Vmax running on 3 (or 2??) cylinders

[Joe Planter]

The round, white plug w/the black band is the VBoost motor. Does that 'hockey-puck' plug into that somewhere? Is the switch a 2 pole, so it has two positions? Trace the wires from the hockey puck and tell us where they run to, what the wire colors are that it goes to. I suspect it's some-sort of VBoost selectable controller.

Do any of those wires go to your schmancy high-tension spark plug wires/caps?

So there is a lead coming from the hockey puck that goes back near the battery but it is unplugged from something, it looks like it came out from under the tape and got disconnected. I’m gonna try to reconnect and see what happens

 

[Joe Planter]

 

[Joe Planter]

Okay so on the left is the wire coming from the hockey puck, on the right is a connection that somebody has cut and soldered together for some reason. Not sure if these connect, not sure where that soldered piece even goes to

 

[Joe Planter]

But the fact that something is disconnected back near the battery doesn’t sit well with me. Makes me think that might be the issue. Who knows though

 

[desert_max]

If that something has been disconnected since you got the bike, and it has been running, if intermittently, that can't be your problem. Unless it's currently dead and that loose wire forms part of your interlock circuit.

If we are down to scrutinizing custom wiring from a previous owner, you may be on your own figuring this one out. Troubleshooting factory issues can often be done successfully with remote help, but once you get off into unknown territory, you really don't know what you have. It's guesswork without hands on.

If you've convinced yourself that the carburetor set up is well, there is no rust being forced through the filter and gunking up your clean carburetors, then turn your attention to the ignition. Look for nice fat blue sparks in every hole.

Also, an assumption is that the bike ran well at some point, or that you did a baseline compression check.

 

[Joe Planter]

If that something has been disconnected since you got the bike, and it has been running, if intermittently, that can't be your problem. Unless it's currently dead and that loose wire forms part of your interlock circuit.

If we are down to scrutinizing custom wiring from a previous owner, you may be on your own figuring this one out. Troubleshooting factory issues can often be done successfully with remote help, but once you get off into unknown territory, you really don't know what you have. It's guesswork without hands on.

If you've convinced yourself that the carburetor set up is well, there is no rust being forced through the filter and gunking up your clean carburetors, then turn your attention to the ignition. Look for nice fat blue sparks in every assumption

Also, an assumption is that the bike ran well at some point, or that you did a baseline compression check.

Good point, it seemed to be running good even before I discovered that, I'm not gonna worry about it too much. Was in contact with Sean earlier and he's sending me his electrical diagnosis kit which helps a ton. Hopefully it's the ignition coils or wires.

 

[one2dmax]

That's going to be a t-boost type device and likely is the dale walker "autoboost" unit with off/normal/fulltime.

 

[Joe Planter]

That's going to be a t-boost type device and likely is the dale walker "autoboost" unit with off/normal/fulltime.

What exactly is it turning to “off/normal/full time” ?

 

[one2dmax]

The vboost system

 

[Joe Planter]

The vboost system

Oh okay, so I’m assuming this has nothing to do with the issue

 

[Joe Planter]

So I would like to note something. When I ran it the other day, I noticed that the clear red part in the plug wire on the rear 2 cylinders were very very dim, like it was barely producing a light or spark, while on the front 2 cylinders the light in the clear red part was very bright and very noticeable. Don’t know what this could indicate but wanted to note that.

 

[Joe Planter]

Inside of ignition coil connections

 

[desert_max]

Clean it up and put some real plug wires on that thing.

 

[[email protected]]

Clean it up and put some real plug wires on that thing.

Per Dman, and I agree, "buy some 7mm copper core Ignition wire by the foot (about $1-2 per foot) and re-use the stock caps or get 4 NGK SB05F caps"

Clean up that coils. Test primary and secondary resistance. If not passing, check the for sale forum here for good, used units.

 

[Joe Planter]

Per Dman, and I agree, "buy some 7mm copper core Ignition wire by the foot (about $1-2 per foot) and re-use the stock caps or get 4 NGK SB05F caps"

Clean up that coils. Test primary and secondary resistance. If not passing, check the for sale forum here for good, used units.

Good to know. Sean is actually sending me his electrical testing kit. I’m gonna swap out coils and wires and see if that fixes.

 

[Fire-medic]

Good to know. Sean is actually sending me his electrical testing kit. I’m gonna swap out coils and wires and see if that fixes.

When you get his kit, don't bother removing your coils in-front. They will take a lot of time to access. Just swap the coils outside, i.e., attach the wire harness coil leads from your bike to Sean's coils, and Sean's plug wires to your bike. You're not going to be riding it anywhere, you just want to see if the bike runs differently.

Also, take a good look at the coils in-front, as the right coil fires the left spark plug, the left coil fires the right spark plug. It's easy to reverse the high tension leads to the plugs, and it won't start.

 

[JOHN PETERSON]

 

[JOHN PETERSON]

G'day, just thought I'd send pics of indicators for interest value. Hope you like them.

 

[Joe Planter]

When you get his kit, don't bother removing your coils in-front. They will take a lot of time to access. Just swap the coils outside, i.e., attach the wire harness coil leads from your bike to Sean's coils, and Sean's plug wires to your bike. You're not going to be riding it anywhere, you just want to see if the bike runs differently.

Also, take a good look at the coils in-front, as the right coil fires the left spark plug, the left coil fires the right spark plug. It's easy to reverse the high tension leads to the plugs, and it won't start.

Good to know thank you. However how am I to remove the harness coil leads without it taking a lot of time to access? To access those wouldn’t I just be accessing the front coils anyway?

 

[Fire-medic]

Good to know thank you. However how am I to remove the harness coil leads without it taking a lot of time to access? To access those wouldn’t I just be accessing the front coils anyway?

The coil leads should be accessible without removing the ignition coils. I've just left in-place the front ignition coils when switching to COP's. Sean Morley has the Splicker Designs COP kits for sale. I like the COP's because they eliminate the plug wires, they're easy to swap-out when you have one go-bad, and 'simpler is better,' for me.

You can see for yourself, just follow the wire harness from the ignition coils to the male-female plugs, for each ignition coil.