1979 GS550e is now running but idles at 2500k What now?

[Markofalltrades]

Bike finely runs after who knows how many years. (I feel close to the finish line!) After disassembling and cleaning 5 times I couldn't get gas to flow to the plugs. After I purchased a sonic cleaner and sonic cleaned the carb I replaced the gaskets. (I reused everything else.) It does have Air pod filters on it. (Cheap ones but I will get Uni once it is idling a bit better)The air mixture screws I set to 2.5 turns out. Should I turn them in some? Say 2.25 or 2? or the other way to 2.75 turns out? I am hoping the carbs are synced but know i will eventually need to purchase a manometer. Is there a order of what to tune first etc.?

 

[Nessism]

Did you replace the rubber carb boots on the head? Or, at least check them for cracks, and replace the O-rings? How about lowering the base idle screw?

 

[KiwiAlfa156]

79... The carbs in the pic you posted in another thread regarding the choke linkage showed Mikuni BS CV (diaphragm) carbs. Is this what you have? I thought (but may be wrong) that the 79 still had Mikuni VMs? These were the years where Suzuki transitioned due to emissions.

If you have BS carbs, you wont have air mixture screws, but a fuel (pilot) screws.

 

[Markofalltrades]

Yes it has the CV carbs. Is that odd for a 1979? I did have to return the first carb kit as they were not a fit for a 1979 GS. (1980 does fit) I checked the boots for cracks and they are good. When cleaning i did notice the carb turned darker gray due to the cleaning solution. This did make the brass connected to the boots less "smooth" and could cause it to occasionally stick. (I will sand them with 2000 grit later) #4 seems to sometimes stick. Is it the fuel pilot screws closest to the engine. (The ones originally capped for EPA purposes?)
The main idle knob which is impossible to reach is dialed fully to left. This lowered rpm from 4k to about 1k but then once the choke is pushed in (or out) the RPMs stay near 2500. (Underside knob below air pod filters)

 

[Markofalltrades]

Correction, it runs at 4K unchoked. 5-6k Choked. Changing the Air/Fuel pilot screws does not change anything. The new plugs all seem to be slightly black "charred" the same. (I do not run it over 30 secs each time) Could it be the pilot jet (Small internal carb jet with holes on side and tip) The jet said 47.5 on the side which was 7.5 higher than 40.0 referenced here: https://members.dslextreme.com/users/bikecliff/images/carbspec_float_height.html
It does have pods though...
Not sure where to look to determine if the engine is starved or to rich.

 

[Nessism]

You need to read, and follow through with the items listed. Shortcut, and it's on you.

http://www.thegsresources.com/_forum/showthread.php?t=171846

 

[850 Combat]

I don't know if it is true for all, but 1979 seems the last year for slide carbs. On the Suzukis I have owned and have seen, 1980 have CV carbs. '79 and older have slide. The slide valve heads are different than the CV carb heads on the 850. Smaller intake ports in the casting. I have a preference for slide carbs in general, but on my GS1000Gs and 1100G, I like the lighter throttle pull for touring over the harder pull of the slide carbs. I owned a free 1979 850G. It had points. Seller thought it had a blown engine, and delivered it for free. Ran on 2 cylinders due to a bad condenser. Switched the plug wires to the other set of points, then the other two cylinders ran. Seller thought it had a blown engine. OEM points and condensers cost more than an aftermarket ignition at that time. I had already bought the points and condensers. The wiring harness, turn signal box, headlight wiring, etc. were all pretty different on the 1979. On an 80 or newer.

 

[KiwiAlfa156]

First thing check you have throttle cable slack. If the revs change as you turn the bars left to right the cable is adjusted too tight, wrongly routed or is too short. Second unscrew the throttle stop screw until the cable quadrant isn't touching the screw and it should stall. If not, something is holding one or more of the butterflies open a tad.

 

[Markofalltrades]

KiwiAlfa156 that was the issue. THANK you.

Now the midrange...next post.
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