep us posted.