'81 Gs1000L carb probs.

[Anonymous]

I just bought this bike. The problems is when i fill it with gas, gas slowly drips out of the carbs when the bike is off. I think the petcock is broken also. If i put my hand under the airbox, its all wet with gas. And my bike will not idle. It sounds rich to me. I have to constantly rev it to keep it running. I think the carbs need a rebuild, does anyone make rebuild kits for these carbs? Also the bike came with a vance and hienz pipe on it. I talked to a couple people who told me that you have to change the jets if you put a pipe on. Is that true, and what size would stock jets be?
thanks
tom

[KEITH KRAUSE]

Fix the gas leak before worrying about the jetting.
Take the petcock apart and clean it up. If any parts look worn, replace or get a rebuild kit if one's available. Replace the fuel and vacuum lines. Be sure the gas tank is not rusting. Repair if it is. Take the carb bowls off and check the float needle valves and their seats. If any dirt or rust, remove the valve seats and put a bowl under the carbs. Keep each valve with its seat. Turn the petcock to prime and let some fuel flush through the carbs.
If any of the float valves has too deep a groove worn around the tip or the spring is weak/broken, replace the valve. If the valve seat has a worn/hardened o-ring, replace it.
If you do all this, the gas leak should stop. If it still leaks, then you need to take off the carbs and check the float heights.
If the motor is completely stock, (air box lid is on too) then try 1 full size up (5) on your main jets. Your needle circuit should be Ok. Adjust your mixture screws out 1/2 to 1 additional turn from where they were stock. Take plug reads and go from there.
I'm not sure about your model, but the '80 GS1000E/ST has 107.5 main jets.

[Anonymous]

'81 GS1000L Carbs

I agree with everything Keith mentioned, I just completely rebuilt my '81 GS1000GL. I would only add a couple of things: The machine may have been sitting for an extended length of time, so you should assume that the carbs may have deposits and tarnish build-up. A rebuild would be the single best thing you could do. Kits are available for between $19.00- $25.00 ea.
The main jets on my '81 are 115s, slightly larger than was used in '80. And the paperwork that came with my V&H four-into-one recommends increasing the main jet to 125. However, that's not all...it recommends the installation of a Dynojet Stage 1&3 kit to ensure accurate throttle response across the rpm range, and also to accomodate pod filters, since they too will create an overly lean condition. Good Luck!

[KEITH KRAUSE]

The stage 1 kit is only for bikes with a replacement air filter element such as K&N and still using the stock exhaust.
The stage 3 is for pods and pipe.
I'm a little surprised they tell you to go up two full sizes on your mains for just the pipe. Do you still have the stock airbox? How did it run at full throttle with the 125's?
I mentioned the bowl flush/check method because it may be all that's needed and is within most peoples ability. If it works, it saves you from a lot more work.

[Anonymous]

My GS1000GL has only 125 miles on a brand new rebuild, with a Wiseco 1085 big bore kit, and I've restrained from full throttle so far, but otherwise the plugs seem to look normal during the usual running around that I've been doing. I think I should also point out that the jetting recommendations for the V&H pipe is specifically if NOT using a Dynojet kit. On a GS1000 Pre-'80, the directions indicate to go with a main jet of 117.5 or 120, and adjust the fuel screws one or two turns from fully seated, and on an '80 or '81, increase the Main Jet to a 125, but raise the pilot jet to 42.5. On both, it recommends removing the stock airbox lid.
I'm still using the stock airbox, but thinking of going to pods, and doing the full tuning after I've completely broken in the new engine.

[Anonymous]

Thanks for all the replies. The bike hesitates at around 3000rpms. then it will go up the rpms pretty good. It has a k&n filter, but the stock airbox. I'm going to try all the suggestions you guys gave me and see what i have.
thanks
tom

[KEITH KRAUSE]

thcash. Those recommendations sound OK.
What's interesting is no mention of the needle circuit re-jetting. You spend the most time riding while on the needle circuit. If you take off the air box lid as recommended, it WILL lean out the needle circuit quite a bit. These bikes come a bit lean from the factory as it is. When you factor in the pipe and taking the air box lid off, you're quite a bit leaner. Mixture screw adjustments won't help enough either, maybe in town just puttin' around.
The needles have to be raised at least a 1/2 position by using a jetting spacer or maybe a full position. This is if you get the jet kit adjustable needles. If not, you have to shim up the stock needles. You also should increase the size of the vacuum orifice to the diaphragms for better throttle response.
I recommend the pods or keeping the stock box with the lid on. Running with the lid off doesn't give you the power of pods, but you still have to completely re-jet. If you do go with pods, remove the two floatbowl vent lines so the jets can draw fuel better too.