78 gs1000

[mmiller]

I am having trouble finding out what jets i should get for my gs. I have vance and hines 4 into 1 exhaust and k and n filters. I think i have ruled out all the other options because valve clearance is within range and carbs have been thoroughly cleaned. The bike seems really lean one day and rich the next. (i dont know if it matters but I am 4000 ft above sea level)

this is my first thread so I hope I am doing right

[tkent02]

I am having trouble finding out what jets i should get for my gs. I have vance and hines 4 into 1 exhaust and k and n filters. I think i have ruled out all the other options because valve clearance is within range and carbs have been thoroughly cleaned. The bike seems really lean one day and rich the next. (i dont know if it matters but I am 4000 ft above sea level)

this is my first thread so I hope I am doing right

I have the same engine, pipe, and K&N pods, I have a 115 main, 15 pilot. It runs well at 6,000' through about 8,500' or so, it's a tad lean at 5,000.

So go a little fatter for 4,000', probably 120 main or so?

Do a complete set of plug chops to get it perfect.

You didn't post your location, but if you ever ride any lower than 4,000', these jets will be WAY too lean.
You must jet it for the lowest elevation you will ever ride at to avoid engine damage.

[Big T]

What jets does it have now?

Good source for more

https://www.jetsrus.com

[OldVet66]

tkent02, don't bring that bike down to sea level. That is basically the jetting that George put in my carbs, with the exception of 20 pilots. My engine just about burnt up in 30 degree weather. Lost 1.5 quarts of oil in that traffic jamb on the way home. With the new engine I went with a stage 3 jet kit. 130 main jets with 15 pilots. It runs fine at 1700ft. I'm guessing it will do fine in all the Eastern mountains, but would roll black smoke in Denver.

[tkent02]

tkent02, don't bring that bike down to sea level. That is basically the jetting that George put in my carbs, with the exception of 20 pilots. My engine just about burnt up in 30 degree weather. Lost 1.5 quarts of oil in that traffic jamb on the way home. With the new engine I went with a stage 3 jet kit. 130 main jets with 15 pilots. It runs fine at 1700ft. I'm guessing it will do fine in all the Eastern mountains, but would roll black smoke in Denver.

NOooo, I can't ride it down lower, it would burn up right away. It is almost too lean in town here at 5,500'. I ride it gently until I get to the higher elevations in the mountains around here.

But it rips pretty good up to 8,500' and will make it up to 12,000', maybe even 14,000' if I don't open the throttle.

I am trying to convert all the bikes to CV carbs, or Fuel Injection. They both can adjust to large elevation changes very well.

The VMs just don't cut it with the serious elevation changes around here.