VC 460 tuning?

Gritsngravy

I have a VC 460 motor that I haven't been able to get tuned from the get go, so I'm looking for any ideas or tips. So here's my story.
The cart is a G2. Initially it was hooked up to the stock pulse type fuel pump. It was over fueling and pouring gas out of the overflow. So I made a fuel return and that problem was fixed.
So now it won't start without choke and backfires if you don't catch it right away. After a big backfire it starts up and I can turn the choke off and it runs fine. VC tech told me to check valve lash an it may be rich. Lash was adjusted and it helped a little.
I've worked from lean to rich and it just will not start without choke, which isn't convenient on this motor. It starts easier on the rich side, but then the motor doesn't shut off, even with the idle screw all the way back. When it's leaned out enough to shut off this is when it really backfires starting up.
There is no backfire on deceleration.
I've also tried doing a gravity fed tank to see if it was my fuel set up, but this didn't change anything.
Any idea?

BGW

__________________
This advertising will not be shown in this way to registered members.
Register your free account today and become a member on Buggies Gone Wild Golf Cart Forum

Shepard

I would check my gaskets for leaks. Are you using the fuel pump pulse line hooked to the carburetor insulator? Make sure there's no leaks. I have a VC 460 and I installed an adjustable main jet in the carb. It runs like a car or truck with a hand choke for me with my adjustments. I use a key start like a truck and it idles at about 1200 rpm. It shifts with no problems. I'm not comfortable with my engine turning off when I take my foot off the gas pedal.

Cold start -- pull choke - start - push choke in about 1/2 way - idle till warm - push choke in all the way. Drive it. I drive it like a truck - not just a few feet like some.

Here are a few pictures of my setup. Its simple and clean. I listened to all the pulse pump issues people had. I went with a 3-5 lb low pressure electric fuel pump. Lots of fuel filters. I listened to all the people and Arron from Vegas Carts and did a very simple fuel return using a 1/4 x 3/8" tee into the old tank vent. The tank cap is vented on mine. The carb has an adjustable main jet and the choke uses a Honda OEM mechanical choke plate for a pull cable. You can see from the plug it burns pretty clean. Its still a little rich - but just a little

Attached Images

	G2 Mini Truck 197.jpg (233.2 KB, 0 views)
	G2 Mini Truck 184.jpg (230.4 KB, 0 views)
	G2 Mini Truck 118.jpg (237.4 KB, 0 views)
	G2 Mini Truck 186.jpg (221.4 KB, 0 views)

raydhd

To cold start my 460 which has the idle mixture screw out at 3 turns I pump the throttle from idle to 1/2 open while cranking.It works every time.Since there is no accelerator pump I assume this disturbs the air flow enough to cause a rich starting condition.Just holding the throttle in some given position does not work for me at all. P.S. I also as Shepard am set up as a key switch and not pedal start.

Gritsngravy

Thanks, that's some good info. I think I'll go with the key start too and copy that electric fuel pump set up. I'm using the pulse setup now with a return into the tank.
Just FYI, it still needs choke and backfires even when warm. It runs fine once going. This is what has me confused.

sho305

What works best for my clones is set the idle mix for best idle then turn it open half turn so its richer a little. If you feather 0-25% throttle starting it fires right up. Set the idle to a low speed just faster than the starter turns it over or just above the compression release.

If you have not you need to put the relay on to kill the engine if using pedal start. I posted in clones how to do it they are cheap, get the harness its all less than $10 and it will kill when you let off the pedal like the original engine in a G2 or G9. For emergencies if you need to pull start it you just pull the relay out of the harness and it will run all the time, or unhook the coil kill wire.

alparmer

I'm still getting used to starting my VC engine. I ended up getting rid of all of the bypass switches, etc.

I use two switches. One that uses 12v from the key to the solenoid. The other switch is connected to the ground engine kill from the motor. So, it starts like a push button car and then to turn it off I press the other switch. There are lots of ways to do,it, but I like that if I leave the grounded kill switch off, it also acts like an anti theft hidden switch.

My engine will not start unless you give it some gas. Then I hold it for a few seconds and it will idle fine. My mixture screw is set to 4 turns out and it seems to like it there. I think it came with 3 turns out from the factory and it caused backfiring during deceleration. After enriching it, no more backfiring. I'm coming up on ~10 hours of use and it feels like the idle is getting smoother as time goes. At first a good idle was around 1.5k rpm, and now 1.2 is pretty good. I know it sound high for an idle, but I think it's due to the higher compression on these engines.

I also had the gas overflow problem and I put a t by the carb to fix that. To be honest, it seemed like the engine will start easier before the T.....until gas started pouring out of the carb.

BrewCityMusic

Personally, I'd hook up a choke and make life easy on Yourself. "Shouldn't Need to choke" (as the kits say) is a pretty easy to believe statement if You're in Las Vegas, Texas, maybe even South Carolina - but build one here in a State like WI and it starts getting into the 40's regularly these become fiddly little "B**ches*, as does almost any single-cyl engine during colder times. These may be "Rocketship" versions of a "Lawnmower" engine, but if You treat them as the latter it's a lot easier to deal with the downsides.