Thinking About Throwing in the Towel

Alright... so... I dunno... looking for some practical advice. :S

I've got this '76 KZ750 (twin), see. I've had it for almost 2 years. It was in rough shape when I bought it (but it would kick-start). And it's still in rough shape. I never rode it. But I spent a lot of time and money replacing some things on it, including a rebuilt starter that won't even turn the engine over (I don't know if it's the starter, the start clutch, or what).

There aren't a lot of parts available for it, nor are there many of these bikes out there anymore. I wanted to get it started and sell it off to someone that knows more or could put it to better use... but now I can't even kick-start it. So now, I'm thinking about just parting it out and buying me a newer bike that I don't have to sink money and elbow grease into. Although, with the low number of these bikes on the road, I wouldn't even know the best way to pass it off to someone else.

To be fair, I bought it to learn how to work on a bike... and my situation is a bit different now and doesn't really afford me much time to work on it anymore.

So I dunno... ya'll are more experienced than I am. Any thoughts? Things I didn't think about? What would you do?

Everyone is different, some have the time and experience as well as the much needed money to deal with an older bike in rough shape. Most of the time it is not a money making proposition but a enjoyable tinkering to bring it back to life/ hobby.
So it is completely up to you. If you think you would be better off with a bike that runs, is newer and better shape, so you can spend time riding and not tinkering. the I'd say do that. Get a Better Bike. Something still in the KZ line if it suits you, or go completely the other way. Get whatever you think will fit your comfort, riding skill etc. Most rider go through several bikes, and may have one or two favorites that they won't part with. Probably have to Kill them to get it. Wives/ girlfriends be dammed! Not selling!
Maybe you can find something that you'll fall for? :kiss:

You may want to consider re-examining the basics before throwing in the towel. In order to run, an engine needs compression; spark (at the correct time); and fuel (mixed in the correct proportion with air). If you have these three things the engine will run; if not it won’t. If you can identify which of these components is not fulfilling the engine’s requirement you may be able to fix the problem and get the engine running.

Compression can be easily tested. If it’s good you can move on to another item. If it’s bad, you can diagnose why and then decide if the repair is too expensive to pursue. A compression test can tell you if the compression is sufficient. If it is not; a leak down test can help you identify where the compression loss is occurring. This is the one item that could prove to be expensive to repair (i.e. bad cylinder, holed piston, etc.), but it just as easily may be very inexpensive to fix (i.e. insufficient valve clearance).

Spark can also be easily tested. Lack of spark could be easy to diagnose and very inexpensive (i.e. loose wire, bad battery, etc.) or it could cost a little more if an electronic component has failed. Often, the lack of spark or spark not occurring when it should can be corrected by a simple tune-up (points, condensers, setting of points gap and ignition timing, new plugs, lubing of timing advancer), so performing routine tune-up/maintenance tasks is a great place to start.

Fuel mixed in the correct ratio with air, can be inexpensive to achieve, but it can be frustrating if modifications have been made to the carbs. If your bike is stock (i.e. air box, exhaust, jetting) the carbs may simply need to be thoroughly cleaned, and you may benefit by adding an in-line filter if foreign matter is coming from the fuel tank. If the carbs have been tinkered with, you may find a clear-tube test shows improper fuel levels, or you may find someone has improperly changed jetting. Either of these conditions is easily remedied if you’re using stock equipment. If you do not have the stock air box, tuning the carbs (rejetting) will require a bit of experimentation. Tests can be performed for vacuum leaks after the engine is running.

The electric starter problem is secondary because the kick starter is all you actually need to use the bike.

I suggest you take another crack at diagnosing the problem(s) before selling or parting out the bike. If you can take a methodical approach and pin down the problem source to compression, spark, and/or fuel you can then move to the next level and diagnose why that component is not supporting combustion. You may find that once you have positively identified the problem the actual repair is not particularly difficult of expensive. Ed

Look at my avatar and see a KZ750 twin with over $4k invested :woohoo:
Look in my shop and you'd see a ZX11 and a ZX12 with "lots" of money invested, so much so that I refused to keep track, or I'd wear my leg out kicking myself in the butt.

And I do all the work myself, except for cylinder boring and plating, and resizing the rods.

If you have a lot more money than time, by the newest bike you can afford. Motorcycles are maintenance intensive, even a new one requires care and upkeep.

I am in the middle of tuning up an '81 kZ440 with a modified intake system, I haven't yet got it perfect so I may not be the best person to take advice from, but I have definitely learned a few things over the last year. Confirming what Ed has said, if your bike has stock components such as original air filter and jets, chances are it will be relatively easy to get it running.

Spark and compression are easy to check. A decent compression tester is maybe $40 on Amazon. However low compression probably isn't the source of not being able to start it two years later. Do you have fresh gas? If you haven't already, put new spark plugs in it, they're $5 a pair.

Make sure to get the original spark plug number even if the plugs in your bike now are different- NGK B6ES for your bike. The link below will bring you to a forum that shows you how to look up any part off your bike on Kawasaki's website.

A practical first step is to investigate whether you have the stock air filter, or if individual pod filters have been fitted to the carburetors.

kzrider.com/forum/13-bike-related/376734...-info-on-kawasakicom

I think I'm just a littel frustrated because I feel like I'm in over my head.

My "plan" was to get it running in its stock form and then do any modifications I might want. So I replaced the airbox, air intake boots, new air filter, starter, stator cover, and transmission cover.

I don't know anything about carbs, and am leary to begin diving in... at least until I get it running again. My goal for this summer was just to get it started so it doesn't have to sit through another winter without being run. The longer it goes without being run, the more frustrated I get.

I did drain the tank and put fresh gas in. I also replaced the plugs a couple weeks ago. Although, this is weird: In the Maintenance section of the service manual, it says B8ES is the best general use plug. The plugs I pulled from the bike were 7s (BP7ES). And after doing a little research, it seems like 8s are generally the way to go (for a stock bike), but they were shipped to the showrooms with 6s because of the repetitive startups they went through on the showroom floor.

Now that you said B6ES, I double-checked the service manual. The Maintenance section does specify 8s for general use (but also to use hotter/colder as required by the individual bike). However, the "Specifications" page says B6ES.

So... Hmmm... OK. I think what I should do next is inspect the old plugs carefully (I kept them) and perhaps try a hotter plug, depending on what the old plugs "tell me".

I shouldn't get ahead of myself here; first things first it has to start. The specific plug doesn't matter so much for starting as long as there is a fat blue spark (It will matter though when it comes to tuning - same thing with the air filter).

Unscrew the plug and ground it against the aluminum engine and crank the motor, then do this for the second one, there should be a real obvious spark. If you see a good spark on both plugs, move onto the carburetor (normally you would check compression next, but I'm assuming it's good because it fired up two years ago).

Make sure there is no rust in the gas tank - if there was and you fired it up before, you could have easily plugged up the pilot jet in the carburetor. Rust needs to be dealt with right away. Even if there isn't rust, it is possible the gas has varnished up the pilot jets to the point where it can't start (Just a guess, but the pilot jet diameter on my 440 is probably .010" to .015" - very susceptible to clogging). At a minimum I would soak the pilot jets in carburetor cleaning fluid (not the aerosol spray, but the actual soaking can). Though in the long run, the entire carbs should be cleaned.

If it's warmed up, a twin engine will run off just one working cylinder , but it doesn't have much of a chance on a cold start like your bike. So even if one little thing is wrong with one side of the engine it's probably messing up your starts. You need to find that one thing, and my guess is that it's in the carburetors. You don't have to dive into carburetors and be an expert to get the pilot jets cleaned.