TOPIC:

Hey guys, been creeping around the forum trying to absorb as much knowledge as possible (I've seen many threads similar to mine, so let me know if this is getting annoying to you gurus lol), but think it's time to pick some of the member's brains. I recently bought a 1980 kz650C from a guy who had bought it new in 1979, rode it until he had kids in 83 and then parked it. For 275 bucks (bought the 650 along with a 74 Kawi F7 and an 85 DR200 for a total of 800 bucks) I didn't mind the fact that it had sat for so long.

Got it home and first thing I did was take the carbs off to clean them. I took the bowls, carb tops, floats, float pins and needles out then dunked the rack in ammonia and hot water. A lot of the varnish broke free and a second bath in Simple Green (purple botle) with boiling water a tooth brush and elbow grease really got the grime off. During cleaning, the main idle adjuster (the screw that sits in between carbs 2 and 3) was turned in and out to ensure there was no seizing. I cleaned out the jets using copper wire and washed all the little tidbits with carb cleaner. Checked all passage ways with carb cleaner and then an air test (blew into passages to feel air coming out somewhere else). The only things I didn't take off adjust were mixture screws at the bottom of the carb bodys. But everything seemed gravy. I didn't have a battery by the time I was done cleaning the carbs and was excited to get it running so I decided to throw the carbs back on (i wish it was as painless as that sounds) and bump start it.

I attached the throttle cables to the carb and got the fuel line and the vacuum line from the petcock hooked up. The overflows from the carbs were starting to pour gas until i took a screwdriver and tapped the bottom of the bowls (read somewhere that after a cleaning the needles might just need to reseat themselves. and a tap can help). This made the carbs stop pouring gas. Took it to the top of my neighbors hill, put it in second gear, rolled, bumped it and voila! She puttered a little, came to life and then after she realized she was alive, raced the rpm's all the way to 3500, so after moving 100 feet under its own power i hit the kill switch. I figured that this was due to the main idle adjuster being out of whack from the cleaning. Parked it and bought a battery the next day.

So next day rolls around and I try to start it on the center stand. It fires up, putters and dies. Again, I figure this is due to main idle adjuster being off. Checked my fuel lines from the petcocks and there was fuel in there, then I checked the bowl drain plugs and gas was coming out of there. After numerous attempts of getting it to start, I sprayed a little ether into the air filter. The bike would turn over until it caught some vapors and would start up. I could keep the engine at 3.5k rpms with steady throttle and it wouldn't die out (mind you it would stay running long after the ether burned out), but let off the throttle from here and it would die. Also after holding the throttle open for a minute or two white smoke was coming from "around" the crankcase. (I read on here that could be gasoline in the oil). Spark plugs are all dry with only spark plug 4 having carbon deposits and still produces spark. So I turned it off and decided to come to you guys for advice.

TL;DR: My 1980 kz650c won't start up without ether. The carbs seem to be getting gas (checked via bowl drains) and the bowl overflows are working properly (they were pissing gas before i gave them a gentle tap from a screw driver). When I do start it with ether, it will eventually run on gas, but produces white smoke (it needs an oil change for sure, but would that really stop the bike from starting and running?) Also does anyone know what the factory setting for the main idle knob in between carbs 2&3 are. I have it 2 full turns in from where the knob starts applying pressure on the throttle. Any advice or guidance would be much appreciated, I felt like I did an extremely thorough job on the carbs, but I also read that idle jets could be why the bike won't stay running under 3-3.5k.

Much and many thanks,
Joinville

It sounds like you thoroughly cleaned the carbs. Keep in mind they are not the only variable that can cause poor or no running. What have you done as far as checking the ignition points and advancer? If the points are shot or the advancer is sticking the bike will run very poorly if it runs at all.

Also, did you put fresh fuel in it? Did you install a fuel filter to keep any nasty stuff that may be in the fuel tank from reaching the carbs? Ed

Thanks for the quick reply Ed! To start this reply, I will say that when the bike is running on gas (assuming that ether doesn't stick around for more than a minute) it sounds great, responds to throttle instantly and when held at constant throttle, purrs like a kitten, This is why I discounted it being the breaker points, but to be honest, I don't have the knowledge to make that kind of assessment accurately. I have yet to open the points cover, but was going to do so tonight and clean the contact points with a piece of paper if needed. As for fuel, when I bought the bike, the tank was bone dry and didn't have a speck of rust in so far as I could see. No fuel filter, but only fresh gas has been used. I may have come to the forums a little early in my efforts to get the bike running, but am new to motorcycles and figured a little guidance will go a long way

No eBay APP ID and/or Cert ID defined in Kunena configurationYou need to change the oil. The oil in there is more than 34 years old and is most likely so contaminated with moisture that its lubrication qualities are greatly reduced. Running the engine with that old oil can quickly ruin the engine.

You need to get a copy of the Kawasaki Service Manual and use it to perform all the maintenance that has been neglected since 1983. Be SURE to get the one that covers your bike's exact year and model as there are big differences between models and years. The list of years / models is on the back cover of the manual. I recommend you stop working on the bike until you get the manual as otherwise you may cause more harm than good. You can usually find the manuals on eBay - get the KAWASAKI manual, not Clymers, Haynes, etc. as it has the best information. The part number for the manual is 99924-1007-03; it will appear on the back cover. (See -
).

When you open the points cover you will see the points and the timing advancer they ride against. The timing advancer has a little cam on it that rides on the central shaft of the advancer. If it is properly lubed, that cam should easily rotate back and forth on the shaft with and you should feel moderate resistance caused by the springs attached to weights that engage the cam. Check that the cam moves freely. If it does not, the engine will not run right. That cam is supposed to be cleaned and lubed in accordance with the maintenance schedule contained in the Kawasaki Service Manual.

Also, take a look at the link below before doing more work on the bike. Pay special attention to the part about JIS vs Phillips screws. It will save you a big headache. Ed

LINK
www.kzrider.com/forum/2-engine/605639-ca...-valves-oh-my#759089

It usually takes me 2 to 3 deep cleanings to get a really nasty carb cleaned correctly. I would also do a complete tune up. Check valve clearances, points, change oil and filter, ect..

If you didn't take the mixture screws out do it and spray out the passages again. Bench set the slides and install a fuel filter. You can get one at your local bike shop.
Steve

If i am reading right you do not really clean the pilot circuit and removed the air screws.
You have to do this to get all the dirt out of the little bores and brass parts for a smooth idle.
Here some carb rebuilt tutorials

Sounds like the carbs are still dirty. complete disassembly and soaking everything is carb dip is needed.

Follow the VM carb guide and get new O-rings from cycleorings.com

Racing idle may result from air leaks in old cracked worn-out carb holders.

Good Fortune!

Overwhelmed by the amount of response guys, I am truly grateful. As a follow up to Ed's info on JIS vs Phillips head screws, SUPER USEFUL. I cleaned the points with some paper, but not much carbon was there in the first place. As to the thoroughness of my carb cleaning, I did not state it in my original post but all jets were removed, dipped in boiling water with simplegreen HD (the aluminum safe stuff) then cleaned out with a single strand of copper wire, shot through with carb cleaner and then compressed air. However, I did not take out the air mixture screws and will be taking the carbs off for another cleaning tomorrow night (thank you for all the guides on carb cleaning, will be treating them as divine mandates). I did change the oil and filter last night (oil was surprisingly not sludgy), checked the petcock for debris (it was amazingly clean, but I wiped down the screen regardless) and decided to try and start her for sh!ts and giggles. Put the choke on, hit the starter and it idled for two minutes at about 1200 rpm. When I tried to give it gas it would instantly cut out. So I'm assuming there's still residual crud floating around my carbs somewhere and cleaning them again will be my next step.

Things I will be ordering out of necessity/will be good to have (let me know if I miss anything):
-Kawasaki Service manual for kz650 C3 (guy said it was the 1980 model, but it has the dark blue with gold pinstriping, so I'm guessing it's actually a 79)
-Carb rebuild kit (need for the O-rings, would be wise to have backup jets)
-Carb boots for engine side of carbs (these appear to be in working shape but again, wise to have and switch out)
-Carb boots for intake side (these look haggard from muscling the carbs in and out)
-New air filer
-Compression gauge
-Inline fuel filter

Again gurus, thank you for the guidance and I'll be keeping you guys posted on what happens, maybe even throw some pictures up if my phone ever decides to turn back on.

Don't use a see-through paper fuel filter designed for cars. Gravity is not always enough to keep those flowing.

Joinville wrote: ..............
Things I will be ordering out of necessity/will be good to have (let me know if I miss anything):
-Kawasaki Service manual for kz650 C3 (guy said it was the 1980 model, but it has the dark blue with gold pinstriping, so I'm guessing it's actually a 79)
.....

WAIT! DON'T GUESS AT THE YEAR AND MODEL!

I hope you read this before ordering a manual. There are really serious differences between the various years and models of the KZ650, so you need to positively identify which year and model you have before ordering a manual. Fortunately, this is a VERY EASY thing to do. Take a look at the frame number stamped into the bike's steering neck. You may also see a white label still there. The serial number of the frame identifies exactly which year and model the bike is. If it is a KZ650C model the frame serial number will begin with "KZ650C-" followed by six more numbers. Use that frame number to look up the model year of the bike at models.kz650.info/index.htm .

So for example if the frame number is greater than KZ650C-022801 but less than KZ650C-033032 it is a 1979 KZ650-C3. You can also look up the engine number at the same site. That number is stamped into the engine just a bit forward of the oil filler hole. The frame number and engine number will not be the same number. Ed