[Kreylyn]

Ok, I've replaced the intake manifold gaskets and the bike runs a LOT better. I was actually able to take it out for a ride.

When it was cold I had it idling sweet at 1200 and then I took it out for a ride. By the time I got back my idle was around 3000 again. The throttle is a lot more consistent now and the bike seems much happier but I still end up with a high idle.

I've also started to try and use the choke and I'm having issues when I do use it. If I use the choke I don't get full return when I try and turn the choke off. I've taken the pistons out and cleaned them up as well as the cylinders then lubed everything with WD40 as I've see suggested here on the forums. They seemed to work well but when I put the choke rail back on I have to manually push the pistons back in the last 15% to get the choke all the way off.

I'm going to get the bike started and spray some more carb cleaner around the boots and air box to make sure I don't have any vaccume leaks. If I do I'll work on getting those fixed.

Also, I want to make sure I understand carb tuning properly. If I lower the c-clip which raises the needle that will make the mixture richer right ? If I turn the A/F screw in clockwise that makes it richer and when I turn it out counter-clockwise it makes the mixture leaner right ?

Set the idle when warm, then don't mess with it. use the choke to start and warm the bike for the first minute or so, maybe less depending on weather.

If your choke will not fully reset, then something is wrong. Remove the rail, check the individuals pistons. If they are fine, then put the rail back on. If that is the only change, and it's binding.... check to make sure your rail isn't bent, and it's properly installed. If no binding then, hook the cable up and make sure that works. If binding at this point, check/clean/replace the choke cable. This needs to be fixed, or it's gonna cause lots of issues.

Moving the E-clip down from the top towards the pointy end will richen the mixtures for the main.

Turning the A/F screws out (counter clock wise) will richen the pilot mixture.

Krey

[kevin2502000]

Set the idle when warm, then don't mess with it. use the choke to start and warm the bike for the first minute or so, maybe less depending on weather.

If your choke will not fully reset, then something is wrong. Remove the rail, check the individuals pistons. If they are fine, then put the rail back on. If that is the only change, and it's binding.... check to make sure your rail isn't bent, and it's properly installed. If no binding then, hook the cable up and make sure that works. If binding at this point, check/clean/replace the choke cable. This needs to be fixed, or it's gonna cause lots of issues.

Moving the E-clip down from the top towards the pointy end will richen the mixtures for the main.

Turning the A/F screws out (counter clock wise) will richen the pilot mixture.

Krey

I bet you have something bent or one of those clips are messed up, I had a similar problem with mine at one time and that was it. The choke rail is what I am referring to.

[Asmodeous]

Ok, just checked the bike and the choke didn't disengage at all when I backed off the lever at the handle bar. It seems like every time I clean and lube the choke setup it works well and then the lube dries out. After that it seems to kinda stick. Is there suppose to be some sort of retaining system for the choke cable or does it just sit in that cast section of the carb and the spring is suppose to hold it in and provide the return tension ? It seems like the spring that I have in there is a bit warn out/not straight. I may need a new/stronger spring, the one in there is really wimpy. Also, I only have 2 of those black clips instead of 3 that guide/retain the choke rail, I imagine that could cause some problems ?

So I should use the choke to get it started and then once the bike is warm I set the idle to 1200 rpm ? After that I balance the carbs with some carb sticks or a vacuum gauge ? If I do it with a vacuum gauge can I just hook up 4 gauges at once and get them all even ?

I've read and reread the Suzuki shop manual and it just seems to not include certain things like adjusting the A/F screw...

[Kreylyn]

Ok, just checked the bike and the choke didn't disengage at all when I backed off the lever at the handle bar. It seems like every time I clean and lube the choke setup it works well and then the lube dries out. After that it seems to kinda stick. Is there suppose to be some sort of retaining system for the choke cable or does it just sit in that cast section of the carb and the spring is suppose to hold it in and provide the return tension ? It seems like the spring that I have in there is a bit warn out/not straight. I may need a new/stronger spring, the one in there is really wimpy. Also, I only have 2 of those black clips instead of 3 that guide/retain the choke rail, I imagine that could cause some problems ?

Each of the choke pistons should have a spring in them to provide the force to close them. With the choke rail off, check each to see if they will return to position when pulled out. If not, fix that issue.

The spring on the cable just helps to keep the cable seated, there is no retaining system. That spring is not what provides the return tension for the pistons though, they are in each piston. That spring just keeps the cable tight and in place.

So I should use the choke to get it started and then once the bike is warm I set the idle to 1200 rpm ? After that I balance the carbs with some carb sticks or a vacuum gauge ? If I do it with a vacuum gauge can I just hook up 4 gauges at once and get them all even ?

I've read and reread the Suzuki shop manual and it just seems to not include certain things like adjusting the A/F screw...

Use choke to get the bike started, and for a short time (1 min or so) til it will run without choke. It will probably still be sluggish/low idle for a few minutes until it fully warms up depending on weather. Ride the bike for 10-15 mins to fully warm up the engine. If your going to set the idel, then go for 1100+/- 100 rpms... adjusting when it is warm.

If you have not synced the carbs yet, don't bother setting the idle yet. Your going to change that.

To sync the carbs, set the idle up to 1700 rpms, sync carbs 1-2. Get them to match. As you sync them, you may need to further adjust the idle cable to keep the idle at 1700 rpms.

Once you have 1-2 synced, then you switch to 3-4 and sync them. Again, may need to adjust the idle to keep it at 1700 rpms.

Once you have 1-2 synced, and then 3-4 synced... you sync both sets together with the center adjustment screw. You can connect either single carb from one set to either single carb of the other set to bring all 4 in sync at this point (remember, both sets are synced with each other so it doesn't matter...)

Everyone is focused on "doing all 4 at one time"... well, you are doing all 4 at one time. You have 3 adjustment screws... you HAVE to adjust each screw seperately anyways.... so you only need 2 hookups. Do 2, then 2, then sync all 4 together.

Krey

[bobthebiker]

carb synchronizing will make your bikes idle very different. dont forget to synchronize them. it'll help if your idle hangs when you rev the motor too. I've been there and done that on a few bikes.

[Philskat]

Just joined the forum and am liking what i am seeing. Just ordered a repair manual for my newly aquired basket case 90 600 kat. My first of many questions im sure is, how to get that brass plug out that covers the af screw because i cleaned the carbs last night and noticed that 3 plugs are missing and one is there and i want to pull it so i can clean it because the rest were pretty nasty. thanks in advance Philip

[nealy212]

welcome to kr bro,,ur gonna have to get a small drill bit and drill the cap out, its thin so be very carful not to push to hard and it drive through into the screw.

[kevin2502000]

Ok, just checked the bike and the choke didn't disengage at all when I backed off the lever at the handle bar. It seems like every time I clean and lube the choke setup it works well and then the lube dries out. After that it seems to kinda stick. Is there suppose to be some sort of retaining system for the choke cable or does it just sit in that cast section of the carb and the spring is suppose to hold it in and provide the return tension ? It seems like the spring that I have in there is a bit warn out/not straight. I may need a new/stronger spring, the one in there is really wimpy. Also, I only have 2 of those black clips instead of 3 that guide/retain the choke rail, I imagine that could cause some problems ?

So I should use the choke to get it started and then once the bike is warm I set the idle to 1200 rpm ? After that I balance the carbs with some carb sticks or a vacuum gauge ? If I do it with a vacuum gauge can I just hook up 4 gauges at once and get them all even ?

I've read and reread the Suzuki shop manual and it just seems to not include certain things like adjusting the A/F screw...

Are you sure you don't have a bad cable? If it is binding now, unhook the cable and see if it slides freely then.

[Philskat]

welcome to kr bro,,ur gonna have to get a small drill bit and drill the cap out, its thin so be very carful not to push to hard and it drive through into the screw.

Thanks i will do it tomorrow

[Asmodeous]

I'll test the choke cable/rail tomorrow. I went out with the girlfriend tonight instead of working on my bike.

I bought a vacuum gauge today since my dad's manometer only goes to 1350 rpm. What PSI/Bar measurement should I have the carbs for the master carb and then synch all the other carbs to ? Should I do that at 1700 RPM as well ?

Thanks for all the help so far guys. I really appreciate the advice and support... I know a lot of these questions have been asked and answered before.

[Kreylyn]

I bought a vacuum gauge today since my dad's manometer only goes to 1350 rpm. What PSI/Bar measurement should I have the carbs for the master carb and then synch all the other carbs to ? Should I do that at 1700 RPM as well ?

Thanks for all the help so far guys. I really appreciate the advice and support... I know a lot of these questions have been asked and answered before.

There isn't a "set" specification for the vacuum for you to set it that way. There also isn't a "master" carb.

The process of syncing the carbs is to make all 4 carbs balanced and pulling the same vacuum across each. You want to be making adjustments to compensate for variances between each cylinder setup and each carb body.

Those variances can be huge, and the bike does not need to have a specific amount of vacuum for it to work correctly... just balanced between all 4 carbs for what it does have. (super tech guys; Yeah, I super simplified that... no need to confuse with extream details.. )

Using a tool that shows the vacuum levels for 2 carbs at a time, you adjust until you have even vacuum between the 2. This is what we call synced.

Your bike has 4 carbs, each of which are paired up into 2 "sets' of carbs. 1-2 and 3-4. The grouping for this purpose is based upon the 3 adjustment screws on the butterflys. There is an adjustment between 1-2. This only adjusts between those 2 carbs, so we will call that set 1. By adjusting that screw, your tweaking the butterfly flaps between each. One is being opened more, the other is being closed more. You continue to adjust this screw until you get the butterflys positioned to make both carbs pulling the same vacuum, or ... "synced". Once you have those set... they will stay synced and now work as a set.

Next you do set 2 by adjusting the screw between them. Again, this only adjusts those 2 carbs, and will not directly effect set 1. Once set 2 is balanced..... move on.

At this point... you now have set 1 balanced, and set 2 balanced... but not to each other. This is where you choose one carb from each set to hook up, and then using the center adjustment screw... sync all 4 together.

You will always be working with a pair... it's nearly impossible to do a good sync with working with only 1 carb at a time, because your adjustments effect 2 carbs at a time.

Krey

[Asmodeous]

Ok, got the choke working perfectly now. Good call on the bent choke rail, it was not exactly flat but the real problem was that it was bent up and down as well. That only caused a minor hang up. The major problem was interference from my fuel line on the choke rail.

I've set my AF screws to 2 3/4 turns and have my needles at the 2nd position from the top. Currently the bike starts quite easily. Idle gets faster as it warms. Once it is warm, if I rev it, the idle goes to 3000 and doesn't really come back down unless I adjust the idle screw. The bike will almost die or die unless I crank the idle screw back up a bit. If I cover the air box opening with my hand the idle goes up higher. I assume this means the idle screw needs to be unscrewed some more ?

Any tuning tips to get the bike to idle right or should I just try to synch the carbs as is ?

[Kreylyn]

Ok, got the choke working perfectly now. Good call on the bent choke rail, it was not exactly flat but the real problem was that it was bent up and down as well. That only caused a minor hang up. The major problem was interference from my fuel line on the choke rail.

I've set my AF screws to 2 3/4 turns and have my needles at the 2nd position from the top. Currently the bike starts quite easily. Idle gets faster as it warms. Once it is warm, if I rev it, the idle goes to 3000 and doesn't really come back down unless I adjust the idle screw. The bike will almost die or die unless I crank the idle screw back up a bit. If I cover the air box opening with my hand the idle goes up higher. I assume this means the idle screw needs to be unscrewed some more ?

Any tuning tips to get the bike to idle right or should I just try to synch the carbs as is ?

When you say starts easily, is this with choke on... or even with choke off?

Sounds like some lean conditions are presenting themselves with the hanging idle. But... if the sync is way out, that could cause some issues.

If you can get close to 2k, try to sync the carbs. Adjust as nessasary. Idealy, you want to do the final sync for the carbs right at 1700 rpms. Getting them somewhat closer though might help your issue.

Krey

[nealy212]

When you say starts easily, is this with choke on... or even with choke off?

Sounds like some lean conditions are presenting themselves with the hanging idle. But... if the sync is way out, that could cause some issues.

If you can get close to 2k, try to sync the carbs. Adjust as nessasary. Idealy, you want to do the final sync for the carbs right at 1700 rpms. Getting them somewhat closer though might help your issue.

Krey

yeah then i would be thnking about a possible leak or floats or a/f, but just fyi,, if you find them really hard to sync like i did at one time bc i did have a leak on my #3 intake boot so i couldnt get 3 and 4 to synch for crap

[Asmodeous]

Nealy, I think you jinxed me a bit....

Ok, so I'm guessing the float on my #4 carb is not set properly. Here are two pics:





Did someone say leak ?? You should be able to see the pool o gas there in the #4 carb. This is occouring because the float isn't closing right ?

Had a nice pool of gas under the bike. I had to take a break from the bike today after I got the choke working because my car REALLY needed an oil change. When I came back I was like... why does the garage smell like gas... so much more then usual....? Doh !

Any suggestions ?