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Please help me!!

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slobra300

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First off thanks for reading. I have a fuel feed issue on my 1997 seadoo gsx with the white 787 motor. First day we rode it would only do about 45mph and had a couple of bad hiccups. Next day would start fine and idle, but when you gun it, it would fall on its face. Out of water it will redline, in water wont even plane.

Parts I have replaced...
1. Fuel selector valve (was coroded and nasty)
2. All gaskets and diaphrams in the pump housing on the side of the carb to include the little tiny filter
3. Removed stock fuel filter, installed p/n FS20011 inline fuel filter and replaced all stock fuel tubing, vent tubing. Only line that I didnt replace was the return lines but they look pretty good.
4. Removed sending unit and cut out little screen at the base of it. Everything looks good.


Still wont suck fuel like it should. The little clear inline fuel filter on my 98 GSX Limited stays almost full when running and when at high rpm's. On the 97 with the fuel feed issue, as soon as start it, the fuel sucks out of the clear fuel filter faster than it is coming in.


One thing I noticed is one day when I was removing the sending unit there was excessive pressure in the tank when I removed the first line off of the sending unit. Now there is a check valve that lets clean air in right in front of the seat, and there is a 1.5psi pressure release valve that lets excessive pressure out mounted on the hull. Im wondering if this pressure release valve is not working causing the gas tank to build to much pressure. If that was the case, would that cause an issue with the gas being sucked out of the tank?? Seems to me that it would only help but Im desperate. Ive been messing with this thing for a month and cant fix it. PLEASE give me your ideas!!! Thanks in advance for reading this long post.. -Chris
 
I don't think excessive pressure will cause the problem your having but it is simple to check, just unscrew the gas cap a little and test, be careful not to get water in the tank.
It sounds like a carb problem, have you cleaned them thoroughly including the main and pilot jets, internal filters, of both carbs? Also verify that your acc pump is working properly. You don't need to remove any of the screens or internal filters or add any for that matter, that will just cause other problems. The system works great when everything is clean. Changing fuel lines is always recommended. Make sure all fuel connections are snug.
I suspect it is running lean which can cause serious engine damage, you should check your compression and make sure it is still good.
 
double check your fuel line connections. Think you got some mixed up? Did you replace the little spring, in each of the carbs?..if so, replace them with the oem ones that yuo removed.
 
Check the pressure line coming from the engine and make sure it is not leaking or connected incorrectly.
 
ski-d00... I have not removed the carbs and completley cleaned them. I have only removed the acc. pump and replaced the gaskets and diaphram and micro filter. I didnt think that it was a carb issue because I can clearly tell its a fuel feed issue. The inline fuel filter barley has any fuel running through it when running. Also once in a while when in the water, if you let it idle for about a min. to let the fuel build up in the inline fuel filter and gun it, it will pull hard and run great for about 15 sec. Once it has depleted the stored fuel in the filter, it falls on its face. I will try running it with the cap removed to verify the pressure idea...

SRUSH - I have replaced the fuel selector valve with an oem part from seadoo along with all new fuel line from an autoparts store. (not the oem gray crap) I have also triple checked to verify I have the correct connections on all my fuel lines.

timmyboy76 - I have not replaced any springs. Which springs and what do they do?

jhjesse - I have verified the pressure/vacum port from the crankcase that drives the acc pump. It is working great. A side note: I actully broke the nipple off of the acc pump side plate and replaced it with an oem piece.



Maybe it is time to tear the carbs completley down. I just know that when it gets fuel it runs great so I wasnt thinking that it was something inside the carb, and more along the lines that it was a fuel feed issue between the acc pump and the sending unit inside the tank. Its so confusing though because I have replaced nearly every componet of the fuel system between the carbs and the tank. Only thing I havent replaced is the sending unit assy. and the fuel tank it self. Im going to run an external fuel tank to see if the fuel filter stays full of fuel like it should, that will tell me if the problem is upstream of the carbs, or if its actully the carbs...
 
whether it fixes it or not, pull the carbs, and clean them..(internally) along with pulling the RAVES to clean those..(black caps on motor). When you disassemble the carbs, you'll see the springs I was referring to.

Your #3, in the first thread is contradicting..since you mentioned tiny filters and diaphrams..etc.
 
Yea I know I need to pull them but were visiting a lake out of town this weekend with some friends and I just dont have the time to do that right now even if it would fix it. As far as contradicting myself, I was misunderstood. When I said I replaced the micro filter and diaphrams/gaskets in the acc pump but had not removed the carbs and totally broke them down to do a clean I was telling the truth. I removed the acc pump with the carbs still mounted to the engine. I have also verified the rave valves but I can tell you that they are not causing the problem. Even if they were sticking, that wouldnt explain why I have such little fuel coming from the tank. I wish I could elaborate, however I still dont know the problem. Very wierd and frustrating. Ive spoke to alot of people on this one and everything they suggest, I have already tried (except removing and cleaning the carbs) but as I said before when the ski gets fuel, it runs great for the 15-30 seconds or so. I think Im just gonna try to run the external tank tomorrow and that will tell me for sure if its the fuel system upstream of the carbs or not.
 
inline filter

alright..not sure if it was mentioned in your "did list", but if ur ski has the white cylinder looking inline fuel filter...replace it, wit ha filter from any auto store. When the o-rings inside it goes bad, it'll give the symptom your having...suck'n in air.

ok, just read, you replaced it....if/when the internal filters that are inside the carbs are clogged, it'll run until your lines are emptied, then it'll "purge" the system, re-filling ur lines, that "whack" ski runs good again, then it'll repeat itself
 
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after reading your last post, I think the problem is most likely clogged internal fuel filters. the reason it runs fine for 15 seconds is because it is using the fuel it has built up. I suspect it will run fine for 15 seconds after it idles for a minute or two as well, again due to building up a usable fuel supply. when the filters are dirty, it can't get enough fuel through them to supply the motor when throttled up.
so, when you're starving your motor for fuel, you're running it lean which is dangerous and will cause you to burn up the top end. that's why you should check your plug color and your compression.
pulling the carbs is not difficult nor time consuming, even for a first timer. plan on 1 hour to remove, 1 hour to clean, and 1 hour to replace. it will run like new when you're done.
 
just a thought but i was having the same issue and when i replaced the lines the pulse line ended up collapsing on its self and couldnt pull the fuel properly, i know you said you verified its working but take a look at the hose and feel it to see if it is restricted on any of the curves that form in it.
 
Ok so here an update. By the way thanks for all of the helfull tips everyone.. I removed the carbs. Removed the second micro filter in the other carb I had never touched and it was clogged nearly shut. I was so happy. I was thinking great, Ill do a clean up on the carbs, put them back together and it should be fixed. Nope. When I went to start it, it started for a second and then eventully died. While it was running I was also observing the clear inline fuel filter, and it still didint look like it was filling up as fast as it should. Keep in mind, I have replaced ALL the fuel tubing including the pulse line off of the crankcase, both micro filters, all gaskets and diaphrams in the side pump housing on the first carb, and have verified that everthing between the tank sending unit and the carbs are flowing properly. The pulse line is pulsing and everything. One time I started the engine, removed the line off of the inline fuel filter and felt how much is was sucking... It was hardly sucking at all... This is driving me fuXXing nuts...
 
Maybe I need to verify the settings on the carbs?? I didnt touch them while I had them off so I didnt think I needed to mess with them.. If so does anyone know the stock settings on a 1997 GSX with the white 787 motor??
 
settings..

1997 GSX 787 (2)BN-40I, MAIN(jet)-142.5 PILOT(jet)-70 1.5n/s 23psi - 43psi LOW(lsa)- 1 HIGH(hsa)- (MAG-0 PTO-1/2)

with carbs apart, your fuel system drained, so it'll take a few hits of the start button, to get it all "primed". If the inline fuel filter aint filling, then bypass it for now, see if thats the problem..sometimes/alot of time, the o-ring inside it, goes bad, causing the fuel system to suck in air, causing a no prime syustem...
 
Sorry for being such a newb. Can you elaborate a little on the settings? All of my exp. is with fuel injection.. As for the fuel system I was expecting some delay because of draining the system. The stock fuel filter with that o ring has been removed. Im now using an inline style from an autoparts store (pn F20011). Once it did start it would barly run and I was giving it a little gas yet it still was hiccuping and then died. now it wont start. Removed plugs and there wet and black. All Im sure of is before I removed them it would start fine even though that clogged micro filter was in the carb. I replaced it, put the carbs back on and now its doing this.
 
high speed adjuster, should have a black cap on each carb. Low speed adjuster looks just like the idle adjuster.."T" screw, . Double check the fuel lines, make sure they're installed properly..real easy to mess them up, when replacing.
 
timmyboy76 said:
high speed adjuster, should have a black cap on each carb. Low speed adjuster looks just like the idle adjuster.."T" screw, . Double check the fuel lines, make sure they're installed properly..real easy to mess them up, when replacing.
Click to expand...

Ok sounds good. How many turns out on the low and high side ajusters? Also I am picking up some new plugs today. Im almost sure I flooded the engine after reinstalling the carbs. Plugs were wet and black so I suspect there fouled out. If all that works and it runs fine out of the water , I guess Ill have to wait till get in the water to see if the fuel starvation has been fixed...
 
slobra300 said:
Ok sounds good. How many turns out on the low and high side ajusters? Also I am picking up some new plugs today. Im almost sure I flooded the engine after reinstalling the carbs. Plugs were wet and black so I suspect there fouled out. If all that works and it runs fine out of the water , I guess Ill have to wait till get in the water to see if the fuel starvation has been fixed...
Click to expand...

can anyone tell me the stock settings for the low and high settings of the carbs on a 97 gsx w/ the white 787 motor? PLEASE!!
 
I feel like a newb.. I get it now. lsa =low speed ajuster hsa= high mag = rear carb pto= carb with fuel pump.. right?
 
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