Super Jet Carb issues?? Maybe something else! Need help

[andrewlanoue]

Okay so I'm having issues. 91 Yamaha Superjet. New fuel filter new battery new plugs new bilge new breather tube to gas tank. What the issue is im having is while I'm idling the ski runs great when I throttle up it goes about two seconds and dies on me. It starts back up idols great, I throttle up and it dies. You guy think the carb is bad? Help I need to get it going to enjoy some lake time. Thanks everyone.

 

[btmboards]

is the problem only in the water or does it do it out of the water too. has the ski been sitting for a long time. what motor is in it. how high can it rev before cutting out in/out of the water. it the gas new. what carb setup is on it

 

[JamesG]

take your carbs out and check em and clean everything. spray out your low and high end holes with carb cleaner

 

[andrewlanoue]

Problem typically only exists in the water. When it's trailed I can start it up and throttle it up pretty good. Ski sat all of last summer due to accident with the pole snapping in half. Gas was completely drained and tanked dried and fresh gas put in. It's just a stock 650. How do I tell what carb set up it has? It's only a small pull on the throttle before it dies out

 

[garretonufer]

stuck needle at closed/nearly closed position?

had an issue with one of my carbs, but it happend once up to speed, not instantly off idle.

 

[jetx]

If your running a fuel petcock make sure it is not clogged

 

[andrewlanoue]

Tried cleaning it no luck! Anyone have a used carb I could buy?

 

[btmboards]

I had the same problem right off idle and only in the water. check you needle and seat. sounds like needle isnt opening.

 

[andrewlanoue]

What needle are you refering to specifically? I have little mechanical knowledge. Also the seat don't really know what you're refering too! Thanks for your help!

 

[btmboards]

hmmmmm how to explain.... if you have the carb off, on the side that has a square cover plate turned on edge (like a diamond angle). if you take that cover off (4 screws) there will be a rubber diaphram just sitting there. remove it. At this point with the carb upright on the lest have side there will be a small metal "T ter totter" looking deal. when you push down on the middle end of it (where the center of the diapham would be) it should lift up on the NEEDLE.
If this needle dose not lift up they way it should you will not get enough fuel to run under load much above idle. Sounds more complicated then it is. you will see exactly what I am talking about when you take those 4 screws out and open it up.

 

[btmboards]

If you get stuck, take a pic, post it up and ask. pics are the easiest way to get the most accurate answer.

 

[andrewlanoue]

The needles seem to be operating good! Apart from ripping the entire carb off I'm at a loss of what else to do! Any other suggestions? Thanks again for your help!

 

[btmboards]

typicaly you would take the carb off to check andthing with it. I would say rebuild it. the rebuild kit is about $25 or $35. very simple and comes with instructions. other than that take out your high and low adjuster screws and check the ends of them for condition and wearing, check the o-ring on the end of each, spray some carb (I like throttle body) cleaner in each. there is also a really small filter in there that get clogged even with a little hair or something that wont allow enough fuel by for open throttle. Rebuild kit will come with a new one.
Also right next to the needle there is a little block you can take off that will give access to you main jets, spray cleaner through thoughs.
Other things to try would be to run a fuel line straight from your tank to your carb to bypass your fuel selector switch (those go bad/get clogged). Make sure your intake gaskets are good and that you have a good pulse in the hose that goes from your intake to you carb next to where the fuel lines hook up.

 

[btmboards]

A great way to make sure it is the carb is to borrow a good one from a friend and test it on your ski

 

[andrewlanoue]

That's actually what I'm working on right now! Thanks for the advice I'll let ya know!

 

[garretonufer]

if you're not familiar with carb work i recommend not attempting and sending it to someone knowledgeable.

 

[btmboards]

if you're not familiar with carb work i recommend not attempting and sending it to someone knowledgeable.

Ya thats not a bad idea but at the same time you cant ever learn anything by having someone else do the work for you. just pay close attention to how you take it apart, take pics for yourself if needed. when I am leaning something new I make sure I have a very clean and clear work bench and as I take it apart I lay each piece out in order I take it out by area and do one section at a time. then to reassemble you just work backwards.

 

[andrewlanoue]

I was hesitant to do it myself but I got the old one off and did exactly like you said. Had a clean clutter free work space. I got the carb off and on and exactly how it was. However, I'm still having the same issues!!! I'm at a loss.

 

[snirunner24]

I had the same thing happen in my sxr. The filter in the carb was blocked with crap, not sure how it got passed the filter in the tank.

 

[andrewlanoue]

Do you guys think my compression could be bad? What's the recommended amout per each side? Would the compression be bad if it still ran great at times??