RD350 forever project

[Perattzi]

Howdy everyone, back again trying to get my RD ready for street riding season. Fired up first kick. Nice. Went for a little ride and noticed once the bike is warmed up, it will still fall on its face when leaving from a stop. I basically have to rev it to 4k to take off. Would seem my jetting is rich. Curious if my baseline is in the ballpark?
New 5ah battery
Charging @ 14.5 volts

Stock porting
DG pipes
Y boot with uni pod
Vintage smoke ign @1.8 btdc
Brand new vm28's
Dave f mod
2.5 slide
210 main
27.5 pilot
169-p2
2.0 air jet
5dp7 needle
Needle clip 4th from top
Air screw 1 turn

From what I see others running I'd think I'd be in the neighborhood, but it's pretty much not safe ride as is. Super frustrating. Thanks for any tips!

[1976RD400C]

Looking at your specs, it may be rich, especially the needle clip on position 4 but it should still pull away from a stop without falling on its face. Being lean would cause that. 

[pdxjim]

I agree. Running well when cold but hollow when hot generally describes a lean condition.

Wrap some blue tape around the filter and see if it runs better or worse.

[Perattzi]

Thanks y'all. Yeah it feels like a lean bog from a stop. After that it feels rich. I know most people have good luck with the Dave F mod and the 2.0 air jets but don't those lean out the 0-1/4 transition?

Also couldn't get the bike to start at all after pulling carbs. Chasing my tail til I realized I installed one of the slides backwards 😂 in all my years never done that ONE lol

[teazer]

Air screw is only 1 turn out from fully seated suggests that it needs larger pilot jets.

4th clip position should make little difference at closed to say 1/4 throttle.  But after trying one size larger pilots, try lifting the needle and see if that helps the transition.

[m in sc]

I bet its the needle

[Perattzi]

https://youtube.com/shorts/2LUUtI2ckAs?si=wsw2--ijE05l_Mjn

Made a (crappy phone in jacket pocket) video of the 'falling on its face' my bike is doing from a stop or when slowing down to about a 1st gear turn. When I get back on the gas it just bogs hard as you can see in the video a few times. I raised the clip one slot and also changed my pilot to a 30 to see if that helped. It mostly did not. Strangely my air screws seem to have very little affect when I adjust them. Like the idle doesn't really increase or decrease to find the sweet spot. Once on the needle jet it seems to pull pretty hard.

[JKV45]

From my experience, having a uni-pod filter, instead of an airbox, always flattens out the low and midrange throttle response and torque.

Some of the issues may not be able to be fully resolved with jetting.

[RDnuTZ]

drop 1 tooth on front sprocket?

[m in sc]

if nothing else adding a runner ahead of the carb bellmouth makes a big difference

[1976RD400C]

I would experiment with continuing to move the needle clip to different heights.

[Perattzi]

Thanks guys. It is odd bc my setup hasn't changed for years and it never used to do this. Feels almost like it's running out gas like when you need to flip to reserve, but only occasionally when going from dead stop or like I said a very slow corner. In the video when at first stop sign then a bit later you can hear it just bogs hard for several seconds. Not sure if it was apparent.

[JKV45]

Float levels correct?

Petcock screens in good condition?

[Perattzi]

Float levels correct?

Petcock screens in good condition?

Yeah should be. Tank is clean and carbs are barely used, I set the levels. I'd think I'd see a fuel starvation issue on longer wide open pulls and I don't get that at all. Anyway I'll tinker. Thanks for the input.