1980 kz1000 trike carb tuning woes

I've got a trike thats got a 1980 kz1000 shaft motor with vm28 pumpers on it that for the life of me I cannot get to take off smoothly.I'm at 6500 feet wih pod filters (I know) and some roughly 3 foot long 4 into 4 straight pipe shotgun exhaust.The carbs have the original 110 mains and 15 pilots in it and needle is at the second position from the bottom.Taking off from a stop is a hassle because it feels like it has no power down low and I have to feather the clutch to move.It almost feels like a flat spot off idle under load.Once moving if I roll into the throttle it pulls like a train.I'm really unsure of what the jetting should be at this altitude with such long straight pipes on it.Compressions,spark and advance are all fine and the carbs are clean as a whistle.Unfortunately I haven't been able to get it down the road long enough to get an accurate idea of how the spark plugs are looking.Any help would be greatly appreciated.

Jetting is way lean for open exhaust and pods.

Need to go to at least 120 mains, 20 pilots,

Awesome I'll get some new jets and let you know what happens.I appreciate the help.

You would think at 6500 feet the 115 mains would be about right or even a little on the rich side. I'm concerned about the idle jets being way too lean. Would also account for the sluggish off the line performance.

Honestly the altitude is whats confusing me most.At one point I thought it was the 2.73 gearing in the rear end so I threw a set of 3.55's in and it still had the same problem.Its got a ford 8.8 rear end and a set of 295/50r15s on it so I figured it was just too much tire and bike for the motor.I was wrong lol.

You may have to find a better exhaust system to fully cure the problem. Individual open pipes typically work best within a very narrow rpm range, if at all. The shorter the pipe, the higher the rpm at which it functions properly. For smooth low and mid range power, nothing beats the stock system. That is what it was designed for. Factory pipes in good shape can be hard to find, but there are a number of aftermarket systems, any one of which would be an improvement.

I'm fully in agreement about the exhaust, usually open pipes like that drop performance. And yes that's a lot of tire as well. My 450 hp camaro uses tires smaller than that, you are going to have some issues with that much mass out back with the stock kz final drive trans, etc (just a guess, not a trike guy)

I can confidently say that gearing and tires arent my problem.Surprisingly I'm not too far off from stock ratios.It takes off a lot better when the chokes on so it definitely is a fuel issue.I personally have no issue redoing a section of my exhaust to include either baffles or maybe a set of x pipes for each batch of cylinders if need be.

I'm not so sure that tire size alone is a problem, you're now hefting around two 60+ lb tires on a transmission designed to spin a 30 something lb tire.

Definitely wouldn't try beating on it, cant see the tire going first. Also would imagine it to be somewhat taxing on the clutch etc

the problem with straight pipes is the initial loss of low end torque. Got to have some back pressure to regain that. To test it can be as easy as bolting or tack welding a piece of sheet metal over the exhaust pipes then drill some 1/2 holes in that plate. Start with one in the middle and see if that helps. Then add more holes. You will probably end up with about 4 or 5 holes before it runs good. Still will sound good.

Oh I completely understand your concern.Somethings I pretty much had to cross my fingers on and hope down the road they'll be fine.Luckily with how much trouble I've been having with the carbs I cant beat on it anyway lol.

Have you considered some cheap automotive "Cherry Bombs" or similar glass packs? They add a little back pressure and the fiberglass removes the high pitch "crack" from the exhaust note. Leaves only that low end rumble.