Engine Start with VP-200 and dual mags

Auburntsts · #1 10-23-2012, 06:45 AM

Anyone running a VP-200 and dual mags? My left mag is a Slick retard breaker (6393) and I want to verify the mag switch setting on the VP-200 switch panel. Because there's no start position (just Off, Left , Right, and Both), I'm assuming that in order to avoid kickback that I should select Left for starting and then switch to both once the engine is running. Does that sound right?

rleffler · #2 10-23-2012, 10:13 AM

Todd,

I have a similiar configuration, except for a VP-X Pro. The VP units really don't come into play. I also have a G3i electronic ignition and I use an ACS-510 ignition starter switch.

In the G3i manual, it states: "ACS-510 ignition switch, in start mode, the right magneto ground jumper needs to be removed to use the right ignition also during start up."

It appears that both mags are used, but I need to validate that. As I started reading the manuals, I just came up with more questions than answers. What I couldn't quickly find is when the switch is turned to start, are both magnetos engaged.

The ACS-510 schematic states to remove the ground jumper if you have a retard magneto.

The question I have, is that I believe you will need a SlickStart or somthing similar to replace that function since you have a retard magneto. The G3i boosts the spark in my case, so I don't need a SlickStart.

Since the FWF is the part of the build that I still have significant areas in which my knowledge base needs to improve, why would one mag prevent kickback as oppose to both being engaged?

bob

Auburntsts · #3 10-23-2012, 12:53 PM

Bob,
I'm not real sure but I think it has something to with normal mag timing being too advanced for starting. I believe on a traditional rotary ignition switch that the START position grounds the non-starting mag (unless both are impulse coupled) disabling it until the switch is released and springs back to BOTH. Based upon that logic and the fact that the VP-200 mag switch on the switch panel does not have a START position, I'm thinking I need to start on LEFT. I'll need to check, but you're right in that I'll need a SLICK start if the 6393 doesn't have an electronic buzzer doohicky built-in. However, that doesn't impact which mag should be on for start.

Here's a link to a Mike Busch article on the subject:
http://www.avweb.com/news/maint/182843-1.html

dmaib · #4 10-23-2012, 07:25 PM

I believe you are correct, Todd. But, I am not knowledgeable enough to say for sure. Hopefully one of the engine guru's on the forum will confirm this for you.

Walt · #5 10-23-2012, 09:18 PM

The 6393 mag has retard points and requires a slick start module. If you don't use a key switch there are some other options you can use to wire it. Have a look here for some diagrams.

fatherson · #6 10-24-2012, 12:06 AM

Sorry I didn't see this earlier today. I'm away from the office tonight, Todd, but I'll check on this first thing in the morning. For now, I will say to be a little careful about comparing the VP-200 and the VP-X; they are quite similar in many ways, but somewhat different in a few, especially in the starter circuitry.
--
Stephen