Bike runs flawlessly on full choke only

[Katarat]

You need to make sure the paths from the air jets to the plot jets & passages are clean and the hidden path from below the pilot jet to the idle mixture screws are all clear. I learned that the hard way with about 8 carb R&Rs & finally sawing an old carb in half & finding the hidden passage. The air screw passage was blocked thus no air to let the fuel flow

[jakeh]

Hey guys! Awesome news, yall were right, the pilot fuel passages were completely clogged. I got jipped on the "professioal cleaning". it took several hours but we finaly got the passages and jets clear. After reinstalling, we started the bike on choke as usual and slowly took it to open choke. Idled great! pilot circuits working!

New problem. When throttle is applied two bad things happen. One: I get a serious lag/bog before it winds up. Two: it takes FOREVER for it to wind back down to idle.

My hypothesis is that ironically now that were running with correct choking, we have a rich scenario? would that explain the bog as too much fuel to burn and the slow wind down as residual fuel in the venturies?

[Steve]

Thanks for being humble enough to follow suggestions AND being man enough to admit what you found.

Now for your new "problem". A slow return to idle is typical of a LEAN idle (pilot) mixture, not rich.

I am not going back to previous threads to see what carbs you put on there, so please remind us ... what size are they? If they are much larger than stock, you will have some bogging when applying throttle, just because they are too big.

.

[jakeh]

They are keihin PD round slide carbs. same size throat and same stock intake boots were used. the only difference in diameter is where the filters attach it is only 42 mm. So the slow return to idle would be caused by the pilot? Huh, learn something new all the time. in the morning I will try and plug chop it during a bog out to learn more on the fuel flow condition.

[jakeh]

So knock on wood everybody.... this morning fired up the bike to do plug chops, fired up and idled nicely, no choke (its also 104 degrees here in Houston today) first few neutral rev attempts resulted in slight bog, after it warmed up. It revved freely and smoothly. Hopped on and took her around the block, rode smooth with good power. It still takes a little longer to come down from free revs than I would expect, but then again Im used to my CRF250R with basicly no flywheel to speak of. It is probably reasonable. Plug chop showed greatly improved but not yet ideal conditions, they are no longer bright white, but not quite to a target brown. Im sure I can jet and tune that out.

My only concern now, when free revving it in neutral at lower rpms, when the revs are released and the bike comes back down to idle, it makes a notable *gargle* sound out the intakes for lack of a better description. I assume that is noise that it always makes but can only be heard now that the pod cones are in place? I hope so. And sometimes when idling, theres a light click about every second I cant seem to find. I figure it cant be anything very severe be it such a slow click. Something anyone has ever heard of?


Thank you all for all of the help. I would not be able to do this without it