VM Carb Slide Shim position

[tkent02]

Thanks Nessism. I thought that was probably the case. Another quick question, do PODS filter the air into the motor as well as the OEM filter.

The best ones, not quite as good. Crappy ones, not even close.

[Suzuki_Don]

The best ones, not quite as good. Crappy ones, not even close.

OK thanks Tkent

[KEITH KRAUSE]

Thanks again for valuable information. This thread will be of great assistance to others in the future that need to work on VM carbs, even though the 550 and 750 do have some differences.
I have checked out the different air holes on the rear (air intake) side of the carb. I will attach a couple of photos, although in the past the forum would let me insert one only. The bottom right hand side hole has a brass jet in it which I think is pressed in, it cannot be removed. It has no slot like the CV card to screw it out. Also it is way down inside the hole. It allows air to travel to the needle bleeder jet that the main jet screws into.
The hole above that one on the top right feeds air to the starter/choke system.
The top left oval hole is blind. I filled it with WD40 and it stood for an hour or so and was still full to the top when I returned. So I don't know what it does. I did this test on both carbs number 1 and 4.
The carb that I will be showing the picture of is No. 1, so the explanations that I am giving will be reversed for carbs #3 & #4 with air mixture screws on the right instead of the left as in Nos. 1 & 2.
The bottom left hole below the oval one does not appear to have any kind of brass jet in it. When compressed air is forced into this hole it comes out where the air mixture screw would normally be in place. All I can think is that the air jet #1.4 is one of these brass internal fittings that have been pressed into the alloy body of the carb down one of these holes. Again hoping I am making sense.

The pressed in jet on the lower right must be the primary/main air jet. This jet would regulate flow to the needle jet/bleed pipe and effect the jet needle and main circuits.
As for the passage at the lower left, if you can feel air come out of the hole that holds the side air screw, then this passage supplies air to the pilot circuit only and is regulated by the air screw.
Just so you know, I'm on vacation until this weekend and I won't be able to help if you still need it. I'm sure others will help. Have fun.

[Suzuki_Don]

Thanks again Keith. You have been a great help.

Have a good vacation.
Cheers
Don

[btbarb]

VM slide assembly

Yes, dimple down. This is important as it forces the jet needle to go to one side under spring tension. If the needle just stayed straight and under no spring tension, the needle would rattle/vibrate and soon destroy itself.

I'm in the middle of dipping, cleaning, and replacing o-rings on a set of VM carbs and I didn't notice the dimple in that slide assembly plate when I took the slide assembly apart, this old thread answered my question about which way the dimple goes - posting pics of the dimple and slide assembly back to the thread for future reference.




Bryan

[KEITH KRAUSE]

Glad it helped. The thicker spacer that goes above the e-clip, actually called a "ring" by Mikuni, sometimes has a small indentation on one side that fits the dimple. I've seen some rings have none at all while others do have the indentation.
Not easy to try mate the rings indentation with the dimple on the plate and keep them from moving while re-assembling everything. I've tried it by using a thin coat of grease to help the parts stick together but once everything is dropped down in you can't see things as you start tightening down the Phillips screws. I'm sure many carbs have had the dimple not go into the indentation and I've never noticed any issues if it did happen. And with all the parts inside possibly being swapped over the years, some rings with indentations got replaced with rings without it and it didn't seem to cause any issues, at least none that anyone was aware of. The jet needle assembly still cocks to one side whatever part you have in there but the tension it's under varies a little.