Don't start!!!
250F Another 2004 KX250F Project/Build
- Thread starter Trfsrfr
- Start date
Clogged PJ wasn't the problem. So I removed the starter jet and the main jet, both clear, and running the OE spec size. The only size difference was the PJ - book calls for a 40, mine has a 45.
This thing wants to run. She fires every 4-5 kicks, and backfires out the exhaust.
I am having issues with the throttle cables getting enough free-play though. Every time I tighten them down at the carb they tighten up. It seems like it fires more when I have the idle screw in a certain range, but everything else is out of whack and I keep making adjustments its hard to know where that is. I had it running yesterday for a minute or two but it was still in pieces and I didn't have a fan blowing on the radiator so I shut it down, but it ran great. Haven't had it running since though. Every time it fires it'll run for a second then die, wont idle, wont take throttle.
Is it a good idea to remove the throttle cables and start there, using just the idle speed screw?
Also, what does the hot start do?
This thing wants to run. She fires every 4-5 kicks, and backfires out the exhaust.
I am having issues with the throttle cables getting enough free-play though. Every time I tighten them down at the carb they tighten up. It seems like it fires more when I have the idle screw in a certain range, but everything else is out of whack and I keep making adjustments its hard to know where that is. I had it running yesterday for a minute or two but it was still in pieces and I didn't have a fan blowing on the radiator so I shut it down, but it ran great. Haven't had it running since though. Every time it fires it'll run for a second then die, wont idle, wont take throttle.
Is it a good idea to remove the throttle cables and start there, using just the idle speed screw?
Also, what does the hot start do?
Last edited:
I did check the cable routing twice and I'm fairly certain I have it correct. Its free and unobstructed anywhere. Doesn't bind up when I turn the bars either direction, they're loose.
After the fiasco with the yz250 I feel like I got a pretty good basic understanding & lesson of the 2T carbs, but now this thing again with the diaphragms and all the other doo-dads has me scratching my head. When I assembled it a couple months ago I went through it real good, checked the (expensive) accelerator pump diaphragm, and it was still pliable, and usable.
And what does that extra carb cable do? Why two?
I definitely have a love/hate relationship with Kawi's now...
After the fiasco with the yz250 I feel like I got a pretty good basic understanding & lesson of the 2T carbs, but now this thing again with the diaphragms and all the other doo-dads has me scratching my head. When I assembled it a couple months ago I went through it real good, checked the (expensive) accelerator pump diaphragm, and it was still pliable, and usable.
And what does that extra carb cable do? Why two?
I definitely have a love/hate relationship with Kawi's now...
Losses return cable to much slack. It will return faster.
Did you just replace them or actually lap them in?
I did both. Which I was told repeatedly afterward that I wasn't supposed to do. I was told that I ruined my new valves, and screwed up the seats.
My YZ250 is 20 years old, and is already my most favorite bike ever.
It'll (or I'll) keep up with any 450, and costs 1/3 the amount to repair/rebuild. Once I get this KXF running like it should, its for sale. Then I'll take the money from the sale and go buy another YZ250, just so I have a back-up in case my 20 year old bike takes a shit. Which I doubt will.
4-strokes are really good for cars...
Cables are about the cheapest option here so I would replace them and see where you stand then, as you said your having issues there so eliminate it as a possible problem!
It runs good. Sounds healthy. Just gotta get this carb thing figured out.
Just got a brand new set in the mail last night.
So I figured I should take another look at the carb and ripped it off.
The float was a little low, not much, but its set at exactly 8mm right now, and I put that plastic doohickey back in that I asked about in Nov.
So next question is the jet needle - according to the PC site that Mike linked to in my YZ250 thread, they say needle position should be set at 4th position, but my manual says 3rd.
Who knows better? (I have stock exhaust). The settings for my YZ worked well, but it does have a PC silencer...
Thoughts?
The float was a little low, not much, but its set at exactly 8mm right now, and I put that plastic doohickey back in that I asked about in Nov.
So next question is the jet needle - according to the PC site that Mike linked to in my YZ250 thread, they say needle position should be set at 4th position, but my manual says 3rd.
Who knows better? (I have stock exhaust). The settings for my YZ worked well, but it does have a PC silencer...
Thoughts?