GS550ES with firing issues PLEASE HELP

[Anonymous]

I did add a k&N opened the air box and a full 4in1 exhaust system. I jetted it two steps richer but did nothing to the pilot mix screws. Should I richen them up too.
Also for a carb sync do I just adjust the two vacum levels to be equal since this bike is a 2 x 2 barrel
Thanks

[Anonymous]

To do a carb sync for a 2barrel 550es can I just use two vacum gauges??? what rpm do I set it to
Thanks

[KEITH KRAUSE]

I did add a k&N opened the air box and a full 4in1 exhaust system. I jetted it two steps richer but did nothing to the pilot mix screws. Should I richen them up too.
Also for a carb sync do I just adjust the two vacum levels to be equal since this bike is a 2 x 2 barrel
Thanks

You should list any mod's at the start. Removing the airbox lid and installing a 4-1 pipe will cause a lean mixture to all 3 jetting circuits.
You say you jetted "two steps richer", which I'm assuming is for the main jet? With Mikuni jets, a step equals a 2.5 increase. A full size increase equals 5. This generally isn't enough for removing the stock airbox lid and a good pipe. 2 full sizes is closer in my opinion.
Then, you must raise the jet needle. If a U.S. model, your stock jet needle isn't adjustable. You can try shimming but I can't help with shimming because I always use jet kits. Your needle needs to go up about 1 position. You spend the most time riding on the needle circuit, so get it right.
As for the pilot circuit, 1/2 to 1 full additional turn out on the mixture screws will help.
When synching carbs, either two or four, the vacuum levels need to be as equal as you can get them. Within a 1/2" of each other is good. Every synch I ever did was with one vacuum tool. I synch at about 3,000 rpm.

[Anonymous]

Sorry I didn't add that. The dude at the dealer told me that putting in a K&N and openin the air box wouldn't need a jetting increase.
Yes I went up 5 on the main jets from 97.5 to 102.5.
When you say the needle has to go up one, can you define what one size is?
I thank you very much for your help you've told me exactly what I need to know.

[skreemer]

the needle isn't a size change it's a position change. If you open the top of the carbs and pull your diaphram/slide assembly you'll see the needles hanging underneath.

To get the needles out of the slide assembly you need to gently tug the needle out till the end of its travel and then use a pair of pliers to gently tug the plug out of the top (forgive me I don't know what it's called but if you look into the top you'll see a white cylinder piece of plastic with a cross on it about 3/4 of the way down). It takes a bit of force to get them out but be steady so you don't damage them. then just tip it over and pull out the needle. Be mindfull of the clip, retaining washer, and spring. Note carefully the order and placement. If your needle has ridges near the top you have an adjustable needle. and you just need to change the position of the E-clip. If you do not have an adjustable needle I'm not sure of the reliability of putting that many shims into place... but I think you can buy the needles from Dyno Jet directly... ask around more here or at your local shop.

[KEITH KRAUSE]

To add to what skreemer said. You can ask here or make a new topic about shimming the jet needle. I always go with jet kits, but you may get some help and just try shimming if you're concerened with cost.
I just want to stress that it's important to get the needle circuit right. It's the most important/most used circuit in my opinion. Taking off the air box lid will significantly increase air flow. Enough to make the bike run too lean with a stock positioned jet needle. So be sure to raise it. If you use a shim, I think the equivalent of 1 position (if you had an adjustable needle) will be enough. A typical jetting spacer is about .022" thick and is used to raise the needle "1/2" a position. So you would want to raise the needle a full position, or about .044". I can't say for sure, you have to test, but I believe one full position will be enough. If it was rich at one full position raised, then you would have to try a 1/2 position change as I described. One of those two suggestions I hope will set you up right.
As for your main jet, I really doubt that one full size up is enough for a removed lid and pipe. For just the pipe, maybe, but not with the removed lid. Go up another full size and test. You may have to go larger than that. Do a full throttle test/plug read to see what's going on for the main. 1/3 throttle test for the needle circuit.
Don't assume the bike is running good, get plug reads. A lean mixture can fool you. The bike may feel strong, but if the plugs are running white, you'll over-heat the motor and bad things happen.

[Anonymous]

I was wondering you said turn the pilot mix screw out 1/2 to 1 turn. is this the screw under the carb near the main jets in the bowl, or the one on top near the manifold areas
Thanks

[KEITH KRAUSE]

I was wondering you said turn the pilot mix screw out 1/2 to 1 turn. is this the screw under the carb near the main jets in the bowl, or the one on top near the manifold areas
Thanks

I'm not positive about your carbs, but I think your mixture screws are at the top, near the manifold area as you said. Make a topic asking other owners with your model to be sure. There are other external screws on carbs that you don't want to turn.
And my suggestion was to turn the screws out an ADDITIONAL 1/2 turn or so, just to be clear.
You should get a manual.

[Anonymous]

Thanks for your insight
I'm thinkin that turnin the pilot jet in the bowl will not do anything cause I can't see that it would. so I would agree with you but my manual doesn't say anything usefull about idle mix