Started yesterday, won't start today...desperate....

[femmekat]

So last weekend the bike developed a problem while idling, gets stuck at 4-5,000 rpms at a stop, or idles down from 2,000 rpms to nothing and then stalls... So have to give it throttle at a stop or leave the choke open..

So pulled it apart with a buddy, one of the rubber boots was off a carb intake, didn't do much to it as we didn't have the tools/appropriate location to work on it. Put it back together, then I tried to start it on Monday and it wouldn't start. Wouldn't even catch... (this was not a problem previously before the bike was apart...)

Took the bike to work on it yesterday, replaced the spark plugs, charged the battery, sprayed carb clean in it. Started up fine yesterday, but still having the idling problem. Rode it home about 60 miles, started up fine after fueling up, etc. and parked it overnight. Went to start it up today to take it up to a mechanic to have the carbs pulled apart and cleaned, and now it won't start again. Battery sounds strong, but turned over once when I first started it, then hasn't since. What the hell is wrong with it? Any tips on getting it started up so I can get it to the shop?

Lauren

[gazoo]

if your're taking it to the shop then just spray a LITTLE bit of starting fluid into the airbox and it'll start . let it warm up a bit and drop it off at the shop . good luck .

[Great ATuin]

Mine had a similar symptoms. Idles around 5000 for 5 seconds, than slow down to 2000 for 5 secs and slowly dies. Maybe it's the same problem.

Check how air ducts sit on the carbs on the bottom side. Mine used to sit fine on the carbs, but when i tighten the airbox to the frame, ducts slip off on the bottom side just a little bit, but enough to make the problem.

Tho, no idea about the starting problem.

[Kreylyn]

Sounds like the pilot jets are dirty, and restricting gas flow... Pilot jets are the fuel delivery for Idle and starts.

No gas, no start, no go...

Once running, "bumping" the throttle will keep the bike running because your adding fuel to the mix slightly each time from the main jets...

It takes a moment for gas to make it's way from the carbs to the engine, and to be used up. An example... If you had an engine with no gas to the carbs, but just opened up the butterflys and squirted a bit of gas into them, it would run for just a brief moment... as it starts to die, if you squirt a little more.. it will idle again for a short time... then start to die... you can do this indefinately.

That is basically what your doing now when you "blip" the throttle... only your using your main jets to squirt the gas in so that it will idle for a moment.

The fix to your problem is... pull the carbs off, and clean them fully paying special attention to your pilot jets.

This link will cover the details of everything you need to do... it's actually pretty simple to follow these instructions and the printable PDF linked has pictures so you can see exactly what it's talking about.

http://katriders.com/vb/showthread.php?t=63344

Krey

[scottynoface]

Pilot jets and vacuum leak from the airbox boots. Carb clean and fit the airbox properly

[femmekat]

So...finally got it to start...

Took it to the shop to clean the carbs...and they were pristine. The mechanic took a good look at them, and said no need to clean them, that's not the problem...

The bike has been completely apart 3 times in the last week, and I know for sure that the airbox is fitted properly... I have had my hands in there pushing the boots on while someone else tightens them 3 times now, and I know they're on snug....

Sooo.... both the mechanic and I are stumped... It wants to idle super high, and seems to get stuck, or take a long time to come down if at all...

Has nothing to do with the idle adjustment screw...

What next? I'm about ready to offload this bike... I want to ride so bad and its been one thing after another...

[Kfreak]

I have gone thru this. You can put the carb boots on many times and tighten them up. If you over tighten the clamps they are scrap after that. They get bent out of shape, plus the boots get distorted. They slip off on the underside. I changed the boots with some good used boots plus put new clamps on. I then put the airbox on the carb's before I mounted the carb's onto the motor. MD has said this many, many times to do this because you are guarenteed to get a good seal. Check the slides for any tears in the diaphrams and make sure the "O" rings are in place for the vacuum ports if your bike has them.

[femmekat]

If this ends up being the problem...where would I get boots and clamps? Would they need to be ordered through a dealer? It is a 1991 600. Any other possibilities for the cause of the problem?

[Kfreak]

Anyone on kR may have a good used set of boots. That is where I found mine. You can get them from the dealer but they are around $20.00 apiece. The clamps, I suggest you get them from the dealer. The clamps for the airbox to the carb's are the ones that always get over tightened and bent out of shape. The key is not to crank the crap out of them like everyone does thinking they are getting a good seal. Another area to look at is the "O" rings on the intake manifolds. Or possibly a cracked intake manifold or manifolds. It is frustrating. I finally left my fairings off until I found the problems.

[JinxXx0085]

IDK if this is even relevant at all. I'm far from an expert... I recently had a problem with my kat where itd rev up to 5500 rpm and stay there for most of the time. It turns out I had a sticky choke cable. It was keeping choke open when it should have been closed.
So... The point is... Maybe take a look to see if the choke does open and close normally as it should.

[Kfreak]

It is possibility to rule out.

[femmekat]

Thanks for the pointers Kfreak, the day after this issue started, my buddy did notice upon inspection that one of the boots wasn't completely attached (which we resituated then tightened)...and looks somewhat misshapen around the seal... Maybe its just toasted, and even though we've had the bike apart then back together multiple times, it has reached the end of its life and needs replacing... Will definitely check it out... Am contemplating ordering one through the dealer and replacing the likely suspect while I try to find a used set as well.....

Never thought my first bike would require so much learning/wrenching so quick... I'm on my 10th ride (ever) and have had a million things break, and already had the bike apart like 5 times in 4 weeks, sheesh... I sure am learning a lot though

[plyhockey3]

I know they say they arent dirty but mine did exactly the same thing. I just put some sea foam in the tank and cleared it up. I would pull up to a stop and the idle would be at about 3- 4k then if I let off the clutch just a little it would idle down and usually die. Use a little over an ounce per gallon of gas. Its $10 at checker or auto zone.

[femmekat]

Called the dealer and the boots new are only $11 apeice, so I ordered them and new clamps... Hopefully that's the fix! Will follow your advice about mounting steps to guarantee proper seal...

[Kreylyn]

Called the dealer and the boots new are only $11 apeice, so I ordered them and new clamps... Hopefully that's the fix! Will follow your advice about mounting steps to guarantee proper seal...

Simple test to see if part of the issue is a vacuum leak, such as bad boots.

When running, spray around the boots or connections with rubbing alchohol in a spritzer bottle, or basic spray bottle. If the revs pic up, you have a leak. No effect, no leak.

Krey