Aftermarket Intake Mani and fuel petcock

[Fishman43]

How do the aftermarket intakes work with the fuel petcock for the vac. function?

I ordered the OSO carb/intake kit from VT last week, now I am wondering if there is a direct connection or modifications are required.

[Wheelman-111]

Greetings:

The CT has a barb for vacuum or oil, but not both. You can run a "Y" connector, but that may not be ideal. Better is to attach another barb, closer to the carb spigot, if you intend to run the pump with a vac petcock. 1/8" barbs with a small threaded section are exceedingly hard to find - thanks again Z50R-Blank! If you find a source, let us know?

[Fishman43]

It is never easy with these dang-ol scoots is it!

[tru72]

the real way to run a vacuum is to drill and tap a hole on the lower section of the manifold. What you trying to do is get it below the reed valve to make sure there is a constant vacuum. The other way works too but if you have the tools and time do it the other way. Ill try to get a pic of one I had done before.
aloha
D

[Fishman43]

Maybe my physics are off, but below the reed vavle don't you get presure and vacuum? That is the reason for the reed valve in the first place to keep the presure out of the intake.

[Bear45-70]

the real way to run a vacuum is to drill and tap a hole on the lower section of the manifold. What you trying to do is get it below the reed valve to make sure there is a constant vacuum. The other way works too but if you have the tools and time do it the other way. Ill try to get a pic of one I had done before.
aloha
D

Don't want to hurt you feeling but the crankcase goes from vacuum to pressure on each stroke (that's how 2 strokes work and the reeds stop the pressure from reaching the manifold). Whereas above the reeds the worst it is vacuum to atmospheric pressure to you recommendation is a poor one at best because it is hard on the petcock diaphragm. Better off in the manifold above the reeds, just like the factory guys have it.

[Fishman43]

That is what I thought Bear, thanks for verification of the intake process on that!

[tru72]

None taken bear, if thats is true what you say, and i agree with you, but if you seen a sym dd50 block the vacuum is located right under the oil pump. That is directly goes into a vacuum fuel pump. Now if above the reed cage was suppose to be better, why would they put it there? maybe because the pump works better with the pulse? The intake vacuum on a dd50 is what the oil pump is connected to. Not saying its right or wrong since it is from the factory..LOL maybe the Taiwanese got the directions and translations mixed up haha

[bakaracer]

None taken bear, if thats is true what you say, and i agree with you, but if you seen a sym dd50 block the vacuum is located right under the oil pump. That is directly goes into a vacuum fuel pump. Now if above the reed cage was suppose to be better, why would they put it there? maybe because the pump works better with the pulse? The intake vacuum on a dd50 is what the oil pump is connected to. Not saying its right or wrong since it is from the factory..LOL maybe the Taiwanese got the directions and translations mixed up haha

Hey D the sym dd50,arnada and dio all have the gas tank on the floor so a pulse style fuel pump is needed to get gas to the carb.the elites use a vacuum style petcock because the fuel tank is up high.

[Wheelman-111]

Greetings:

What he said! ^
Snowmobiles also carried their fuel below the carb. The "Pump" on some early models was a diaphragm affair below the float bowl, needing the +/- pressure pulses from the crankcase to operate. Some priming in -35 degree weather was a good idea, hence the marine squeeze bulbs found on those sleds.

[z50r-ghost]

Wheelman,

Dude, I still have had no luck finding those ever hard-to-find barbs... but, if i can manage to ever find them, I will order lots of them to share! -i have not given up yet dude....

jc

[Fishman43]

How about these barbs? 1/8", male threaded, brass... seems OK to me.

http://www.plumbingsupply.com/barb.html

Now drilling and tapping the intake on the other hand

[Wheelman-111]

Greetings:

I have a bunch of those. For the 1/8" barb you have to drill like 5/16 or larger hole! The ones Z50_R has/had use a nice little 5mm drill/tap combination and you're done. Took all of 10 seconds.

[Fishman43]

Perhaps I am confused then, Wheelguru wrote:

1/8" barbs with a small threaded section are exceedingly hard to find - thanks again Z50R-Blank! If you find a source, let us know?

Are these barbs with 1/8"mips threaded sections not what is refered to above?

[mousewheels]

For a nipple - Try your local RC hobby shop. Fuel and pressure fittings in small sizes are often stocked. Just about all stock DuBro products like below (8-32 thread). That will fit 1/8" id or so tubing.
http://www.hobbypeople.net/gallery/868759.asp

This one is smaller, 6-32 thread
http://www.hobbypeople.net/gallery/567560.asp