Register FAQ Community Calendar Today's Posts Search
Go Back   ScootDawg Forums > Performance :: Maintenance :: Technical > 50cc - 124cc
Reply
 
Thread Tools Search this Thread Display Modes
Old 09-09-2024, 03:00 PM   #1
CPI Guy   CPI Guy is offline
 
Join Date: Aug 2024
Posts: 8
Tapping for "pulsed" vacuum line (2 stroke)

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.



Login or Register to Remove Ads
  Reply With Quote
Old 09-10-2024, 10:07 AM   #2
sc00ter   sc00ter is offline
 
Join Date: May 2017
Location: Norfolk, VA
Posts: 609
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.
  Reply With Quote
Old 09-14-2024, 01:44 PM   #3
CPI Guy   CPI Guy is offline
 
Join Date: Aug 2024
Posts: 8
Thanks again Scooter! I tapped a 1/8 threaded barb into a old "rubber" intake to test it. And it instantly pulled fuel! I knew investing in NPT taps would pay off in long run!
So I gave in and tapped the aluminum intake I have on the motor. All seems well now I am rust removing and caswell coating the tank this weekend. First time trying Caswell but it is highly recommended online.
The check valve is something I need to find for our size of line.. I remember the Honda Oddyssey I had had a very expensive check valve I never ran.



Login or Register to Remove Ads
  Reply With Quote
Reply

Tags
fuel pump, gas tank, pulse, vacuum


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 09:21 AM.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.