getting fuel to my carby ?

[k visser]

hi guys I am building a yz 450 shift kart, all is going pretty good so far thanks to this web site but i am having problems in deciding how to best get fuel to my carbie?
I don’t really want a 12v pump if I can help it.
I was thinking of tapping a line from my exhaust into the tank to pressurise it ? Has anyone done this before and did it work?
Cheers kev

 

[squat251]

thats an interesting idea, those little rc cars use that method, and it works there, but there is considerably more back pressure in that system. not sure how that would work with a full sized setup. also the heat would be a bit of a problem to an extent.

your frame wont allow you to put the tank higher to get gravity in on this? might be able to rig it up to the roll cage, there are some rednecks on youtube that used an old fire extinguisher mounted to the rollcage for their shifter.

other than that, there isnt many options. you could try to put a nipple on the exhaust and see if it works, i would let it idle a while to see if the line melts, wont do you much good if it melts out on a trail.

 

[k visser]

Thanks for the input squat. I will add a photo soon but its a road kart with a tank between your legs no roll cage.

 

[r_chez_08]

can you not install a pulse powered fuel pump like those seen on gx200 race karts-
http://www.mikuni.com/c-fuel_pumps.html

 

[k visser]

Do they work of vacuum or a diafram like the kt 100s which I pulled out of my kart . How would I hook it up to my yz450 motor? Easy or hard ?

 

[anderkart]

The most dificult part would be installing a 1/4" barbed fitting in your crankcase, valve cover or intake. You'll probably want to use one of the large round Mikuni pulse pumps for your engine.

I found links to some pics of a WR450/YZ450 powered shifterkart in post #17 at this link:
http://www.thumpertalk.com/topic/251846-450f-powered-go-kart/
It looks like he installed his pulse fitting in his valve cover.

Sometimes the carbs needle and seat valve cant handle the additional pressure of a fuel pump and develop flooding issues. Mikuni sells replacement needle and seat valves made for fuel pump use for some carb models but not all. This video shows a return system that you may have to instal if your carb floods with a fuel pump:
http://www.youtube.com/watch?v=t2bRbaph_Ys

 

[anderkart]

Hey I did some more research and learned the Yamaha YZ450F bikes were fuel injected. Does your have a carburetor or injection?

If its fuel injected, A pulse fuel pump may not develop enough pressure and you'll probably need to use an electric fuel pump like the YZ450f bikes originally came with.

 

[k visser]

It's a 04 model carby no injection.

 

[anderkart]

Good, I found some more pulse fuel pump info/pics you could research here in this thread: http://www.ekartingnews.com/viewtopic.php?p=622852&sid=2bc89c337680b105853563c919cac345
If you registered at these other 2 forums I linked, you could probably go to those guys home pages to get their contact info and send them an email or PM.

 

[k visser]

i have been searching and couldn't find anything out about if i could hook a 12v pump on to my yz 450f (04 model) motor without upgrading the sator ? and use no battery ? if you know what i mean.

 

[anderkart]

I think you could just instal a Battery Eliminator, but I'd suggest you post a thread asking the guys on the thumpertalk forum to be sure: http://www.thumpertalk.com/forum/13-yz-400426450/

 

[k visser]

Hi guys thanks for the help , I think I'm going to try and pressures the tank. Photos and a outcome to come. Whish me luck

 

[anderkart]

Are you going to pressurize the fuel tank with your exhaust?