Gas pressure

2quick4u · Post by **2quick4u** » Fri Feb 26, 2010 7:18 pm

Guy's,

I need a little help we have a 87 v max with a 85 motor and carbs we filled the tank on Monday and went to go riding Friday and the sled was flooded bad.

The pipes and crank case where full we drained the pipes and got the sled running it ran great! We loaded the sled on the trailer to go up north and I was worried about the sled flooding again so I disconnected the fuel lines by the shut off.

We got up north and un loaded the sled hooked the gas lines back up the sled ran great all weekend. I left the gas lines hooked up and when we got home the crank case and pipes where full again the carbs are clean and it seems the gas tank vent is clear.

Do you guy's have any idea what's going on it seems like the gas tank is pressurizing and pushing gas past the floats.

Brad

eavery · Post by **eavery** » Fri Feb 26, 2010 9:20 pm

it sounds to me like maybe the floats are out of adjustment

i would start by pullin your carbs and cleaning them thourally check and make shur the needle and seat work properly and check to see if your floats float or not if so then they are probably just outa wack

Post by **Vmax540** » Fri Feb 26, 2010 10:22 pm

-worn needle and/or seat
-mis adjusted float
-float bad (hole or saturated)
- Gas tank vent blocked
-* Hole in one of the gas pump diaphrams draining gas into the bottom end thru the pulse line *

2quick4u · Post by **2quick4u** » Sat Feb 27, 2010 8:43 am

Thanks for the replys. The carbs have been cleaned and we checked the floats they are working I checked the vent on the top right of the gas tank it was clear is there another one?

Hole in one of the gas pump diaphrams draining gas into the bottom end thru the pulse line *

This could be it! I will rebuild the fuel pumps this week. What year did Yamaha start using the gas shut off switch I dont remember one on my 83 and why is there one was there a problem with pressure in the tank.

Post by **Vmax540** » Sat Feb 27, 2010 9:02 am

The 83-85 Vmax's came stock with fuel shut offs behind the radiator. Your memory is fading.......

F.Y.I.
http://cgi.ebay.com/ebaymotors/Mikuni-f ... ccessories
http://cgi.ebay.com/ebaymotors/Mikuni-f ... ccessories

eavery · Post by **eavery** » Sat Feb 27, 2010 9:24 am

really hu my primers are where the fuel shut offs should be !

2quick4u · Post by **2quick4u** » Sat Feb 27, 2010 9:28 am

I remember now.

Post by **Vmax540** » Sat Feb 27, 2010 9:35 am

http://cgi.ebay.com/ebaymotors/1983-Yam ... ccessories

2quick4u · Post by **2quick4u** » Sat Feb 27, 2010 9:38 am

I think I would rather rebuild the pumps then buy two from ebay