Need jetting help please for GS1000 1979

[nitrogs]

Thank you Keith, excellent advice as usual. There is no accelerator pump my friend, will measure the carbs tonight Keith and report. Got a good bluish spark and my new B8ES plugs are in the post, while they arrive I shall use my old but good condition B8ES plugs set to .028. Good strong bluish spark (just got brand new Dyna Ignition and Dyna Coils fitted. One thing that I have noticed Keith when observing the protrusion of the pilot fuel screws in the carbs when looking from the engine end is that when all the screws are lightly seated the number 1 cylinder screw seems to protrude slightly more then the other screws when they are seated. All the screws are the same length and tip condition is good on all. Have checked the needle clips and all were in the same 4th groove from top thick washer above, thin washer under. Going to move upto the 3rd groove Keith. Will double check the choke lifters to make doubly sure of the seating. Got a day off tomorrow Keith so hopefully will get all done.

[srsupertrap]

Nitrog,

While you are investigating how about verify the size of the Throttle Valve Slide cutaways (1.5 , 2.0's ?) size. When you move the e-clip postion you will see that number embossed on top of the throttle valve slides ( I probably didn't have to say that ). I bring this up because when I moved to Colorado from sealevel my GS1085 with VM29's S/B with the pilot jet at 15 & K&N's etc was running very very rich on the Pilot & Needle circuit. No amount of air screw adjustment helped. The pictures of your spark plug chops looked exactly like my plugs before I figured out the 1.5 slides were too rich at an altitude of 5000 feet. I had to bump the Throttle Valve slides to 2.0 and that cured the low end rich rich condition. Now granted you are at sea level but who knows what the P.O's did.

According to the US factory manual GS1000 VM26 have 1.5 T/V slides. I looked under the GS1000S section thinking they were VM28's equipped but it also states that S model had VM26 with 1.5 T/V slides. I think is a misprint error.

[nitrogs]

I will definately check those slides srsupertrap and report back, thanks my friend.

[nitrogs]

Burning the midnight oil here in the UK, to try and get things sorted. Just to let you know I have measured the carbs and they are 28's. The number on the slides is 1.5. Hitting the sack now for a early rise tomorrow to sort the carb work, speak tomorrow gents

[hampshirehog]

Your slides are the standard ones for 28s and you should be ok with them (as you're not up near the moon like srsupertrap!)

[KEITH KRAUSE]

As you can see, lots of help here if you need it.
Hopefully you won't need to adjust the needles again since they are the most work and require a re-synch. Solid 1/3 to 1/2 throttle tests will tell.
The stock pilot circuit should be able to be adjusted. Since these are 28's I hope the cut-aways will work in transitioning to the DJ needles. Testing will tell. Hang in there. Jetting is fun (keep telling yourself that).

How many hours ahead of the US is England? About 12?

[nitrogs]

Thanks for the inspiration Keith, we are approximately 8 hours in front of you my friend. I really appreciate all the help the guys on the forum are giving me. I am afaid the GS is near on a forgotten machine in the UK. In particular where I live there are no motorcycle shops to mention and just plastic rockets roaming the streets. So it is a maintain yourself approach, hence why this GSR forum is a life saver. Most the parts for my GS I obtain from the good old US.

[KEITH KRAUSE]

Believe me, the "maintain yourself approach" is often much better than the alternatives: giving it to a mechanic who isn't trained on older bikes, or, let the bike die from neglect.

[nitrogs]

Weather absolutely miserable today plenty of rain. Stripped down the carbs and thoroughly checked all passages, jets and floats. Setup pilot fuel screws to 1 turn out. Moved the e-clip on the needles to position 3. Bench syncing done and bank of carbs fitted, air screws set to highest rpm followed by vac synch. Just need the rain to stop so I can plug chop tomorrow to see if the changes have been successful, cross fingers!!. Hampshirehog was sure right about the changing weather

[srsupertrap]

Dave,

While waiting for the rain to subside, you may want to review the VM Carb rebuild Pdf, specifically Page 3 which shows the internal components of a typical VM series carb. Does your pilot jet, fuel & air screws match the components shown in attached Pdf? I am still wondering why your spark plugs are black when you performed plug chops on the pilot circuit with stock GS1000 pilot jets (size 15) installed. This in light that you have a 1085 kit installed. Turning in the fuel screw a 1/4 and raising the needle one clip will sure lean it out but I am not convinced your spark plugs will suddenly turn light brown from pitch black unless those spitfire plugs are problematic.

But I could be wrong.

http://www.thegsresources.com/files/vm_carb_rebuild.pdf

[KEITH KRAUSE]

Dave,

While waiting for the rain to subside, you may want to review the VM Carb rebuild Pdf, specifically Page 3 which shows the internal components of a typical VM series carb. Does your pilot jet, fuel & air screws match the components shown in attached Pdf? I am still wondering why your spark plugs are black when you performed plug chops on the pilot circuit with stock GS1000 pilot jets (size 15) installed. This in light that you have a 1085 kit installed. Turning in the fuel screw a 1/4 and raising the needle one clip will sure lean it out but I am not convinced your spark plugs will suddenly turn light brown from pitch black unless those spitfire plugs are problematic.

But I could be wrong.

http://www.thegsresources.com/files/vm_carb_rebuild.pdf

All good info. How black they were concerned me too but the change I recommended is what I'd try myself. I can only assume the correct parts are in there and go by what he says is checked/done.
With a stock pilot and "ballpark" screw adjustments it makes me wonder too. The fact that these are 28's is what's different.
Nitro, what did you set the floats at? Do the 26's and 28's run the same float levels or?

[nitrogs]

Well here we go eventually the rain subsided and managed to get the plug chops. Certainly a difference. Here is the first chop at a solid 1/3 to 1/2 throttle in the order cylinder 1 to 4









What do you reckon chaps, for sure the headers are blueing

[nitrogs]

Here are the results of the plug chop at minimal throttle 20 to 30 mph for 3 miles

Plug chops Minimal throttle 20 to 30 mph. Still awaiting my B8ES spark plugs gents but good strong blue spark on all four.








What do you reckon?

[49er]

Nitro, much better looking colour on the needles, maybe a little on the lean side. That's about the colour I run. #2 though looks like it might be burning some oil.

Your pilots are still too rich though. How far out are the pilot air screws set at? If more than 2.5 turns off the seat, you may need to set the mixture screws into 3/4. How much oil are you using? It's hard to tell from the pics if some of the black might be oil, especially at lower rpms, with less heat at the plugs.
It should be pulling well in the midrange now!

[nitrogs]

Hi 49er, oil consumption is minimal my friend. The fuel screws are set just under 1 turn out. Mid range is alot better.