99 fe400 erratic throttle

I have posted this question in the electrical area of the forum recently, but I haven’t gotten much of a response. The suggestion I have so far is to check the float bowl spec, I intend to take the carb back off and check this just to rule it out, however while I’m in there I was wondering if anyone has any further items I should check out, and is there a measurable spec I should go by for the float height. Does any of this sound familiar or typical? I'm not sure if it’s electrical or fuel?
Hoping someone can assist with this. I have a 99 fe400 with super low hrs. It ran fine 6 mos. ago, but now I have a problem with high speed running. It starts fine- choke on 2 kicks, choke off - 1 or 2 kicks and it starts right up on idle. Throttle response is normal thru 1st , 2nd, 3rd gear, at the top of 4th is seems to hold back a little and when I shift 5th it starts to sputter and jerk quite a bit at low to mid throttle, it’s pretty erratic, if I give it full wick throttle it dies like there is no fuel or spark(stalls), when I let off it kicks back in. 6th gear is also erratic , even more so than 5th it also seems to stall with full throttle as it tries briefly to go, blubbering and lurching. With the throttle completely off in 6th it stalls as well, give it a little and it comes back. I’ve had the carb off/apart and cleaned and blew out everything I could find & changed out the fuel, I thought for sure I would find a clog in the main as I’ve had this before with my other bikes. Also changed the plugs, pulled off the stator cover too see it looks like new, tried adjusting the carb air screw (which didn’t seem to help just made it harder to start). Is it possible an electrical component is failing? Am I missing something in the carb a passage or something? I bought, this bike used with only about 75mi on it and it ran great, I haven't ridden it much because the stock suspension didn’t suit me, I just had it all done by enduro expert in NJ, put some short bar risers on it with a softer seat, I thought I was ready to ride but now I need to iron this thing out.
I would really appreciate any help/ ideas you guys have.
Thanks - Bill

Thanks Dale for the good info, I will contact Sparks asap...

best regards - Bill

Thanks for the stator info Sparks,
I checked the ohms on the stator
red to black - 2852
green to black - 166
seems ok - right
I will do spark performance test tommorrow, but what about the ignition coil/module?
I was wondering because if the spark is weak when I do the spark performance
test could'nt it also be a faulty ignition module, rather than the stator?
If possible I would like to test that as well before I ship the stator off for rewinding.
Can the ignition module be ohmed out ? Is there a primary and secondary coil in there that can be tested? I think on this bike the CDI is built into the ignition module with the coil(s), but not sure.
thanks to all for the help so far - - Bill

We'll I sent my stator to Spain and had "Sparks" rebuild it for me and still had the same problem. I bought another ignition coil off ebay and put that on to rule that out and still the same problem and yes I checked and cleaned all the grounds and repl the plug with iridium . So now I'm back to the carb which I have cleaned already (but maybe not good enough).I read a post where it was said the float bowl height was too low causing a lack of fuel that resulted in the same problem I am having.....Can someone give me the specifics on the proper height and where it is measured so I can get this baby running right - - 1999 FE400 w 38 dellorto PHM carb everything is stock on the motor.......Thanks

I am open to suggestion, but before I start replacing parts on the carb let me say that this bike has a max of 180 miles on it ( 290 kilometers ) its almost like new. Do you still think I should replace all those parts or maybe a just few of them would able the bike to run better. I know the throttle reponse was never great but it starts so easily and ran good I was leary of messing with the jets. For right now anyway I just want to get it back to where it ran before and then I can make improvments. It ran fine, then it sat with fuel in the carb for about 6 mos and then began with this problem. I cleaned the carb 1st and had no effect, I hope I have just missed something . It did seem like the spark was blowing out, as was suggested, but now that the ignition seems to be in order I need to take another look at the carb. It starts easily and runs good until I get to 5th gear give WOT or if I lug the motor and give WOT in all but the lowest gears she hesitates & bogs out. I think found the info I needed on setting the float bowl and a good exploded view of the carb to work with. If not I guess I'll be lookin you up Taffy.
Anyone else have thoughts on this ?
Regards & Thanks.......Bill

The mileage is accurate, I bought the bike in 2004 from a friend who bought it as a leftover in 2002. He was a 2 stroke rider and never took to it, he had it in storage when I got it with 75mi on it. My case is that the suspension was not right for me, I have other bikes I ride and have always worked a lot of overtime (until recently) and just never had the time to dial it in. I have started it like monthly and sometimes took it for a short spin at the farm next door. It is all original except for the raised bar clamps, bars, and handguards the original tires still have the nubbies. The guy Ron who recently did my suspension at Enduro Experts in New Gretna, NJ told me he would not ride it as its in museum condition, but I want to ride it thats why I bought it in the 1st place.
Enough said about that, I guess your comment challenged my integrity or something.
Thanks for your continued support...I will also look at the timing when its back together
Regards - - Bill