Yahama @ MUCH FUEL!

[crash12888]

10-4 on the humidity!!

[rschap1]

x2 on the ethanol and it's sucking moisture from the air in:(

Thanks for your sharing the info on your two Yamahas. I did pull the neighbors carb and float bowl. One of my first thoughts was stuck or failing float. So I have emptied the bowl and cleaned. That all looked good and we still have yet to see temps cold enough for freezing (in MI so it won't be long though-YUCK). I am pretty convinced that it is a failing fuel pump. It starts SPEWING fuel out the "breather" hose (from engine to aircleaner box) right after decreasing rpms. If holding the throttle wide open it doesn't seem to spit fuel out this tube. Let off and a steady stream. My idea is as soon as vacuum from the cranckcase starts pulling on the pump. I have yet to locate JUST a diaphragm...only complete ($50-$80) pumps. Appreciate it if anyone might know a source for rebuild kit or cheaper solution...THANKS I will be calling neighbor today to find out atleast what G__ model Yamaha he has to narrow down part search some. THANKS AGAIN!!!

[smallblock450sl]

That's what I was going to ask, what model Yamaha are you working on? All G1's and G2's and some early G9's and G8's have rebuildable fuel pump kits. The fuel pump would need to be metal and round with 6 screws holding it togeather to be able to rebuild. If it metal (square) or plastic...there throw away pumps. Let us know what you have. Dave

[DOOmsman]

Back to chap the fuel pump is a mikuni look that up and you can fide the parts you need try the sponsors and then shade tree motor sports.

[DOOmsman]

Go to the fuel pump sticky

[crash12888]

I have a John Deere mower with the Kawasaki engine that uses a pulse fuel pump. Don't know the price on them verses cart pumps but might be something to check out,
Walbro also makes pulse fuel pumps for two and four cycle small engine applications. just some alternative ideas to check out.

[rschap1]

Doomsman:Yeh, that sticky thread was really nice.
Great that stuff like that gets shared!

crash12888: My JD 318 has a pump that's pretty similar too on its Onan engine.
A couple co-workers have recommended two local places that are Yamaha dealers (Babbits and Metric Motorsports in Muskegon MI) to check. I have passed all your info on to him and those two sources. He says that he isn't opposed to just grabbing a whole pump and maybe I will assist with install and the oil change. He doesn't sound nearly as cost concerned as myself (I admit it, I am tight as bark on a tree!!!!!) I would probably search a liitle harder for a cross reference diaphragm or a cheaper pump with comparable specs, but I will admit, he will probably save himself some time for a few dollars (and make things easier on me if I end up helping). Really appreciate all the info here!!! THANKS

[rschap1]

SSSSssssOOOOoooo I am going to help change the oil in this thing tomorrow. Neighbor says he's got the pump and that looks like it should be pretty straightforward. I have not looked into the oil change yet. What can anyone add for this? Neighbor says he has no manual and no idea what kind of oil or where the drain is etc...THANKS!!!!!!!!!!!!!!

[DOOmsman]

Well with out going into detail the drain must be on the bottom and I use synthetic oil for a few dollars more I am sure its slickery. You will know what I mean if you spill any..