needles and jets GS1000 VM's

[Greenbraes]

I am in the process of rebuilding a set of VM's from a box of bits. They will be going on to my GS1000EN that has a 4-1 and K&N pods....where is a good place to start with the needle setting and main jet size. What I have at the moment is:-

main jets marked as 120
needles marked 5DL36 and have 5 groves/settings, circlip is in the middle (2 slots above and 2 below)

Any help always welcome

RB

[OldVet66]

A Dynojet stage three jet kit is the place to start. The smaller jets included in the kit worked fine for me. Z1 now sells the fuel needles, if any of those have been damaged.

[Big T]

A Dynojet stage three jet kit is the place to start. The smaller jets included in the kit worked fine for me. Z1 now sells the fuel needles, if any of those have been damaged.

A djet kit is not needed for slide carbs

The 120 will be a good starting point, may have to go a few steps higher

Set the needles on the 2nd slot from the bottom

Fuel needle - 1 turn out
Air screw - 1 3/4 to 2 turns out

[OldVet66]

It can be done with the VM's and stock Suzuki parts, but the taper in the DJ needles are a lot better, easier to dial in and are specifically designed for the application.

[Greenbraes]

thanks guys for the info, the little rebuild project is coming along, just waiting on a couple of bits and I should be able to start assembly and give them a try. Just started to paint them after their vapour blast and ultrasonic clean...will take a couple of photos too.....I know how much everyone likes photos...lol

RB

[Greenbraes]

well I know how everyone loves some photos
this is what I started with
box of bits


body after soda blast



and a couple after the bodies were painted most of the internals are in just a few more bits then onto the back plate





slowly getting there.....will have the dinning room table back soon..lol

RB

[Greenbraes]

well thats them done, just need to swap them out with the rough set on the bike and set them up.





might wait until the engine has been painted but would prefer to try them out to make sure all is well

RB

[KEITH KRAUSE]

A djet kit is not needed for slide carbs

The 120 will be a good starting point, may have to go a few steps higher

Set the needles on the 2nd slot from the bottom

Fuel needle - 1 turn out
Air screw - 1 3/4 to 2 turns out

Interesting statement. The DJ kit DOES improve performance for this model. Transition from the pilot circuit to cut-away to jet needle is much smoother due to the superior jet needle they make.
A 120 main isn't near enough. A 130 is generally perfect for typical quality pipe and pods.
Many owners have said they get decent performance by using the stock jet needles. It's all about what you want. If you compare the differences and have the ability to notice the differences then you'll want the jet kit.

[KEITH KRAUSE]

Greenbraes, Big T wasn't far off on some of the initial jetting choices but if you decide to try stock jet needles and Mikuni mains.....
130 Mains, 17.5 pilot jets will probably be needed.
Your stock jet needle e-clip position is the 3rd position from the top. Usually, 1 position richer isn't enough though it certainly gets you in the right direction. 2 positions however can be too rich. It just depends from bike to bike and the state of tune and motor condition. For initial jet needle jetting, I'd try position "4 1/2" which means you place the e-clip in the bottom position BUT you must buy some jetting spacers (approximately .022" thick) to place directly on top the e-clip. This results in position 4 1/2. It doesn't mean it's guaranteed to be right but it's where I would start first. 1 position is usually too lean but you can always test and see how the plugs look and how the performance is at solid 1/3 to 1/2 throttle position to test the jet needles. Be SURE to replace the factory plastic jet needle spacers in correct order.....thicker on top the e-clip and any jetting spacer, and thinner goes under the clip.
Side air screws are to be adjusted using the highest rpm method but 1 3/4 turn from lightly seated is a good starting point. Try 1 turn out from lightly seated to start for the pilot fuel screws underneath. Since they are the fine tuning for the pilot jets they may end up anywhere from 1/2 turn to a bit past 1 full turn because the larger 17.5 pilot's are usually enough without further richening from the fuel screws. Verify the tiny holes the sharp tipped pilot fuel screws regulate are CLEAR.
Don'r forget to remove the 2 floatbowl vent lines to improve venting and fuel flow. Leave the ports open to breath.
Replace the manifold o-rings. Apply some hi-temp bearing grease to help them last. Torque about 9 ft/lb is enough. Which means buying some Allen head bolts. Bench synch and follow with a vacuum tool synch.