Cranks no start

[bonaduce]

I know a vague title, I haven't posted in a long time since I haven't had any issues with my '03 600. This morning she started up fine and was warming up, went inside to get my gear on and say goodbye to the family, about 5-7 minutes, and I hear the bike stop running. Now the engine turns over but sounds like no spark. Just looking for ideas on where to start looking first, coils or kill switch?
thank you for any advice

dan

[steves]

You're getting fuel into the bowls? If it's been running fine for a while and all the sudden doesn't.... I'm thinking it's a fueling problem. Check the petcock first. Then the battery.

When you say "no spark" you mean "no flashy light from the sparkplug" or you mean it won't catch?

[92xjunker]

If it's the petcock, try starting on prime.

[bonaduce]

update, when I got home from work the kat started right up with 1/2 choke. I could hear a popping (detonation) sound from under the tank. Moved choke back to 1/4 and sound went away and all was normal again. Rode bike to work this am, again detonation, but again went away, however under slight throttle she chugs, almost like a cylinder isn't there. I am now leaning towards time to clean the carbs again?

thanks for any advice

dan

[RobertTravis]

Never hurts to thoroughly clean them...plus, add a fuel filter to keep chunx out

[steves]

Yeah, when in doubt clean the carbs...unfortunately

[bonaduce]

update, After draining the tank and cleaning the carbs, reassembly, I now have no spark what so ever. I know from working on cars that it is possible to have all coils give up the ghost at the same time, but the odds of that are low. Should I be looking for something else. I did check the ignition fuse and that was good, and will be going through the diagnostic tree in the online manual I downloaded, today. Just wondering if I am missing something.

thanks for the advice
dan

[92xjunker]

Sometimes you need a little starting fluid to get things flowing after carb work.

[bonaduce]

update: thanks 92xjunker, I thought that as well but to no avail, even that didn't provide a pop.
-tested both coils: cylinder 1/4 coil gave me primary of 2.7 and secondary of 35.6, cylinder 2/3 primary of 2.7 and secondary of 36.83 those are in spec.
-Start, kill, clutch and neutral all passed continuity.
-Kickstand in up position reads 177.8, and in down reads 180, by the manual this should fail
-tested the diode related to kickstand switch across d-e terminals at times I got ol and other time got 13.59, when 12 volts applied to c terminal diode clicks and I get a reading of .08, not sure id diode fails or not.

thanks for advice

dan

ps went back out to the garage this afternoon and decided to clean some connections and change the plugs while I was at it, sprayed with starting fluid and got it to run. So I decided to put the tank on, went through prime, and she purred to life, ran for 3-4 minutes and stalled again, back to square one. Remove tank again, sprayed fluid into the feed pipe and she wanted to start, So lets revisit the fuel, is there a diagram for how the petcock works?

dan

[RobertTravis]

is there a diagram for how the petcock works?

http://katriders.com/wiki/index.php?title=Petcock

[92xjunker]

Pull the fuel hose, should flow freely in prime. Install a vac hose, put in run and reserve, apply vac it should flow as long as there is a vac applied. Diaphragm may be stiff.

[bonaduce]

update, fuel flows while on prime, steady stream. Applied vacuum to the back of the petcock, fuel flows on reserve, may not have enough gas to flow when in on. Was able to get it to start and run while on reserve, was running nice till about 4-5 minutes than started to sputter and pop again, give throttle and could keep it running but still sounds like a cylinder skip, finally stalled and unable to restart. It is almost like when the engine gets hot the problems begin, when it cools down, I can get it to start again.

dan

[92xjunker]

You didn't run it that long without a fan did you? It could and will over heat If the carbs aren't running properly. You should have a good fan blowing at the head and oil cooler while servicing that long.

[bonaduce]

I did not have a fan blowing any air at it. will definitely set that up tomorrow when I get another chance to work on it.

dan

[bonaduce]

update, got home from work and checked a few things on the bike that the old Suzuki dealer parts guy suggested. Vacuum hose off of carb 4 has no cracks, applied vacuum to said hose while attached and it held at 60 lbs. I explained it stalling issue and he said to check the gas gap after it stalled, unfortunately never got that far, as the bike "backfired" through the exhaust and than wouldn't remain running more than 10-15 seconds. (see attached videos for reference of how it is running now). I installed a new fuel filter on Monday, correct me if I am wrong but shouldn't that be full of gas when in prime, because it isn't. Beginning to lose my mind.

https://youtu.be/sVOoeQyYt1o

https://youtu.be/_Jf6qo8qKW8

thanks for helping maintain sanity, and sorry for shaky video's
dan