1996 Yamaha Wave Venture fuel problems

Shawn2000

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Aug 19, 2011
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2
I have a 1996 Wave Venture. It was running OK then one day after sitting for about (2) months I could not start it. Runs when I spray starter fluid in air vent, Disconnected hose from fuel filter, can blow into tank and suck gas through filter so gas is available. Pulled off fuel pump and took apart. Lots of "stuff" in there. Bought new fuel pump and installed. Still will not run on it's own. Can still spray starter fluid in and will run. Compression 114/112/114. Looks OK. What else could keep gas from getting to engine????? Also, the new fuel pump inlets are in slightly different locations. It is possible I have hoses in wrong places. From Micro-fiche it looks like I have them correct. Any help would be sincerely appreciated.
 

frozenokie

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Feb 4, 2008
Messages
309
Re: 1996 Yamaha Wave Venture fuel problems

I've had this happen to me on an older 2 stroke Mercury outboard. I found that the "stuff" I found in the pump(s) made its way into the fuel bowls where it clogged the main jets and the needle valves. You might take a look inside your carbs fuel bowls to see.
 

Fireman431

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Sep 17, 2007
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4,292
Re: 1996 Yamaha Wave Venture fuel problems

Frozen Okie has probably nailed it. It's not that gas isn't getting to the carbs, it's that gas isn't getting thru the carbs into the engine. The only true way to tell is to drop one of the bowls from the carb to see if gas is in there. Due to all of the crap they are putting in fuel, after sitting for 2 months, you have clogged jets in your carbs. Time for a rebuild. Get it done right by a professional if you can. Those carbs are very tempermental and have to be set in a specific series. I'm pretty mechanically inclined and I just paid to have my 3 rebuilt by a Yamaha tech. Amazing difference. Machine runs like it's brand new.
 

frozenokie

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Re: 1996 Yamaha Wave Venture fuel problems

Might need to take them to a Yamaha shop to fix - although, like Fireman431 said - it would be best. But if you don't have the funds and you feel comfortable doing it, then follow these steps.

Pull the carbs and take off each fuel bowl. Be careful not to set the carbs down on the bowl side without the bowls attached - you may bend the floats or float settings.

Then look for the obstacles clogging the jets or neddle valves. If it's apparent that they are clogged, use a carb cleaner from an aerosol can to spray into the holes from the venturi side (air intake side) to blast out the obstacles. Whatever you do, do not use wire or anything to "poke"into these orifices. You may damage the jets or valves.

If you can't get cleaner to come through these passages, then you'll need to remove the main jets and the floats, needle springs, and needle valves. Again, be delicate with these parts so that you don't bend the float frames or you'll knock them WAY out of adjustment. They are very difficult to get back into the right setting.

Once the needle valves are out, check the rubber sealing ends of them for excessive wear, also the sides of the needles for excessive wear. One way to check if they seem to be excessively worn is abserve the needle valves while squirting the cleaner through that passage from the venturi side. If the needle stays shut, then replace them. Probably best with that finding to buy carb kits and replace all the parts that come in the kit which would include needle valves and springs.

I have spent many hours with carburetors and replacing needles, jets, etc. I have found that on many instances, a sticking needle valve causes many different symptoms like starting and running good for a while, then "BLAP" - nothing after that. Maybe a "cough" or two trying tio get it started again. Then after a while sitting, it runs for a while again.

That's the best advice I have right now and it is what this problem sounds like to me. Just be sure to really look over that motor closely on the outside for cracked hoses, electrical wiring frayed, and similar before you start taking things apart.

Hope this helps -
 

Shawn2000

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Aug 19, 2011
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Re: 1996 Yamaha Wave Venture fuel problems

Thank you all for your response. I was hoping that there was something else between the fual pump and carbs. The rebuilt kits for these things are very expensive. The only reason I was not thinking carb was becasue typically when I've experienced carb problems on these things,one or more carbs would still perform and the ski would just stall or under perfom. I have never had them all go "bad" together and keep it from running at all. I will start into the carbs and see what I find. Many thanks for the responses. Regards.
 

slag

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Jul 17, 2009
Messages
471
Re: 1996 Yamaha Wave Venture fuel problems

There's no fuel bowl on a jetski, they dont use floats, just diaphrams. Rebuild kits are probably only $35.00 or so.

Check your pulse line to the crankcase. If its full of white milky fluid, then water is getting in your crankcase.
 

frozenokie

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Messages
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Re: 1996 Yamaha Wave Venture fuel problems

The yamaha's have fuel bowls and floats. Don't get confused with an actual JetSki which might not have them. I know this from my own bike and the shop manual that goes with it. Although I have seen on some older yamaha's that there may be only diaphrams. So get a shop manual if you need to before tearing into it.
 

slag

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471
Re: 1996 Yamaha Wave Venture fuel problems

The yamaha's have fuel bowls and floats. Don't get confused with an actual JetSki which might not have them. I know this from my own bike and the shop manual that goes with it. Although I have seen on some older yamaha's that there may be only diaphrams. So get a shop manual if you need to before tearing into it.

I'll stand by my statement that this jetski does not have a fuel bowl. No mainstream jetskis have fuel bowls on them, all use a diaphram. Don't confuse yamaha outboard motors or motorcycles with this wave venture, this is a PWC section.

http://www.boats.net/parts/search/Y...E VENTURE 700 - WVT700U/CARBURETOR/parts.html (700cc)

http://www.boats.net/parts/search/Y...VENTURE 1100 - WVT1100U/CARBURETOR/parts.html (1100cc)

Diaphram only, no floats or bowls.
 

frozenokie

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Re: 1996 Yamaha Wave Venture fuel problems

Don't confuse yamaha outboard motors or motorcycles with this wave venture, this is a PWC section.
I said "Mercury outboard" not Yamaha outboard. Besides, they make both with and without diaphrams. Jetskis on the other hand - maybe not.

slag - Don't tell me what I do and don't know by my own experience :)
 

slag

Chief Petty Officer
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Jul 17, 2009
Messages
471
Re: 1996 Yamaha Wave Venture fuel problems

You said, and I quote, "The yamaha's have fuel bowls and floats." We are in a PWC subforum discussing a yamaha jetski, not an outboard, not a motorcycle, but a jetski. The yamaha jetskis do not have float bowls. You also go into great depth on how to take off the float bowl and see if there is anything in there, when in fact, there is no float bowl. The outboard forum for mercurys is quite a bit down on the forum list.

I'm glad you have a lot of information on mercury outboards, I think thats great, it just doesn't pertain here.
 

Leedanger

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May 29, 2011
Messages
323
Re: 1996 Yamaha Wave Venture fuel problems

DI'd anyone suggest checking the fuel filters? There should be two, one at the carbs and one at the tank somewhere. Also there is a procedure to just the pop off pressure of that pump, if the pressure is too high it can actually jack the CPU all up and it won't run either. I'll add the link as soon as I'm not on my phone.

I'll also throw in my two sense that in this case there probably isn't a bowl&float, hence the reason for the pump being built onto the carb. Also I'd be very cautious with that starter spray, the RAVE valves (or whatever they are for yamaha) control oil injection by the amount of pressure in the line, so if the engine is ran with/w.out it, it's possible it will be running oil free and will fry very quickly.

This is my humble opinion, I myself am having issues with these carbs so it's not like I am any kind of pro.
 

frozenokie

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Re: 1996 Yamaha Wave Venture fuel problems

You said, and I quote, "The yamaha's have fuel bowls and floats." We are in a PWC subforum discussing a yamaha jetski, not an outboard, not a motorcycle, but a jetski. The yamaha jetskis do not have float bowls. You also go into great depth on how to take off the float bowl and see if there is anything in there, when in fact, there is no float bowl. The outboard forum for mercurys is quite a bit down on the forum list.

I'm glad you have a lot of information on mercury outboards, I think thats great, it just doesn't pertain here.

I'm only giving an example as to why his situation may be happening - no other reason, therefore it pertains to try to get someone's ear that needs help in understanding what the problem(s) may be. AND my GP760 YAMAHA has floats according to my YAMAHA shop manual. So not all YAMAHA PWC carbs are diaphram operated. Just realize it, accept it, and go on. I DO agrre with you on his particular model where I stand corrected, but do the same yourself when talking about a 97 GP760.
 

Smoofers

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Aug 1, 2011
Messages
14
Re: 1996 Yamaha Wave Venture fuel problems

Slag is correct on the jet ski carbs. Pretty much all skis - Sea Doo, Yamaha, Kawasaki, Tigershark, Polaris etc. all use either Mikuni or Keihn carbs specifically designed for pwc use. The utilize a diaphram that fills with fuel in place of a bowl. The "float level" on a diaphram carb is set via "pop off pressure" which is adjusted by different sized needle/seats and spring rates. PWC carbs and fuel systems are effectively "sealed" systems to minimize fuel spillage (since most pwcs will flip at some point).

On a wave venture 1100 I would assume it is a non powervalve motor. The carbs on this motor are Mikuni I-body series and the carb kits usually run about $50 a carb ($150 for the set). The mixture screws on these carbs are covered in tamper proof caps that would have to be drilled out to change the settings, so you don't have to worry about messing the mixture settings up. If you did rebuild them yourself, just make sure that you keep track of the needle arm and spring for each carb and re use them.

The FIRST thing I would check on your carbs is the internal fuel filters. The side of the carb opposite the diaphram is the fuel pump side of the carb. If you remove the plates off the pump side of each carb there is a tiny little filter that needs to be pulled out and cleaned or replaced. I would recommend rebuilding the carbs, personally.

Example pic (1100 carbs with the primary fuel pumping carb - cover plate removed from pump)

carb1.jpg


In this picture the fuel pump body has been removed, the red arrow points to the internal fuel filter
carb2.jpg




I am willing to bet those filters on your ski are all clogged up. I would rebuild your carbs as cheap insurance anyways. If your carbs aren't providing enough fuel to your motor you can easily run too lean and fry your top end.
 

frozenokie

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Messages
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Re: 1996 Yamaha Wave Venture fuel problems

Slag is correct on the jet ski carbs. Pretty much all skis - Sea Doo, Yamaha, Kawasaki, Tigershark, Polaris etc. all use either Mikuni or Keihn carbs specifically designed for pwc use. The utilize a diaphram that fills with fuel in place of a bowl. The "float level" on a diaphram carb is set via "pop off pressure" which is adjusted by different sized needle/seats and spring rates. PWC carbs and fuel systems are effectively "sealed" systems to minimize fuel spillage (since most pwcs will flip at some point).

Like I said, according to my Yamaha shop manual (it even shows the teardown exploded views), this 97 GP has a float. In the manual, they call it a "BODY" and work with the "float arm" in conjunction with the needle and seat with a spring. I do agree with both of you and have had my share of rebuilding diaphram carbs. On this model I have, the float is pancake shaped - not like I've ever seen - so I was even surprised myself. It's mounted sideways like a clock on the wall and appears to rotate as it "floats". My GP also has the diaphram fuel pumps mounted to the side of the carbs. So just be informed and not insulted by what I am saying and what is also wierd to me too ;)

I will also say that it seems it was a bad design and Yamaha didn't proceed with it :D
 

Imogen123

Banned
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Aug 21, 2011
Messages
3
Re: 1996 Yamaha Wave Venture fuel problems

Frozen Okie probably nailed. Not that the gas does not come from carbohydrates, is that the gas does not carbohydrates in the engine. The only real way to tell is to drop one of the bowls of the carb to see if the gas is there. Because of all the crap they're fuel after sitting for 2 months, you have clogged jets in your carbs. The time of reconstruction. Get well done by a professional, if you can. These carbohydrates are very tempermental and must be connected to a specific series. I'm pretty mechanically inclined, and I just paid for my three reconstructed by a Yamaha. Incredible difference. The machine works like it is brand new.
 

orangeman

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Jul 27, 2008
Messages
49
Re: 1996 Yamaha Wave Venture fuel problems

OK guys maybe I can help since I own a 96 venture with the 700 engine. It has the same carbs just 2 rather than 3. The carbs are in fact Mikuni Suber BN 38 MM carbs. They do not have a float but rather a pop off spring. They are not tamper proof but in fact have both low and high speed screws. I rebuilt these carbs several weeks ago using genuine mikuni rebuild kits. At about 50 bucks each they are not cheap but all the pros seem to feel this is not a place to try and save a few bucks. Herers a link for the kits http://www.iboats.com/Mikuni-Super-...8682506--**********.155889276--view_id.695912

If you are handy the carbs are not hard to work on. You can find instructions for rebuilding them on the SBT website. These carbs have an internal filter that is located wherer smoofers indicates in his post. When I did mine one of these filters had a lot of gunk in it. if I was trying to do things on the cheap I would open up the carbs and clean them out and only replace any parts that looked like they needed to be replaced

Other things to check are the fuel selector valve and the check valve for the tank vent. My check valve was bad and caused some starting problems when tank was low.

I know guys are trying to help but if you are going to offer specific advice such as offered above please take a few minutes to research it and make sure your advice is correct. If you are offering general advice such as "check the carbs" just leave it at that.
 

CWBAADER

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Jul 5, 2022
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1
Bringing this back from the dead....Have 700 twin carb that runs fine for 20-30 minutes and then drops the front carb. Can turn off and restart and runs fine for a few minutes and then drops the cylinder. Have cleaned everything, removed tank check valve, new coil pack, cleaned filters in both carbs.....any suggestions ?????
 
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