No diaphragm on these Recons; they use a slide carb, not a CV unit.
Very simple and reliable.

My bet would also be the battery (OPT). A bad battery is a problem, and
a BIG problem if it is totally missing or so bad that the regulator can
raise the voltage at it's terminals to an unclean 15+ volts. The battery
regulates the voltage, too.

I currently have a 99 TRX250 Recon here and found (for the first time)
a dead bug inside the carb float bowl. Wow.

 

That's not rare for those old Recons. They had a lot of bugs but Honda has worked them out over the years.

 

Hey guys, problem seems to be fixed....

I rebuilt the original honda carb with the air stop valve with a kit sold at the local 4x4 store and I didn't see any improvement in the surge. It did however start MUCH easier and stayed running a little better. Also felt more responsive. Replaced the plug and had a tiny improvement in idle but still stuck at low rev when goosing the throttle, misfired, idled crappy etc...

I popped the valve cover off and found one valve to be dead on at .005 clearance but the other rocker was touching the valve stem. I backed it out to .005, put it back together and adjusted the idle.

Bingo, no surge, smooth idle, starts right up and stays running no problem. No more sticking throttle either and no popping on deceleration. only thing is I may have to close up the lash a tiny bit as when it warms up I am getting a louder tick than I ever remember having (this isn't a chevy). but it runs good now.

Only issue I am having is the plug looks like it may still be running lean, with 3 turns out on the pilot jet. As I understand it, this is too much and it probably needs the main jet needle dropped a notch. I'll post a picture of the plug and see what you guys think though...to me it seems like it may just be on the verge of being a little lean but maybe not....I am not used to reading new plugs and I don't have a lot of room to test this thing at my house so I am limited to some 1st to 2nd gear pulls in the back yard. It feels good though and no popping out the back.

It still feels just a little flat up top....but that maybe is the way it always was (it always had a lot of torque I know, but it's been so long since I rode it maybe it never really pulled hard up top). Also thinking maybe weak valve springs or clutch slipping (doesn't feel too good anymore) causing the lack of top end power. With the way the clutch is you have to be really careful when you drive it of where you shift/how you ease into the throttle. Can't really go WOT through all the gears anymore or you get some slipping at the bottom of some gears.

 

Also just wanted to know if there is anything i can do to save the clutch for a little longer? Oil additive or using any particular oil/weight? I always used to use Honda oil but I just did an oil change with valvoline 10w40 before working on it. Clutch seems to be acting up more than it did the last time I drove it a few years ago.