1990 600 Not Starting

[tecguy]

I' m pretty new at riding, and purchased a 1990 kat 600 about 2 weeks ago. I test drove it and dove it around for about a week. everything was fine. then one day when it was cold it would not start. I figured the battey was weak so I push started it. Everything was fine untill two days later. I drove it about two hours out of town and parked it. It was about 6 hours later i came back to the bike to leave when it would not start. it was about 70 degrees outside. The bike would not even turn over. I figured it was the battey again so I jumped the bike. nothing happend. I unhocked the cables and kept trying. eventually the bike started to turn over. I had the choke wide open and was giving it a lot of gas. I figure i flooded the engine but eventually it started and did not idle. it ran for like ten mins before cutting back off, not to start again. It also ran very rough.

(sorry for the long post) The next day I drove back to the bike in warm weather to try to start it. It cranked right up, but would not idle and was still running rough. i drove it like ten feet to a gas station and could not get it started again. i eventually took a trailer there and brought it back.

the previous owner said he had the carbs cleaned and synced. i changed the fuel filter, oil and would like to change the spark plugs but cant find the right socket. (anyone know what size it takes/ tried 3/4too big 5/8too small 11/16too small) any other sugestions that might resolve my problem? currently it turns over but does not ignight.

[kevin2502000]

18mm deep well socket and you have to havy long needle nosed pliers to pluck them out. If you flooded it bad enough the plugs are probably toast, good place to start.

[tecguy]

18mm deep is too big to fit tin the hole. any other suggestions?

[tone]

18mm thin walled plug socket, & i agree with the above the plugs are probably dead & i'll add it could also be carb rebuild time as you dont know the quality of the previous guys work

[Kfreak]

18mm thin walled plug socket, & i agree with the above the plugs are probably dead & i'll add it could also be carb rebuild time as you dont know the quality of the previous guys work

You got crap in your tank. RUST!

[Slofuze]

Two things come to mind..... your battery is toast (check the level) since no charging in the world will help it keep a charge. Second.... you fouled the plugs to the point that if there's fuel in the cylinders from trying to start it, even changing the plugs won't help for long and you may end up dropping a cylinder or two just to clean them out ..... and, unfortunately, re-fouling your plugs. It happened to me once and that's what I found the problem to be.

[DumbLuck]

no OEM tool kit with the bike? if not, order one from TheCyberPoet. they include the plug wrench which fits nicely down da hole

[tecguy]

thanks, all, yeah, after many trips to my local auto store, I finally found a thin wall socket and got the plugs out. they were toast. they were still wet and reaked of gas three days after the last start attempt. I blew out the cylinders with air and hopes to replace the plugs tommrow. yeah, i agree def need to up that battery to a higher cold crank amp one. thanks all.

[tecguy]

I swapped out the plugs today. It fired right up. it still had problems idleing and did idle for about 10 mins with choke wide open, then cut off, back to square one. it will not start. it may be dirty jets? any more suggestions?

[kevin2502000]

You probably fouled those plugs as well. You probably need to clean the carbs.

[md86]

Yeah , don't choke it for 10 minutes . CHoke it to get it running , and enough to keep it a 2k rpm's for MAYBE a minute , then back it off and use a little throttle to keep it running if need be .
Also , "wouldn't even turn over" deserves more exploring . Was it "just" a battery ? No need for massive CCA's if it's in good shape . Hell , I use the $30 JCW battery , and it works just fine . Been in there for like 3 years , too .

[tecguy]

yeah, i figured out that it was a bad spark plug wire on cyl #4. I replaced the solonoid and not it starts just fine with no choke and runs a lot smoother. but that isn't the only problem. it still dies after a couple of mins. it revs up to 3k then drops to 2k without any throttle. about 15 seconds later it drops to idle between 1.5k and 750. it stays there for about 3-4 mins before dropping lower to cut off. I can usually save it by giving it trottle but never idles again without any choke. Then I find myself waiting about 15-20 mins before it will start. and starts the process all over. I found a vac hose missing from the petcock to carb #4 and hooked it up but that really did nothing. I am going to take it into the shop on monday to get the carbs cleaned and checked but really would not like to spend 120 or more to have everything done especially since they were just cleaned and synced. I have been playing around with the idle adjustment screw to see the engine live a bit longer or shorter, depending but still the same outcome. does anyone have a diagram of vac hose routing from the tank and carbs for a 90 600? I want to be sure i have the hoses right.

[Kfreak]

There is only one vac line, unless you have a Cali model.

[tecguy]

yeah, i want to be sure it's in the right spot. the other line is a vent I know. When I bought it though, both lines were ran as if vents.

[Kfreak]

The vac line runs from #4 carb to the petcock. The two lines from the tank run along the sides of the air filter and hang down above the swing arm.

And that's all folks.