86' ninja 600r...idle issues!

[timgeorgi]

I'm driving myself crazy with this bike. No matter what i do, i can't seem to get it running right. The main issue is the idle. While it does idle, it sounds as if it's going to die at any time. i've played with the mix screws, carb balance, and idle adjustments. I've completely taken apart and cleaned the carbs twice (Wanted to make sure all the passages were clean the second time!) The repair manual I have says 2 turns out for the mix screws, and idle between 1000 and 1100. At that speed, there is no way that I have found to get a smooth idle. sounds very bad (like rattling gears). I need a step by step guide to properly adjusting the idle mix screws and carb balancing. I have the mercury tool to balance the carbs, but the engine seems to sound worse when the tool indicates the carbs are balanced. The top end has been completely redone (Valves and piston rings). Compression is good. If anyone can walk me through this, i would be so happy! The bike is totally stock. I just want it to run right! If anyone can provide factory specs, that would be a help to. BTW, does the octane level of the fuel matter....I have herd that premium gas makes these bikes run poorly, but my repair manual says to only use premium...does it matter?? I tried both and didn't notice much of a difference. Thanks in advance for any help!

[QKENUF4U]

fuel wont matter unless its got water in it. a factory service manual will tell you everything you need to know

[Lawn Masters]

How is your fuel filter? clean or no?

[timgeorgi]

Filter is new...can anyone confirm the factory spec for the pilot screws. i have them at 2 turns now.

[elr658]

Valve adjustment set to loose side of tolerance FIRST.

[timgeorgi]

still working on this one...what do you mean FIRST?? Check the valves first then tackle the carbs? When I put the head back togeather I set the clearances to about the middle. Should I go back and adjust them to the loose side? Please clarify...also, if anyone has the FACTORY shop manual, can you please let me know the spec on the pilot screws. I've checked 3 places and gotten 3 answers . Really want to get it running right. Thanks!

[zx600c]

Well I was told it is 2 turns once LIGHTLY seated man. Hope this helps ya.

[sliver240]

You'll probably be better off setting the screws at 2 1/2 turns out. A little richer is better than lean. Factory settings are to lean for emissions purposes.

[timgeorgi]

I've tried 2.5 turns as well...just can't get a steady idle. I'm probably gonna take it in and have it looked at by a professional. i'm getting really frustrated with this. just doesn't want to run right

[itjstagame]

Where does it comfortably idle? Mine is old and tired and I have the idle set at around 1300rpm I think, lower than that and it bogs slightly and sometimes when revving down and clutching in it'd stall.

[wiredgeorge]

Your tach isn't accurate at idle. If you want to set your idle using a tach, use a stand alone unit. Turn the idle up till it is smooth... perhaps almost to 1500 rpm. Most older bikes have an idle spec at around 1000 rpm and don't like to idle at that speed by their tach.

The comment regarding valves... How did you set valve clearances? Once the head is installed and the cam caps torqued, the clearances should be checked. This step needs to come FIRST in any tune up procedure. Tight valves with lack of clearance can hold the valves open and you will lose compression and the carbs will never tune properly.

If you have the proper valve clearance and have sync'd the carbs, I note you failed to mention float level. The carbs with improper float levels (wrong amount of gas in bowl) will NEVER tune properly. Set the float level first. You also failed to mention whether you are using aftermarket, individual air filters (pods) or the stock airbox. The use of aftermarket filters without properly rejetting the pilot system will ensure the bike won't idle as it should.

[itjstagame]

If you have the proper valve clearance and have sync'd the carbs, I note you failed to mention float level. The carbs with improper float levels (wrong amount of gas in bowl) will NEVER tune properly. Set the float level first. You also failed to mention whether you are using aftermarket, individual air filters (pods) or the stock airbox. The use of aftermarket filters without properly rejetting the pilot system will ensure the bike won't idle as it should.

How do you set float levels?

[wiredgeorge]

This is explained in a Kaw Factory Service Manual or Clymer Manual for your bike. There are a couple different ways and different specs for each carb type and without knowing your bike type, I would prefer not to type out each method... Start a separate thread for your bike if you need to or would like to know how to adjust float levels.

[timgeorgi]

OK...to answer a few questions...Yes, I have checked the float bowl. The spec I have is +-1MM above the lip of the float bowl. That has been adjusted. Second, the valve clearances were checked after re-assembly...I set them to the middle of the spec listed in my repair manual. As far as where the bike idles, it will not stall with the factory tach reading about 1400, BUT it sounds horrible. not even close to a "smooth" idle. The bike is totally stock...this includes the airbox. I still havn't taken the bike in do the service place yet...as there has been a lot of recent activity on this thread. If anyone else has ANY ideas, please feel free to throw them out there. Any help would be great!

[timgeorgi]

Still working on this...after rechecking everything, i'm thinking my problem is in the carbs. After rechecking the float levels, i have noticed that i seem to get different readings each time i attempt to measure the level. Sometimes they fill right up to where they are supposed to, other times they seem to fill very slowly, and only about half way up the bowl. With the float bowls off, gas pours freely out the float valve, and none seem to be sticking. I cleaned them anyway. The mothod i'm using is to have the carbs off the bike (But clamped to a level surface!). I have a temp fuel tank above the carbs, the same setup as the stock tank (Gravity feed). I have attached a clear piece of tube to the drain on any given carb. This tube loops under the carb and back up alonge side. It's my understanding that the float level should be +-1 MM from the seam where the float bowl meets the carb. Once the tube is in place, i crack open the drain screw and wait for it to level out. Sometimes the gas comes right out and up to the seam, other times it just trickles and only fills to about half the level it should. Is it possible there is a vent somewhere that is clogged so that the air pressure in the bowl can't escape and won't let fuel in? Is there a better way to set the float level? Thanks!

[QKENUF4U]

i wont get into the whole float level/fuel level deal but sounds like you might be onto something. float/needle might be hanging up for some god-only-knows reason. (pin thru float bent ? float bent and rubbing on bowl inside ?)
good luck