KZ750 Won't Start

Hi All,
So I just bought my first motorcycle today, a 1981 KZ750 LTD H. I bought it with the intention of fixing it up and learning about motorcycles/engines along the way.

So trying to get it to start, it doesn't want to turn over. Like an idiot, I didn't check bother to check that it was completely out of oil and only after trying to start it all day did I finally realize that. But that didn't fix my issue. When I try and start it just makes a grinding noise. I popped off the oil cap and it looks/sounds like its the transmission not engaging. The guy I bought it from said that he was told it needed some valve work, but I don't see why it wouldn't start because of this.

I've checked the cylinders and they don't seem flooded. I've been able to get it into gear and push the bike and watch the pistons move up and down. I've also checked all my plugs and they all are sparking. My battery seems like its working (need to get a multimeter tomorrow) but my lights all pop however when I try and start the bike everything electronic dims.

I also uploaded a video of the noise its making. If anyone has any ideas it'd be super appreciated.

And in case I'm doing it wrong I have the clutch in and the bikes in neutral when I'm trying to start it.

Your battery sounds dead. Could be connections, maybe.

I think the battery definitely was bad. I went and swapped it out with a brand new 12V battery. It doesn't dim anymore when trying to start it so I think thats good. I also cleaned the connections up a bit. It still makes that noise but just keeps going instead of cutting out.

I put 6qts of oil in it and just emptied the tank and I'm going to put some new fuel in it. Any other ideas what my issue may be?

****UPDATE****
IT LIVES!

New gas, new oil, new battery, new fuses, drained the carbs and some patience and eventually it came to life!

WOAH! Six quarts is way too much. Most of these old kritters take less than 4. That much oil can create serious, expensive problems. I'd recommend draining 2 or 3 quarts out, then filling up to the top line on the sight glass and no higher.
There should be raised letters (numbers) on the top of the transmission case near the oil filler that tell the oil capacity. Something like, 3.9l. That would be 3.9 liters.
Get a genuine Kawasaki Factory Service Manual and read about these things before doing the work.
Even the Clymer manual should give you the correct amount of oil for that engine.

Definitely too much oil.
Steve

Glad I said something. I'll get it out of there tomorrow. And I have the manual on order I was just a little too eager with it sitting in the garage.

I ordered the Clymer manual because I couldn't find a regular one, is there a big difference?

It's a one size fits all. Can give you bad info. Good work on getting it started.
Steve

you will find a pdf copy here mbsween.bike-night.com/kz750l3/manual.html which covers your mode as well as the others like the E1 E2 etc
The Kawasaki shop manual is much better that the others

Oil filter & air filter. If it hasn't been done yet, I would install a new oil filter --- there's no telling what the old filter's condition could be. I would also install a new air filter. do not over-tighen the airbox cap as the old plastic could crack.

Engine oil. use a motorcycle oil or Shell Rotella 15W-40. or other heavy duty diesel engine oils, such as Chevron Delo, Valvoline Premium Blue. 15W-40 may not be good for cold starts during cold cold weather, though.

Battery. be sure to keep it fully charged. the bike needs a good battery to run right. AGM batteries seem to hold their charge better than the wet-cell batteries. Scorpion AGM. Ctek US 0.8 smart charger. VC97 digital multimeter.

Manual. search eebbaayy for KZ750 manual. Kawasaki factory manuals have a model application chart on the back cover, Here's one that might go for cheap. 80-82 KZ750 four .
Here's a site w a pdf manual & wiring diagrams. mbsween. bike-night. KZ750L3 . Scroll down & click "The Bible" link.
Note: some of the wiring diagrams are mislabeled in the links: the 1981 Ltd is an H2, the 82 is an H3, & the 83 is an H4.

+1 what Martin wrote.

The Clymer manual is generally fine for routine maintenance and such. The 750 engine was used in several models, but the Clymer does not always do a good job with the subtle differences or sometimes the more intense repairs.

congrats on getting it started, now make sure to drain that xcess oil out!!!

Thers a ton of valuable info and users here, depending on your plans on the bike, you may get mixed reactions...

just make sure that if you intend to start chopping things off, or replacing parts, that you keep the stock parts in good condition. plenty of people here would like the stock stuff.

i have the same bike, kz750, mine was partially bratted before i bought it, and ive continued that process. Ill be glad to help you with anything i can, its been a journey getting mine going. Before this bike i had never worked on anything more then changing my cars oil. Thanks to a factory service manual, and this forums great memebers, ive been able to replace internal engine parts and rebuild almost every aspect of my kz. You can do the same@!!

let us know if you need anything!

chris

Thanks for all the help guys. I got the oil out and she runs great. Also did an oil filter swap while I was at it so I feel much better about the whole thing. My Clymer manual just showed up so I'm going to try and return it and get an actual factory manual. Thanks for the PDF link tho, that definitely helps. The next step once I get a real manual is going to be getting it up on a jack and tearing it apart. Theres definitely some filth that needs to come off. Theres plenty on the internal side that definitely sounds like it could use some work but I figure it'll probably be a bit easier once its off the bike.

I'd definitely like to keep it as close to stock as I can in the end. I've been looking for inspiration online and found this, and I think along that lines is going to be the goal, with a little more bronze. But thankfully I've got plenty of time.

Thanks again for the help