78 GS1000E possible 2nd carb problem?

[dluszcz]

While doing research on here to find out what I'm doing wrong tuning my carbs, I found a thread that stated that the air screws should be bottomed out gently, then turned out 3 full turns to start.

Well, I found a thread in my previous search that stated 1 1/4 turns out. So, for all my tuning attempts, I have been bottoming out and turning out 1 1/4 turns.

I'm still in the same spot though. I have 2 cylinders lean, 2 cylinders rich. So, I'm guessing that if I turn the screws out 3 full turns, I should have 4 cylinders rich and then I can work backwards.

Looks like I'll be buying another set of new plugs so that I can make sure that I can read them better.

After the bike ride today, here are a couple of pics of my header pipes. The plugs show the same type of markings. 2 plugs white, two plugs black and sooty.

At least I only went 30 miles or so and didn't overheat the engine. Strong Chicago winds and 55 degrees probably saved me!

http://i223.photobucket.com/albums/dd22/dluszcz/1978%20GS1000E/IMG_20110501_183916.jpg

http://i223.photobucket.com/albums/dd22/dluszcz/1978%20GS1000E/IMG_20110501_183928.jpg

So, did I do any engine damage? I took it around the block twice after turning out 3 full turns, and I noticed a slightly better throttle response.

Just looking for help on what I'm doing wrong and if I'm even starting off in the right direction.

[Nessism]

Your bike has VM carbs, the 3 turn recommendation is for CV type carbs. VM carbs have two adjustable screws: pilot fuel screw on the bottom and pilot air screw on the side. Fuel screw should be roughly 7/8 turn open and air screw, 1-3/4 turns open.

You don't state what you have done to the bike in terms of maintenance. Are the carbs clean, points clean/gaped, are the carbs jetted for that header, valves adjusted, etc? There is much to do on a 33 year old bike.

I doubt you damaged the bike. Oh, and you can't judge the mixture by looking at the plugs unless you do plug chops (search out info on this if you don't know what this means).

Good luck

[dluszcz]

Complete tear down, dip, and rebuild of carbs. I reused all the needles, floats, and rejetted to 102.5 from stock 95 because I went to pod air filters.

Also moved the needle down to position 4 instead of position 3 to move the needle up a little bit.

New universal petcock purchased last year around May. (Previous post regarding possible problem with new petcock leading me to this point)

Adjusted float height as advised in same previous post.

Yes, I have the VM carbs. I didn't see that the research thread I was looking at was for the CV carbs. Oops.

I don't remember what I did on the bottom screw (pilot screw).

So, I went out to the garage. Turned the air screws 1 3/4 turns out and turned the pilot screws 1 full turn out.

Fired the bike up and the idle was a little more smoother than when I took it out this afternoon. However, I won't know how much of a difference it makes until I take it out tomorrow after work.

[Nessism]

Do your pilot fuel screws all have a full pointy tip? The tips like to break off inside the carb body.

As an aside, are you sure the main is enough? I'm not a jetting guy but a 102.5 seems small for a 1000 with pods and header.

[dluszcz]

I bought both 100 and 102.5 jets from Z1 and was advised that I should use the 100 if I stick with the stock air box.

I should go up to the 102.5 and move the needle position from 3 to 4 when switching to the pod filters.

I really don't know if 102.5 is enough, but following the advice I have received and the condition of the plugs suggests a 50/50 chance that I followed the wrong advice.

But, 2 plugs are rich, 2 plugs are lean. I'm thinking that would mean that the jets are big enough, but the position of the pilot and air screws needs to be tweaked.

Maybe I should just ride sporadically until the guy has a free weekend to help me sync the carbs properly. Could be the solution to all my problems instead of trial and error.

But I so WANT to ride what I spent the last 1 3/4 on rebuilding from the frame up!

[Big T]

are 1-3 lean and 2-4 rich?

As for jetting, you should be up in the 115 range for headers and pods

Did you have this problem when you had the airbox on it?

You dipped your carbs, did you replace the intake boots or their O rings?

Did you cap the vacuum port on the #3 carb?

[dluszcz]

Counting the carbs starting from throttle side, 1 & 3 are rich, 2 & 4 are lean.

Wow, 115 for the jets?! I live in flat lands (Chicago area) and was told that for my altitude, I should be around 102.5. I should only go up 3 from stock, which is 95.

Yes, I had the excessive gas coming out of carb #3's overflow tube with the stock air box. I really wanted to switch to the pod filters because I like the look and the ease in which I can remove the carbs now.

I did not replace the intake boots, but I did buy the o-rings and replaced those. (Secondary note, 1 of the header bolts has sheared off and I now have to figure out how to get that out. It's seized in there pretty darn good. Precision tool guy that helped me with the carb body on my old set hopefully can work some magic on this bolt so that I can no longer have a leak) Could that be another issue? Yeah, I know it is an issue. I just don't know how to fix this one!

I'm unsure why I would cap the vacuum port on #3. Isn't that the vacuum line that goes to the petcock?