Need some help....81 kz 440

Ok so i just bought an 81 kz440 bobber and am having some trouble with it.

First off I took the filters off to clean carb and filters and the boots for the air filters were torn. But there are no numbers on the filters so I am not sure what filter number or anything that I need. It has a dual carb setup and I believe the filters are the foam uni's but there are no numbers on it what so ever.

Second thing is can anyone give me some sort of idea what the top speed of this thing is. It seems to just not want to go much past 55-60 otherwise you are way up in the RPM's and its just screaming..

And last but not least when i try and start it up, sometimes it will start up and then other times u can just hear the starter grinding. So i am not sure if there is anything that I can do about it either.

Thanks in advance. Ill try and get some pics up of this thing soon just to show everyone the bike that I am working with.

I know you think it's the starter grinding, but I'm afraid it sounds like your starter clutch. Try kicking it over until you are sure it is that.I could be wrong. I hope for your sake I am! I don't like pods myself. I'd try to find a stock air box.If not K&N make the best air filters, If that's the way you're going.

Best of luck! Let us know how ya make out!!!
And welcome, Boots

Well the bike has a welded on hardtail now so i dont think the stock box would work anymore. I live in missouri and the bike has uni style pod filters and chopped exhaust. Can anyone point me in some direction for jetting. The plugs seem a little lean. The jets in it now are 90, 35, and the small screw like one is all worn out so i can only see like its a 38 or 58??? I cant make out what is on it.
If anyone could point me in the direction of good jetting i would appreciate it. It seems like choke always has to be on, and when its on the backfires and pops on decel and when u let out of the gas it seems to want to die rather on choke or not? Thanks

Top speed should be allmost 100 m.p.h.
40 horsepower at 9000 r.p.m.
Uni's are about $35.
I've have a 440 in a 400 frame,but don't run the stock carbs.
You might have the stock jets yet.I have no experiance with the stock carbs but the basics are all the same.
With pods(individual filters like what you have)and a opened up exhaust it will lean out the fuel mixture.Try up (2) sizes on both the main and pilot to start.
ie. 100 & 40 (I think I picked the right ones?)
Do you have a Clymers or Haynes manual for a 440?
This should get you started as long as they are not pluged up somewhere.
Also check your carb to head boots for open cracks.They can be sealed with silicone smeared on the outside.
Never use silicone internally on a motorcycle engine,use 1194 which is called Yamabond etc.

which jets are called which on these bikes. Like which 1 is pilot, main and so on. Does anyone by chance have a part number for the uni, or KN that will fit on these carbs?? Thanks...In what increments do the jets go up or down in ,,,5???? I am so used to working on atv carbs but this dual carb things has got me lost....

When buying pod filters, I believe you're supposed to measure the OD of the carb intake ports - this measurement should correspond to the pod ID.

Supposedly, the stock KZ440 carbs are very difficult to tune when using pod filters. It has something to do w the vacuum slides. If this does indeed seems to be the case, I'll suggest fabbing some sort of air flow restrictor & placing it around them. Doing so would be a trial & error sort of thing. Or maybe get some KZ400 carburetors.

RingB21 wrote:

which jets are called which on these bikes. Like which 1 is pilot, main and so on. Does anyone by chance have a part number for the uni, or KN that will fit on these carbs?? Thanks...In what increments do the jets go up or down in ,,,5???? I am so used to working on atv carbs but this dual carb things has got me lost....

www.armbell.com/forum/index.php?mforum=kz400

try this link
400/440 section has lots of info