[notrocketscience]

Hi all, I hope you've had a better time than I have with your bikes. This post is a bit of a doozy so I added a TL;DR at the bottom.

For a bit of background, I have a 2006 EX250F that I bought used last September and have been attempting to fix up since. It's in pretty rough shape but has just over 6000 miles on it.

Things I've done:
- new battery
- new spark plugs
- cleaned and sealed gas tank
- cleaned petcock
- added inline fuel filter (for a lawnmower, I think John Deere specifically)
- cleaned carbs
- set carb float height to ~16mm (used depth gauge to get height from the lip of the bowl to the top of the floats)
- brand new gas (~costco regular~)
- set fuel mixture to 2 turns out instead of 2.5 (I think this helped get it running better when I was messing around with it today)

Today was the first time in a while that I've tried to start my bike since making the improvements. I turned my petcock to on and then cranked it for a while to prime my carbs, then when I tried to turn it over for real it fought me a bit and then gave me a pity start that lasted for a good 3 seconds. I tried starting it a few times after it quit to no avail, got pissed, then called it quits for a little while.

I remembered back in October I seemed to have success when I was either just filling my carbs after emptying them or when I set the petcock to off and starved my carbs of fuel. I have no idea why this was but it let me bike startup so I didn't ask questions.

So I did the same thing, I set my petcock to off and tried cranking it some more. After messing around with the throttle for a bit, I finally got the bike to start and it ran great! I shut it off and tried again to see if that was just a fluke, but it started right back up and let me reset my idle tuning to have the bike around 2k rpm (where it ran comfortably). After a bit of smooth idling, I noticed when I messed around with the throttle it lagged pretty bad. I figured this must be a fuel issue since I'm starving my carbs of fuel and I turned my petcock to on. After that, I ripped the throttle and it was quick and snappy. However, my moment of celebration ended pretty quickly because when I let off the throttle my bike slowly chugged to a stop yet again.

The bike seems to have a sweet spot when I'm starting it up where just the right amount of fuel is in the carburetor. I really don't understand it, but that's the best idea I can come up with right now. It may be a float issue, but I don't see how I can bend my tabs more to lower the fuel level further. Hopefully, there's something simple I'm just missing.


TL;DR - My bike doesn't idle and is incredibly hard to start when my petcock is on and my carbs are full. When I turn my petcock off and my carbs are full, my bike idles incredibly well (comparatively) but the throttle lags when I open it up. setting the petcock to on after it's already idling gives me good throttle control for a moment, but the bike slowly chugs to a stop.

I want to say it's a float issue, but that doesn't make much sense to me. I was hoping someone else may have had a similar problem or at least could offer me some guidance on what to mess around with.