G1 23hp Vanguard Install

[slonomo]

So I'm new to the VM series of carb, but it's not all that different to tune it vs a CV type. The biggest difference is that the VM style carb is operated by the throttle cable directly, without a vacuum assist like in the CV. The other thing I noted is that on this carb the pilot air screw and idle speed screw are on the same side, which makes tuning much easier.

I watch a great video from Mikuni Oz. If you ever need to learn about how the VM series carbs work and how to tune them, check out his videos. Just a forewarning....he's Australian so there's a thick accent, but I rather enjoy it lol. There are a bunch of videos about different things, I recommend with

https://www.mikunioz.com/how-to-videos/?v=7516fd43adaa

The carb is a 34mm and comes prejetted with a #30 pilot jet and #180 main jet and the needle is clipped at 2nd from the top.

Out of the box the carb will start and idle at 2000 rpm and rev is quick with no soot and settles down very quickly, however, it will not idle below 2000 rpm.

So as I played with the pilot screw settings I have determined that it will start and run choppy at 1100 rpm with the screw all the way in, meaning no air coming through the pilot jet. This tells me that the pilot jet is too small.

I ordered an assortment of jets, should be here later in the week. Will update then, possibly have a video or two!

[BIKERMIKEYBLACK]

At one time I talked to pjmotorsports.com
About using a mikuni on a 460 the expert I spoke with recommended the VM line a 34mm I believe
They really know how set one up and tune it this is who I will go with if I buy one

[slonomo]

Originally Posted by BIKERMIKEYBLACK

At one time I talked to pjmotorsports.com
About using a mikuni on a 460 the expert I spoke with recommended the VM line a 34mm I believe
They really know how set one up and tune it this is who I will go with if I buy one

Good add, thanks!

[slonomo]

Update:

Finally got the jetting dialed in.

As of today, July 4 2020:
Mikuni VM34
main jet 180
pilot jet 47.5
needle clip on middle notch
air screw 3/4 turns out
idle speed is 1500
just a tad hesitation off idle
no popping or fouling

Acceleration is fantastic, strong and smooth. Engine finds 5000 rpm very quickly. Speed at 5000 rpm is 33 mph with my 22" tires. Engine wants to rev past 5000 rpm, but I do not have the rev kit installed yet.

Next step: Cheetah Cam, rev kit, and high speed gears.

[slonomo]

Speed calculations:

At 5000 rpm with 22" tires my cart clocks 33.0 mph, verified by 3 different GPS apps.

According to the speed calculator below, my final drive ratio should be 9.9.

https://www.buggiesgonewild.com/speed-calculator.php

Assuming the stock G2 transaxle gearing is 13.65:1 in forward, changing these to 8:1 gears will drop the final drive ratio to 5.65, correct? Is that how this works?

13.65 - 8 = 5.65 so that would be 5.65:1 correct?

If I plug 5.65 as my final drive ratio (with 8:1 gears), my theoretical top speed would be 57.9 mph. Can anyone confirm that my math is correct on this?

[kellett5261]

thats what i got on the website i use for MPH.

[slonomo]

After fiddling with the jetting, I noticed the right side spark plug was still flooding and cutting out at idle. I called Backwater Performance and changed the intake adapter so it mounts directly to the main intake, no spacer, and put the stock #30 pilot jet back in. Big difference. That took care of it. This think will idle at 800 rpm if I want it to. I set it to 1000 rpm just so it shouldn't stall.

https://www.buggiesgonewild.com/show...=156542&page=5

[slonomo]

Here is the final setup. The carb is turned back toward the clutch side, the spacer is eliminated and the adapter mounts straight to the intake manifold with just a gasket and no sealer or gasket adhesive.

The throttle plate is mounted on the opposite side and uses a bell crank to even out the throttle pedal to match the carb. I also made a bell crank for the enrichment/choke circuit. This throttle setup works perfectly.

[slonomo]

After installing the RZR tires and wheels (25" size/ 24.5" actual) my new speed update is 34.5 mph at 5000 rpm.

[chrisr32]

Nice work, your cart looks great!