82 KZ440 LTD only does about 65~70 on flat ground

It's been something of curiosity for a long time, but especially after talking with people about vintage bikes at the AMA Vintage Motorcycle Days this past weekend... I have to figure this out.

I have a 1982 KZ440 LTD and it's in great shape; tuned-up, new plugs, purrs like a kitten when running, belt is proper tension, etc... BUT it has always only been able to do about 65~70mph while on flat ground and all-open on the throttle.

I've heard that 150cc bikes from the mid-60s would top out at like 83... a friend's friend mentioned his 78 KZ400 would do 80+ without issue.

Any ideas? Open forum for brainstorming here...

Thanks all!

-Dustin
Chicago, IL

that does seem a little slow,but then again ive never ridden a 440 does it act like its running out of breath,or just out of gearing?

That's a well-put question IMO. It seems I'm simply out of gears. It has (or at least feels to me) that it has plenty of power in all gears. A friend asked me somethining similar: it is not red-lining when I am in top gear with throttle wide open doing 65-70.

Maybe less-than-optimal compression?

Check the ignition advance mechanism, sounds like it is stuck

I just looked that up in my service manual for the bike... looks pretty straight-forward to get into it and check it out. Basically the service manual says to look for worn-out springs and that the 'flyweight pivots' are not worn or loose.

For my first time diving into this part of the bike, pretty low on the 'eff-up factor' or should I get someone experienced to help me with it?

If the diaphragms in the top of the carburetors leak, does this perhaps keep the slides from opening up? It appears that the 440 LTD uses CV carbs. Anybody know about this? Just a thought.

Never owned one, but from what I've read the top speed on the KZ440 should be about 100mph, although it doesn't get there quickly. Two questions: In the lower gears, does it accelerate smoothly all the way up to redline? I believe it's a 6 speed; will it go up to redline in 5th gear, and if so, what is the indicated speed at that RPM? Ed

if it runs well enough, i would leave the carbs alone for now. my 400 and 440's can pull to a shade under 100mph with my 200lbs on them. that indicated so it is probably more like 90.
i think you can just take off the ignition cover and get your fingers in there and check the advance. it should be nice and clean and move freely. it will only rotate just a little bit, but it then should go back by itself. if you do have to pull the points plate off (an 82' may have electronic igntion but basically the same) just put a couple marks so you can put it back right where it was.
if you do have to pull the advance off the bike make a note of which way it was, it can be reassembled wrong and it will not run when you put it back together.
generally lube it with a light grease or white lube.
it is easy and should only take a few minutes

Hell, thanks FLHT.... i read this and figured i would do it just for the hell of it. I hadnt really looked at that part yet.

It turned out that it was kinda crusty in there and seemed too hard to turn, i took it apart, lightly sanded the mating surfaces lubed it up and it works great. It dropped my rpm's 500 when crusing at 60.

It use to be at 5,000rpm when ridin at 60 now its a tad below 4,500. which is very noticable.

Try it dude, its easy.

Make sure the peak of the cam is pointing twards the (tec) mark if you have a transistorized ignition.

good luck


...luke

Yeah - I am going to look at it today as well and see what I come up with. I'm going to do a before-and-after like you and see when I am at x speed what are the RPMs, etc...! I'll get back with you all and let you know what happened...

550A2 wrote:

...It dropped my rpm's 500 when crusing at 60...

Ummmm.... I hate to tell you this - but that is impossible! The RPMs at a given speed in a given gear are determined by the gearing (unless your clutch is slipping).

It would be my guess that your repair on the ignition actually caused the tach to work more accurately (if it is not a mechanical tach, that is).

With that said, what objective changes will someone notice if their ignition advance isn't right and they 'fix' it? Just higher top speed?