Freestyle Please help. Air in fuel lines.

[wanderer1]

not being argumentative but just trying to understand. how would any issues with the carb cause air in the fuel lines before the carbs? wouldnt it have to be entering somewhere upstream from the carb? i am dealing with this same issue on a ski right now. only reason i know it has air bubbles is the previous owner installed the pretty yellow see through fuel line. i assume air in the line is uncommon but because ive never owned a ski with see through lines i would not know

Novi used to sell air/fuel separators and a few companies still do because it is more common than people think. Group K did some write ups back in the day dealing with this issue and a separator was the fix. EDIT: I believe this is the link http://www.groupk.com/sep.htm

 

[OCD Solutions]

I had one in my Seadoo 951 based on recommendations by Bill O'neil and Harry Klem. Some skis are notorious for creating bubbles and super sensitive to their ingestion and that ski was one of the worst for both. There was an army of tiny bubbles marching down the fuel lines at all times. Tuning was night and day after installing the separator.

The Yamaha's however are not really known for having that issue though, not in near stock form anyway. It really wouldn't hurt to add one to any ski but I really don't think it's your issue.

Is the idle set really low causing a ton of vibration? That in itself can cause fuel aeration.

Otherwise, I'd recommend you broaden your scope a little and give a few other items a quick once over. Have you tried fresh plugs? Close up the gap? You mentioned water ingestion, have you checked compression after? Was there enough water in the hull to reach the ebox? What shape are your coil wires in? Are you running a coupler cover?

 

[surfjunkie]

So what I am getting is that this is fairly common and most have no idea air is in the lines cause oem lines aren't see through and that unless you have a tweaked to the edge high performance motor, it shouldn't be an issue. Is that a correct summarization?

In my case I haven't really noticed any performance issues but this on a new to me ski that I haven't ridden much.

 

[Sasquachcrap]

No. I would say its fairly common to have an air bubble in my fuel filter but the lines up until now don't pick up that air. Also the filters have very little fuel in them, this is what is allowing the air to be picked up.

 

[OCD Solutions]

How soft/stiff is the hose you used on the pulse lines?

 

[Sasquachcrap]

It's called fast line. It's the same clear blue line I used for the fuel line. But.....after reinstalling the carbs and sucking all the air out of the lines/filters. The ski would run and run good for a few minutes on the stand. I haven't ever observed the carbs with the air cleaner off at idle but I noticed quite a bit of vibration at low idle and the front carb was dribbling fuel pretty good at idle. It would clear up when reved. But then I started getting the runaway condition again. And noticed when it would start to run away I could hold the throttle wide open and I didn't see any fuel going into the carbs. So my question is. Is it a stuck needle or is it running out of fuel?

 

[lanmine657]

Check your primer, I had the same issue and it was air getting in thru primer, also those cheap ass fuel lines that come with primer kits usually last about one summer before they get hard and crusty

 

[Sasquachcrap]

I agree with that but all the lines are new and don't see any more air in the fuel lines. What would cause the carbs to not pull fuel in under full throttle. Tomorrow I am going to pick up two new filters. Even though these are only a couple of months old and look good. I would like to start eliminating things. And filters are cheap.

 

[Sasquachcrap]

I like pictures and I figure others do too. So here's one of the filters.

I have ran about 30 gallons of 100ll through these filters. Do you think that av gas eats up the filters.... I would think they would last longer.

 

[OCD Solutions]

Is the bottom of the oem fuel pickup solid or screened? Maybe the hoses are sucking against the bottom plate of the pickup itself?.?.?.? It would be real easy to pull the pickup, inspect and trim the tube ends on a slight angle instead of straight.

 

[Sasquachcrap]

Here is a before picture. The hoses stop about 3/4 of and inch from the bottom of the tube and I don't think the tube touches the bottom of the tank.

Here an after pic of them cut on an angle. I will have to wait until tomorrow to try the motor, the baby is asleep and so are the neighbors.

 

[Sasquachcrap]

 

[naticen]

It looks pretty at least. You can pop it with the carbs on there and see if it's sticking. I had a brand new needle that stuck before and it wouldn't run for poop to even get to the point of running away. It'd barely idle if you didn't put your hand over the carb. Dribbling is never good though

 

[Sasquachcrap]

Ok so I have a set if 38s on a good running wave raider. If I can get some jet specs I may swap them for the 44s and see if my problem goes away. Any idea on carb setup?

 

[surfjunkie]

any updates on this?

since i have threadjacked somewhat, i ran the ski i mentioned above and the ski does periodically miss/stall especially when just starting out. i assume thats from an air bubble reaching the carbs??? i noticed air bubbles in the fuel line but not so much in the primer lines. would it be best to eliminate them just to rule them out?

 

[Sasquachcrap]

The ski ran good all day Saturday until I blew a exhaust coupler. It was due for a new coupler I have no idea how old it was. So... I would try to eliminate the primer to see it it helps. I did this at first but ended up hooking mine back up. I could not single it out as the problem and it has ran fine since I put it all back together. A few more tanks of fuel should tell if its fixed.