4-1, K&N in stock box VM jetting stuff

[jknappsax]

I have a 1979 GS 1000 with a Two Brothers 4-1 with a D&D can, and K&N pods. The bike came to me running rich, according to the PO, fouling the plug in cyl #3. He installed a Dyna S, and told me that that he had installed a Dynojet Stage 3 kit. The pipes have dents on the #2 and #3 cylinders from hitting. I pulled the carbs apart, and they all have 112.5 Mikuni mains (have a little box-within -a box marked on them), 15 pilots. It appears that he never installed the Dynojet kit. I believe the needles are still the Mikuni; they are a sort-of light brass color. The needles in the box with the other Dynojet stuff are a silver color.
The mains in the box are 138s and 142s (DJ).
I'm planning on keeping the pipes, and running a K&N replacement with the airbox, and either using the stock filterbox with the lid off, or just the K&N attached to the airbox. I know that the stock mains were 95s, so the mains were changed out. I talked to the support folks at Dyno, and they recommended using the 138s and installing their needles with the clip in groove#2. Does this sound like a likely starting point for the setup? The difference in Mikuni and Dynojet jets makes it hard to tell if the 138s might be too rich.

[tkent02]

I have a 1979 GS 1000 with a Two Brothers 4-1 with a D&D can, and K&N pods. The bike came to me running rich, according to the PO, fouling the plug in cyl #3. He installed a Dyna S, and told me that that he had installed a Dynojet Stage 3 kit. The pipes have dents on the #2 and #3 cylinders from hitting. I pulled the carbs apart, and they all have 112.5 Mikuni mains (have a little box-within -a box marked on them), 15 pilots. It appears that he never installed the Dynojet kit. I believe the needles are still the Mikuni; they are a sort-of light brass color. The needles in the box with the other Dynojet stuff are a silver color.
The mains in the box are 138s and 142s (DJ).
I'm planning on keeping the pipes, and running a K&N replacement with the airbox, and either using the stock filterbox with the lid off, or just the K&N attached to the airbox. I know that the stock mains were 95s, so the mains were changed out. I talked to the support folks at Dyno, and they recommended using the 138s and installing their needles with the clip in groove#2. Does this sound like a likely starting point for the setup? The difference in Mikuni and Dynojet jets makes it hard to tell if the 138s might be too rich.

If it's only rich on #3, check the petcock, it can leak fuel down the vacuum line to that carb.

My 1000 ran well with 112.5 main jet, but there is high elevations involved, I live at over 5,000 ft.
Maybe 115 would be about right? Maybe bigger.
Just a guess.
Don't know about Djet, never used them.

[jknappsax]

It's weird, because the needles in the carbs now have the 5 grooves for height adjustment, but so do the ones with all the other DJ parts. The current needles, marked 5DL36 (IIRC), seem stubbier than the ones I believe are the uninstalled DJ needles.

[robertob]

I ran a V&H pipe with the stock airbox, lid removed & KN drop-in. I used 117.5 main jets and the stock needles in the 3rd position with stock spacers. It worked fine.

[jknappsax]

Thanks, Robert. That's just the kind of information I was looking for. Anyone out there have any idea what the 117.5 Mikuni's would roughly equate to a Dynojet 138? I know trhe Mikuni's are flow-rated, whereas the DJ jets are actual diameter of the hole in the jet.

[robertob]

I don't know the conversion factor, but aftermarket Mikuni 117.5s are only about $2.00 each at most bike shops.