1976 KZ400D Running Rough.

Hey fellas, new to the board and new to Kawis, too. Old Honda guy here, I picked up a 1976 KZ400D for my roommate really cheap, it ran and I've spent a lot of time fixing it up but it runs like shit and let me give you the pertinent information.

Had pod filters and baffleless exhaust. After cleaning carburetors (pilot jet plungers were in good shape, all jets fine and unclogged), I set the points and ignition timing, valve clearances and installed fuel filters. I next set the fuel/float level within spec and bought new spark plugs. Good spark on both, and the bike will start on almost every first kick.

Carbs were bench synced and there's equal pressure out of both exhausts (also both headers get equally hot). It will idle at 1100 just fine, but if throttle is opened it'll stay up around 4000 for a couple seconds then relax back down to idle. When I ride it, it lags on acceleration and stalls/sputters on deceleration. If choke is pulled in after a fast deceleration, it will die. Pulling the plugs they're black as hell. How can with pod filters it run too rich?

I tried putting the stock air box back in (it wasn't cheap) with new boots and it still runs way too rich and runs like shit.

I'm frustrated and want to sell the bike, but do any DIY experts here have any suggestions?

It sounds like someone tried to rejet the carbs for pods and got it wrong (easy to do). I would rejet to stock spec and install the airbox. Also, check for leaky carb holders (let me know if you need instructions) and sync carbs while bike is running (bench sync will only get you in the ball park). Ed

How do I determine that the jets are a different size? There's no indication numbers on them, they're pretty old looking. I'll use my vaccuums this afternoon, see if I can get them synced.

The main jets are 130s. The O-rings are beat up now, I'll replace those. But they're definitely stock size.

I'm pretty sure I've been having the same issue with my recent purchase of a 76 400d. Replaced the boots (checked for leaks), new plugs, cleaned the carbs. Slight leak in one float bowl like a drop of gas every 8 seconds. Idles really nice when first started but stays at 4000 after revving it. Thinking it might need to be synced?

130 should be stock size according to this PDF www.kz400.com/Techh%20tips%20bilder/Stan...%201979%20models.pdf

If the float heights are correct and the jets are the right size maybe it's an ignition problem causing a false rich condition?