Yamaha Carb/ fuel feed question

EightySeven550

Always just this close
Hey all,
I bought a 92 sq sn 701.

The ski starts if I put gas down the carb (air cleaner off)
I can keep the ski running by continuing the pouring of gas.

I have not try to run the ski for more than 10 seconds.

Should I hook it up to a hose and run it for a while and see if I start getting gas?

Should I rebuild the carb?

I have a carb from my 650, is there a difference between the 701 and the 650 carbs?

Thanks for your help all
 
the carb will bolt on but should have diff jetting
id be willing to bet that the diapham has gone bad in the 701 carb
$20 and a hours time and you back in action
 

Kaveman

Born in USA(not Kenya)
If your ski has been sitting for an extended period of time it is fairly common for the fuel to become varnish and temporarily adhere the needle into the seat. Your best bet is to remove and disassemble the carb and inspect for anything abnormal. The diaphragm, as stated by vomit is another suspect area.
 

Mouthfulloflake

ISJWTA member #2
Location
NW Arkansas
yes, hook it to the hose, ( Ill assume you know the ins and outs of running a ski on the hose)

see if it runs, and feeds itself fuel.

I run mine for more than 10 seconds off the hose.
I keep a hand on the pipe chamber to make sure it isnt melting anything, I havent burned one up yet... max run time with NO water is maybe 20 seconds, then its total cool down time.

if it wont pull its own fuel, follow the other guys advice, needle and seat is likely sticky, and there could be a crack in your pump diaphragm.

if you pull it all apart very carefully, and clean it out, you can probably reuse all the gaskets and stuff and NOT need a rebuild kit, UNLESS you tear a gasket, or the fuel pump diaphragm is busted.
 

EightySeven550

Always just this close
I should have mentioned (and meant to) the ski hasnt been run in 2 about 14 months.

I ampretty intimidated by tearing apart a carb and rebuilding it, never done anything that technical
 
Last edited:
Don't be afraid to take the carb apart. Worse case scenario is you post pictures here and we tell you how to put it back together.
Just pay attention to how it comes apart.

The needle/seat and diaphram are on the side opposite the side of the carb where the fuel lines come in.
 
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