Good find! The "wiggle all the wires and see if it does anything weird" method has worked out for me a few times too lol. The years are not kind to these old wiring harnesses, but mechanically they just run forever. Stay hydrated down there.
Guy I went to school with rode that same model early 80s to school collectable now poor seller back then so was the cbx remember left over sitting on the showroom at the local honda shop in slidell la for two or three years after they came out think you have an electrical glitch itll rear its head again if you dont find it first
I had a '78 750B3 that did a frame-off restomod on, but I made significant improvements to the electrical system, including a blade style fuse box and electronic ignition. I re wired many of the connections because they were old and corroded out, including the one that gave you trouble in this video. But I still ahd an electrical gremlin that needed to be chased down now and again. Eventually, though, I got it sorted to the point that I felt comfortable taking it on longer rides. I spent many lovely hours on my precious KZ. They're super fun bikes. Enjoy the ride!
Love this bike. Nostalgic from my pre teens. My neighbor had one in a 900? Or something, but that was a bike I literally lookup to every time I saw parked out front. Good video, thanks for the time you took on this bike and video
I have a 1982 KZ750 CSR version of this bike. It was imported to the UK from the USA just a few years ago and the engine runs sweet. Overall fantastic original condition and a joy to ride.
Thank you, You have made me feel less crazy. , I have a 1980 KZ750-G . These issues are the story of my life!!! Yes, all the adjectives. My father said "Its almost always the switch or a loose connection." I too had a bad ground, but I never have only ONE cause to a problem. There is always something hiding that pops up occasionally cause a headache and then disappears before it can be found. I suspect the Key switch could also be the occasional gremlin that affects just enough to make one go WTF Now? and then gone
Glad you found the bug. We had a '79 kz750B and a 79 kz650C. When riding solo or up in the hills of northern CA, I preferred the 650. But for 2up or just around town cruising it was hard to beat the twin. It was a more relaxed riding position and was more fun at lower RPM's. Thank you for posting and taking me back 40 or so years in time.
This is shot in the dark, check the electrical portion of the ignition switch. Most of the time, water seeps through the key/ tumbler portion into the electrical area. The inside portion under the boot may be corroded either on the outside or on the inside of the switch.. Like I said, just a shot in the dark.
Yes definately, I have had this issue many times with old bikes. And if you have never done it before be wary of spings balls and terminals that will fly out the moment you seperate it. Best idea is to tale it apart in a large tub , so you dont loose any of the pieces.
@@motorcyclerewindAfter about 75,000 miles the ignition switch on my 2005 Sportster began to slip me the knife every now and then. I replaced it before it left me stranded. Disassemble and inspect every wiring harness connector for corrosion and broken wires. You have to give every wire a gentle pull to verify the integrity of the connection.
Great incisive patient diagnosis Mine had good electrickery, but had no torque with a 2/1 exhaust Much better acceleration with separate baffled megaphones.
@@motorcyclerewind the indicator light comes on when you press the brakes, but if your bulb blows, the indicator lamp will flash while braking. It's a feature Kawasaki put on the old KZ, lets you know when your brake light pops. Maybe try it by removing the bulb, and activating the brake switch? Glad you found the problem battery terminal, same thing happened to me once.
I had the same problem, I wiggled the loom connection that fed the rectifier and burst into life. By the way much prefer the old seats hinged, not modern bikes where you lift it off such a pain to put them back on!
Hey Eric, on my wife’s bike we had a similar issue. Turned out the negative battery cable was bad. Looks good on the outside but loosing connection where the eyelet was soldered to the cable. Resoldered eyelet, problem solved. Thanks for the great content!
I think I can see the camera bobbing with the bike. So, I think you have a GoPro on a stick and I think the stick gets automatically edited out, amazing! I like that bike too.
Sometimes the fuse holder contacts can be corroded. Measuring the voltage on a battery is not really telling you how good the battery is. A load test is the only way to see how good it is. I had one of these bikes back in the 80's and this one sounds a bit lame, are you sure it's running on both cylinders. You got to have a bad connection or wire somewhere. It does sound better than last time.
I had a 77 kz750 40 years ago, I had an issue with the ignition switch. I seen a spark when the extra keys would rub against the handle bars. Had a bad switch.
You could have avoided breaking the fuel tap, by undoing the two small philips screws and removing it for cleaning . Also clean the filter just above the bowl.
I am helping a friend curate his collection of 70 plus motorcycles. The number is the identifier. He has multiplies of the same motorcycles and we needed something easier than the vin, Here is a link to the first video we did on his collection. ruclips.net/video/4CX1UiVBFcI/видео.html
Are the rubber diaphragms in the top of the carbs in good condition? Above a certain number of revs, the bike will stall if those rubber diaphragms are damaged, punctured perished.
Bad Ground Strikes Again! - I would suggest always using the multimeter to verify you have zero resistance from the battery lead to the engine case. Test lights will still work even with some resistance. When reviving an old bike I check the full harness end to end for resistance on each trace. On my latest project, I found I had 14 Megaohms of resistance from my ground strap to my engine case! ruclips.net/video/8m4n7EZJsJg/видео.htmlsi=e0xP4xpZHZVcoKPN
Hey you were able to walk it home, pushed a CB900F home up a hill with flat when i was younger and stronger. Wouldn't like try that with a fat arse GS or HD.
No way! My worst was pushing a CB550 home about 5 miles(ironically on the road in this video) after losing the master link on the chain. Damn footage beat up my right leg. Never ride 'em, further than you want to push 'em!
Not sure that I would use an impact on a coil. The vibration of the impact may damage the coil. Maybe not but seems a bit excessive. Ask me how I know. 😂
One time one cylinder on my motorcycle wouldn't run right and I eventually found out that a mouse had gotten up into one of the pipes and built a nest. Weird stuff happens...
Good find! The "wiggle all the wires and see if it does anything weird" method has worked out for me a few times too lol. The years are not kind to these old wiring harnesses, but mechanically they just run forever.
Stay hydrated down there.
Sometimes you need to wiggle, wiggle, wiggle.🤣😂🤣 Definitely staying hydrated. Thanks for watching.
Guy I went to school with rode that same model early 80s to school collectable now poor seller back then so was the cbx remember left over sitting on the showroom at the local honda shop in slidell la for two or three years after they came out think you have an electrical glitch itll rear its head again if you dont find it first
Replace the ignition key with a known good switch and see if the problem disappears?
Maybe we will add switch to the list of parts since I am ordering a petcock. Thanks for watching
I had a '78 750B3 that did a frame-off restomod on, but I made significant improvements to the electrical system, including a blade style fuse box and electronic ignition. I re wired many of the connections because they were old and corroded out, including the one that gave you trouble in this video. But I still ahd an electrical gremlin that needed to be chased down now and again. Eventually, though, I got it sorted to the point that I felt comfortable taking it on longer rides. I spent many lovely hours on my precious KZ. They're super fun bikes. Enjoy the ride!
I look 👀 forward to spending some quality time with this motorcycle. Just need to sort the carbs and we should be golden. Thanks for watching.
Love this bike. Nostalgic from my pre teens. My neighbor had one in a 900? Or something, but that was a bike I literally lookup to every time I saw parked out front.
Good video, thanks for the time you took on this bike and video
This is such a great bike. Really enjoyed bringing it back to life. Thanks for watching.
Another great video. Gotta love a community that shares ideas and a RUclipsr that accepts suggestions! You’re awesome 👏😎
You called me a RUclipsr!!! 🤣 😂🤣I am too old for that term!!!👴🏻
So glad to see you have had some success getting it to run Eric, now those carbs need a really good seeing to and it will run sweeeeeeet 😎.
Agreed. Carbs are next on its list. Thanks for watching!
I have a 1982 KZ750 CSR version of this bike. It was imported to the UK from the USA just a few years ago and the engine runs sweet. Overall fantastic original condition and a joy to ride.
Those are awesome. Thanks so much for watching.
Thank you, You have made me feel less crazy. , I have a 1980 KZ750-G . These issues are the story of my life!!! Yes, all the adjectives. My father said "Its almost always the switch or a loose connection." I too had a bad ground, but I never have only ONE cause to a problem. There is always something hiding that pops up occasionally cause a headache and then disappears before it can be found. I suspect the Key switch could also be the occasional gremlin that affects just enough to make one go WTF Now? and then gone
Glad I could help with your mental health. 🤣😂🤣Thanks for watching.
Very nice Eric! Glad you found it, those can be so frustrating! That looks like a real good motorcycle designed in the classic style of street bikes.
It was making me crazy. So happy I found it. Thanks for watching.
I was sure it was blinker lens fluid but you proved me wrong, good on ya mate
Dang it! I forgot to check the blinker fluid. 🤣😂🤣Thanks for watching.
Glad you found the bug. We had a '79 kz750B and a 79 kz650C. When riding solo or up in the hills of northern CA, I preferred the 650. But for 2up or just around town cruising it was hard to beat the twin. It was a more relaxed riding position and was more fun at lower RPM's. Thank you for posting and taking me back 40 or so years in time.
Cant wait to put some more time on this seat. Sort the carbs then ride the wheels off. Thanks for watching
This is shot in the dark, check the electrical portion of the ignition switch. Most of the time, water seeps through the key/ tumbler portion into the electrical area. The inside portion under the boot may be corroded either on the outside or on the inside of the switch.. Like I said, just a shot in the dark.
Good idea. Thanks for sharing.
Yes definately, I have had this issue many times with old bikes. And if you have never done it before be wary of spings balls and terminals that will fly out the moment you seperate it. Best idea is to tale it apart in a large tub , so you dont loose any of the pieces.
@@motorcyclerewindAfter about 75,000 miles the ignition switch on my 2005 Sportster began to slip me the knife every now and then. I replaced it before it left me stranded.
Disassemble and inspect every wiring harness connector for corrosion and broken wires. You have to give every wire a gentle pull to verify the integrity of the connection.
13:44 You unleashed the Kraken! Now we're all done for.
Someone had to let it out!! 🤣😂🤣 Thanks for watching
Way to go Eric! Synch those carbs, check the timing and valves and you should be good to go. Definitely a keeper!
That’s the plan. Such a cool bike. Thanks for watching.
pro tip. use a socket on the battery terminal bolts , the phillips is just for starting the threads in the nut
Thanks for the tip and thanks for watching.
One of my favorite bikes...thanks
I am starting to see why. Thanks for watching
Love your channel, the intro is always a laugh, did you really ride away with a battery charger still connected? 😂😂😂
Yes I did! Wish I was smart enough to have planned it. Here is a link to the video. ruclips.net/video/dR9br3fI7Fc/видео.html
Definitely a fun bike when sorted.
Yes it will be!. Thanks for watching
Love your content.
Great incisive patient diagnosis Mine had good electrickery, but had no torque with a 2/1 exhaust Much better acceleration with separate baffled megaphones.
Thanks so much for sharing.
The red light on the dash, stop lamp indicator, is there because it flashes when your stop light bulb is blown.
It probably is blown. I don't remember if I looked to see if they worked. To be fair I cant remember what I had for breakfast! Thanks for watching
@@motorcyclerewind the indicator light comes on when you press the brakes, but if your bulb blows, the indicator lamp will flash while braking. It's a feature Kawasaki put on the old KZ, lets you know when your brake light pops. Maybe try it by removing the bulb, and activating the brake switch?
Glad you found the problem battery terminal, same thing happened to me once.
I had the same problem, I wiggled the loom connection that fed the rectifier and burst into life. By the way much prefer the old seats hinged, not modern bikes where you lift it off such a pain to put them back on!
Sometimes all you need is a good wiggle. Agree with you in the seats. Thanks for watching.
@9:05. Did you feel both head pipes to see if they were both warm? Sounds like only running on one cylinder.
I think it’s in the right carb. Especially at low rpm. Thanks for watching.
i was totally wrong and happy to say it but you nailed it in the end 2000 heads better than 1 nice one my mate 😜
I totally agree. Sometimes you're too close and cant see it. It was fun crow-sourcing the fix on this one. Thanks for watching!
I've always wondered what it would be like to belong to the smarter people club, I guess I'll never know🥴
Thanks for the video!!
I always wanted to be in that club too! 🤣😂 🤣
Hey Eric, on my wife’s bike we had a similar issue. Turned out the negative battery cable was bad. Looks good on the outside but loosing connection where the eyelet was soldered to the cable. Resoldered eyelet, problem solved. Thanks for the great content!
I think I can see the camera bobbing with the bike. So, I think you have a GoPro on a stick and I think the stick gets automatically edited out, amazing! I like that bike too.
You are correct. The riding footage is using a GoPro Max 360 camera that uses some witchcraft to work. It is pretty crazy! Thanks for watching
Little fine tuning now and it’s going to be perfect
Glad you found the bad connection!
Me too!!! Thanks for watching
I had a regulator rectifier problem that was similar to
Thanks for watching.
When you started it at about 1:30 into the video it seems like only 1 pot is firing. 1 cylinder is dead or intermittent at best.
Good ears. It sure was.
At 17:30 you can hear 2 pistons working.
Sounds so much better with two.
That was Fun! Thanks for sweating... I mean sharing! 😜
lol!!! Thanks for watching
Sometimes the fuse holder contacts can be corroded. Measuring the voltage on a battery is not really telling you how good the battery is. A load test is the only way to see how good it is. I had one of these bikes back in the 80's and this one sounds a bit lame, are you sure it's running on both cylinders. You got to have a bad connection or wire somewhere. It does sound better than last time.
Agreed must be a bad connection. Thanks for watching.
before the end i don’t think the side stand had electric fitted for this year of bike but maybe if did the side stand wire loose a wild guess ❤
That would be a great guess. Often overlooked.
I had a 77 kz750 40 years ago, I had an issue with the ignition switch. I seen a spark when the extra keys would rub against the handle bars. Had a bad switch.
Thats crazy! One way to determine if your switch is bad!!!
@@motorcyclerewind : I know. I was riding at night and you could see the keys arcing on the bars. Kept blowing the main fuse.
You could have avoided breaking the fuel tap, by undoing the two small philips screws and removing it for cleaning . Also clean the filter just above the bowl.
This petcock doesn't have the metal retaining plate with the two screws. I wish it did. Thanks for watching
When it stops, open the fuel filler cap and see if it restarts, you may have blocked breather
That’s a great idea. Thanks.
I like your ford truck! What is the #4 that you have on the headlight?
I am helping a friend curate his collection of 70 plus motorcycles. The number is the identifier. He has multiplies of the same motorcycles and we needed something easier than the vin, Here is a link to the first video we did on his collection. ruclips.net/video/4CX1UiVBFcI/видео.html
@@motorcyclerewind Thank you for the link. It turns out that I already watched it! lol
Are the rubber diaphragms in the top of the carbs in good condition? Above a certain number of revs, the bike will stall if those rubber diaphragms are damaged, punctured perished.
That’s a great point. Thanks for sharing.
Not a Kawasaki person , but old Honda twins would drop out one cylinder when the battery got low on charge
They sure do. Thanks for watching
Great work can u ship it to the uk pls 😂
That would be awesome. I would have to come with it and ride it around. Thanks for watching
Never ending aint it Eric?
If you mean the fun and joy of owning a vintage motorcycle, you would be right. 😂🤣😂Thanks for watching.
Intermittent short in the ignition perhaps.
Thats a great guess
I'm a owner of a 1980' KZ750 t same thing battery neg touching bottom if seat comes loose , the twins are Cool
So cool
you might want to secure the battery better to reduce fatique in the wires
Thats a good tip. Thanks for watching
Otta be interesting.
Did the stuff you guys said to do!!!
I vote for the switch.
That’s a good vote.
@@motorcyclerewind oh well turned out to be a ground issue.
Bad Ground Strikes Again! - I would suggest always using the multimeter to verify you have zero resistance from the battery lead to the engine case. Test lights will still work even with some resistance. When reviving an old bike I check the full harness end to end for resistance on each trace. On my latest project, I found I had 14 Megaohms of resistance from my ground strap to my engine case! ruclips.net/video/8m4n7EZJsJg/видео.htmlsi=e0xP4xpZHZVcoKPN
Thanks for sharing the link. I just subscribed. Look forward to digging into your videos.
@@motorcyclerewind Thanks!
Hey you were able to walk it home, pushed a CB900F home up a hill with flat when i was younger and stronger. Wouldn't like try that with a fat arse GS or HD.
No way! My worst was pushing a CB550 home about 5 miles(ironically on the road in this video) after losing the master link on the chain. Damn footage beat up my right leg. Never ride 'em, further than you want to push 'em!
@@motorcyclerewind Well, I was able to use the engine, clutch and idle it up the steep parts on the trot. 😀
The Turbonator wins again! 👍
I'll be back... on Thursday with another video!😂🤣😂 Thanks for watching
A nice bike with tons of miles left in it.
I agree. Thanks for watching
Now you just need a good exhaust on that bad boy.
That would be cool. Carbs are next! Thanks for watching
My guess the pb blaster in the ignition.swittchh was your problem
Maybe. Thanks for watching
Not sure that I would use an impact on a coil. The vibration of the impact may damage the coil. Maybe not but seems a bit excessive. Ask me how I know. 😂
LOL. Thanks for the tip
The 750 twins were never as popular as the 750 fours.
Agreed. Thanks for watching!
I just bought a 750B and started leaking fuel from the carbs. idk y
Probably a stuck float needle. It’s the most common cause.
One time one cylinder on my motorcycle wouldn't run right and I eventually found out that a mouse had gotten up into one of the pipes and built a nest. Weird stuff happens...
Thats crazy!!! Weird stuff does happen! Thanks for watching
Loose connection in the headlight shell. Total power out.Bad ignition switch.
Thanks for watching
Loosing power between the soleniod
Thats a good guess also. Thanks for watching
It runs not on 2 cil.sounds zo
Thanks for watching.
I'm sure you know ol
Thanks for watching
starter button
Would that make it lose complete power. Thanks for watching
haunted bike
I thought the previous owner put a Voodoo curse on it. Thanks for watching
It does not sound smooth. I remember mine running a lot smoother
Compared to the bucking bronco I rode it that last video.🤠🐎 It is much better.
@@motorcyclerewind When I said, I kind if meant it sounded like both cylinders were not firing right
These gremlins are the worst lol.
At least it lost all power again so we could sort it out. Thanks for watching.