Tapping for "pulsed" vacuum line (2 stroke)

CPI Guy · Yesterday, 02:00 PM

Hello I am trying to determine if I can add a mikuni vacuum fuel pump to a 2t Zuma motor.

I was told this should work if I tap into the intake for a vacuum port. I have to question this.
Because the vacuum line on the intake side of the carb will not work the pump... Isn't that basically the same vacuum? (Its all above the reeds)

As I understand the pump needs a Pulsed vacuum. On my Honda odyssey it has a crankcase vacuum line to get the pulse.

Can I make it work? The tank is slightly lower than the carb inlet so I need to work this out.

sc00ter · Today, 09:07 AM

My friend with the mean Vino 2-stroke did what you described but on a different scooter. He did a Zuma 2-stroke motor swap on a Honda Ruckus. The fuel tank sits in the floorboard on the Ruckus yet the carb sits above it. He used a Mikuni mechanical pump to supply fuel to the carb. He ended up drilling a hole in the crankcase to supply the vacuum, as the intake port wasn't sufficient for some reason. I forget why he didn't use the vacuum inlet from the carb, but I recall it being capped off. I also remember he used a one way check valve on the fuel line to prevent the fuel from back flowing. It took some messing around with but once ironed out that scooter moved and was dead reliable.

If I get a chance I'll try to pick his brain. I had a extra Mikuni pump that went with all the extras when I left 2-strokes behind. I think the inlet/outlet was reversed and he didn't want the hoses running all ugly, so he ordered the correct inlet/outlet orientation pump and I hung onto the old one for a spare.

Today, 09:07 AM	#2
sc00ter Join Date: May 2017 Location: Norfolk, VA Posts: 597	My friend with the mean Vino 2-stroke did what you described but on a different scooter. He did a Zuma 2-stroke motor swap on a Honda Ruckus. The fuel tank sits in the floorboard on the Ruckus yet the carb sits above it. He used a Mikuni mechanical pump to supply fuel to the carb. He ended up drilling a hole in the crankcase to supply the vacuum, as the intake port wasn't sufficient for some reason. I forget why he didn't use the vacuum inlet from the carb, but I recall it being capped off. I also remember he used a one way check valve on the fuel line to prevent the fuel from back flowing. It took some messing around with but once ironed out that scooter moved and was dead reliable. If I get a chance I'll try to pick his brain. I had a extra Mikuni pump that went with all the extras when I left 2-strokes behind. I think the inlet/outlet was reversed and he didn't want the hoses running all ugly, so he ordered the correct inlet/outlet orientation pump and I hung onto the old one for a spare.
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