Rebuild KZ 440 or buy a different bike?

I need some advice. I currently ride a 1980 kz 440 ltd and it has treated me extremely well for 5 years. However I find that 440cc's just isn't cutting it any more, and the bike is starting to show it's age. It was pieced together by my brother as a bonding poject between him and a girlfriends dad from two different bikes, then he never got his endorsment and never rode the bike so he sold it to me . The motor is starting to run rough and knocking. The clutch is getting sticky and sometimes I have to really muscle the shifting when going from 3rd to 2nd. It's also burning some oil as well as has leaking a bit (there are oil droplets all over my driveway from the various places I park) and cannot tell where it is coming from as the whole lower portion of the motor is covered in oil. Also I recently changed the oil as well as the air filter and now it stalls out unless it is nice and warm (the old air filter was reeeeally dirty) so I suppose this means I should adjust the carbs but just haven't gotten the time to research how to do that (as I am currently in the middle of moving).

So here's the delema. I also have the other half of the 440 which my brother took parts from. So I was thinking this winter I would do some research and rebuild that motor. Then in the spring piece that back together in a cafe esque style with dropped bars as well as new exhaust and carbs.

OR I have roughly $2000 saved with which to buy a larger bike such as a kawasaki z1 900, honda cb 750, yamaha xs 750 - 850, suzuki gs 750. Something along those lines.

I would like something that is capable of highway speeds round 70mph without straining. My current 440 doesn't like to go above 65 and is round 5100 rpm at that point. It can hit 70mph but it is not happy about it and gets very hot and it worries me doing that for any long distances. If I was to rebuild the 440 parts bike that I have, would it be happy doing 70? or would it be about the same performance. Also - adding different exhaust and carbs - from what I have read would be difficult without a starting basis of a running bike to tune it up properly. Im no mechanical wizard - I can do basic repairs but have never taken on anything as large as rebuilding a motor or fully tuning a bike. I have the shop manual in the mail though and am sure with enough dedication and research that I could probably figure it out. Or am I just getting my hopes up? On the other hand I like the idea of the self gratification and connection I would have with the bike upon completing my goal and would learn a lot in the process.

or just get a larger bike?

thank you for taking the time to read about my predicament and for any suggestions and advice.

-mike

Get the bigger bike.

Keep the 440 pair and build your cafe racer....at a later date. Find you a KZ900, KZ1000, or maybe GPZ1100. But stick with that old school Kaw reliability! And then....... Ride ride ride!!!

Get a bigger bike, you won't regret it. My 250 was mint but was a lot of work to ride on the highway.

Get a bigger bike. A KZ1000 would be good if you can find a nice one in your price range that hasn't been hurt by modifications, but even a KZ650 or 750 should satisfy your requirements if you find one that is in stock trim and runs well. Ed

Bigger Bike sounds to be the answer to the query. But how is your riding experience? Bigger goes faster and weighs more, won't be a nimble etc. So there will be a learning curve to go up, unless you have that sort of experience already?
A bigger motor can be geared for the higher speed as the engine can pull a taller gear ratio. Then you can Cruise at 70 easily, but your stop and go traffic will be more difficult. A good compromise gear ratio would be best.

5 years on a 440? You should be ready for a bigger bike. Both my brother in laws said I'd want a bigger bike than my starter kz650 in less than a year and they were right. They knew they'd be right because they both outgrew their starter bikes in a season. All three of us are over 6' and 225lbs and I have to admit I make my 650 look kind of small. Plus Michigan speed limits go up to 70mph and the 650 starts to vibrate pretty bad over 60mph. Smooth as glass under 60, but on the couple longer rides I've been on, it's rough to sit on for more than an hour at cruising speed. Around here the best cc per $ bike is in the Yamaha XS1100 but the seats are so high you have to be tall to ride one. I did pick one up and I'll be putting it on the road in September (hopefully). Just test riding the XS11 is exhilarating, 40mph comes along real quick and I still have two more gears! I think you'll like a bigger bike, maybe even consider a liter or more.

If your KZ650 is vibrating pretty bad over 60mph something is wrong. Ed

Around 60-65mph it starts to feel like I'm holding on to a blender and sitting on a garbage disposal. It took me a while to realize why I kept backing off when I got close to 70mph, it just doesn't feel like it wants to go that fast and it's a physical change in how the bike rides, even flat in a straight line. My one brother in law had a Vulcan before his Harley and claimed that Japanese bikes are like that. Smoother than Harleys at high rpms. But they have a speed the like to cruise at and while they'll go faster, it's just harder on the rider. That sounded exactly like what I was feeling, like I could ride all day at 55-60, but 15min at 70 and I want a break. Maybe something is wrong with the bike, but I'm already in around $2400 with it, so unless it's something relatively minor like fork oil, I'm not going to get too deep into it. Once I've spent some more time in the XS11's saddle I'm going to decide if I want to keep the kz for an around town bike or sell it to get another liter bike and bob it.

Apologies for the thread jack.

did it sit on flat tires ever? Have you had the tires balanced to check if you have lost any weights?
I was told by a shop that they just leave the current wieghts in place if they dont balance the wheels. Old tires were a lot more out of balance then the new tires are, so this type of thinking can throw off the balance. also have you check rims for run out?

Well, the tires on it are new this season Shinkos. The place that put them on removed the old weights and put 4 adhesive weights on the left side of the rim opposite the air valve. The place is trustworthy and *everyone* in the area recommends them for import bikes. They tightened the spokes but didn't true the wheels. The front end does bounce a bit in the 30-35mph range but it's gone by 40mph but that feels completely different than what I experience at 70. I think the bounce might be cleared up with new fork oil as which hasn't been changed since the 80's when this bike was barned (I resurrected it, this is its first season since '82-ish). From what I understand in the kz650's the engine bolted directly to the frame where later bikes like the 1980 XS11 used rubber bushing mounts to reduce (this type of?) vibrations. But if everyone thinks this is weird, maybe there's more to it than what I'm thinking. Still don't want to spend much chasing it down though.

My 650 ran smooth all the up to it's limit about 120 MPH. If yours is shaking somethig is wrong.