97 GTX - Am I too Lean? - High RPM Power Loss - At Lake

[digital sol]

Thanks Soccerdad, unfortunately I don't have one here but I got it started pretty quickly. It started quicker even with all that air in the lines and no fuel than it did this time last year after the shop said it was good to go LOL

I got it out for another ride and same issue. I can see the return line has a few bubbles "tiny" however the feed line has lots of air bubbles. Also when I coast at low rpm the line is full then when I got WOT it depletes and there is quite a lot of bubbles/air coming through the line. The boat has about 3-5 gallons of gas in it. I didnt fill the tank up entirely until I knew the ski was running properly. I dont recall every having this type of issue from lack of full tank either way.

What would cause air in the system when running the line directly from the on/sending unit to the carb? The hose is clamped very tight at the sending unit so I dont think its getting air from there. I mean thats basically the last thing to rule out if its getting its fuel directly from the tank and still putting air in the lines. I assume some small bubbles here and there is normal but cant imagine seeing the line run dry or large bubbles/spaces in the lines while giving it more throttle is normal.

I will mention during my restoration I pulled the fuel tank, cleaned it inside and out, replaced the magnet deal inside the sending unit and remove the inside fuse. This seemed to have fixed the issue where my fuel tank always reads low but wanted to mention it.

I can try and shoot a video later the lake is about to be flooded with boats for the holiday but its usually glass by 6-7pm.

Edit: I also did NOT get a hiss or suction when removing the gas cap again today. I did check its seal and its installed. Figured i would mention this as someone said in a thread online if the fuel tank is working properly there will be a hiss when you remove the gas cap.

 

[soccerdad]

Sounds like progress. Was it doing it on reserve and on before you went to the single line.

 

[Mekanix]

Very nice !

Ok so next thing to try is remove the line from the ON and connect it to the RES and try again.

I have seen three things with these sending units.

1 the outlet nipples get bent or cracked even from over tightening the clamps.
2 repairing the f1 fuse accidents causing the line inside the tube to get nicked and let air in.
3 the cracked nipples only apear when the clamps are tight.

For the tank hiss. Have a look at that vent line 3 way setup. The line going back goes to the inlet check valve. Remove the side cover or pull the valve out of the gromet and blow into it.
that should fill the tank with air and then it should hiss when you open the cap.

If not. Find the leak. Either its the other valve that is bad or im leaning towards you have a cracked fittin on the sending unit.


Err. I just found one unit where the top part with the 4 nipples is completely seperated from the base....but the boot was holding both parts together....




If the RES test does the same thing. Likely thats whats happening.
Another way to test is to "carefuuly" use another fuel source or spare tank.

Just remove the clear line from the sending unit and reconnect the black ON line so it doesnt spill fuel inside the hull. Then take that clear line that goes to the carb and place it into a remote tank that cant spill.

Bring a fire extinguisher with you and keep in mind static discharge!.

 

[digital sol]

Sounds like progress. Was it doing it on reserve and on before you went to the single line.

It was doing it on reserve as well.

 

[digital sol]

Very nice !

Ok so next thing to try is remove the line from the ON and connect it to the RES and try again.

I have seen three things with these sending units.

1 the outlet nipples get bent or cracked even from over tightening the clamps.
2 repairing the f1 fuse accidents causing the line inside the tube to get nicked and let air in.
3 the cracked nipples only apear when the clamps are tight.

For the tank hiss. Have a look at that vent line 3 way setup. The line going back goes to the inlet check valve. Remove the side cover or pull the valve out of the gromet and blow into it.
that should fill the tank with air and then it should hiss when you open the cap.

If not. Find the leak. Either its the other valve that is bad or im leaning towards you have a cracked fittin on the sending unit.


Err. I just found one unit where the top part with the 4 nipples is completely seperated from the base....but the boot was holding both parts together....




If the RES test does the same thing. Likely thats whats happening.
Another way to test is to "carefuuly" use another fuel source or spare tank.

Just remove the clear line from the sending unit and reconnect the black ON line so it doesnt spill fuel inside the hull. Then take that clear line that goes to the carb and place it into a remote tank that cant spill.

Bring a fire extinguisher with you and keep in mind static discharge!.

Alright thanks, I will try these out tonight/tomorrow morning. I am going to call a shop as well and see if they have a replacement sending unit available. I drove by one the other day that had 3 skis just like mine so I am assuming they might have some spare parts. They are closed today but I will call first thing tomorrow morning.

The valve you are referring to is the one going out the right side/passenger side of the ski near the center area right? Just checking as there is also a valve or something connected at the front of the ski on the same side that's coming off that three way splitter/vent config as well.

 

[Mekanix]

It was doing it on reserve as well.

I would also suspect the fuel selector is bad if it starts working well on reserve when connected directly.

 

[Mekanix]

The valve you are referring to is the one going out the right side/passenger side of the ski near the center area right? Just checking as there is also a valve or something connected at the front of the ski on the same side that's coming off that three way spliter/vent config as well.

Right. The one on the back center is the inlet and is just a simple check valve.

The one that exits underneath the rail is a pressure pop off valve. If the thank over pressurizes this will pop and let the pressure out but it will close as well so no fuel spills out.


On the sending unit did you see where it says ret, res, on and vent? Were any of the lines mixed up in the past?

I've had one machine run when it was set connected to ret or vent when the tank was almost full until it acted the same as yours. Then died but would run again.

 

[digital sol]

Right. The one on the back center is the inlet and is just a simple check valve.

The one that exits underneath the rail is a pressure pop off valve. If the thank over pressurizes this will pop and let the pressure out but it will close as well so no fuel spills out.


On the sending unit did you see where it says ret, res, on and vent? Were any of the lines mixed up in the past?

I've had one machine run when it was set connected to ret or vent when the tank was almost full until it acted the same as yours. Then died but would run again.

Ok great, I am fairly certain the lines are all correct. I did verify the ret & on lines were correct when I swapped lines over to go directly to the carbs and return. The other two I will confirm did not get mixed up when I get down there tonight. I was pretty ocd about label'ing those but but maybe two of them got mixed up. Ill double check.

I did replace the fuel selector with a brand new unit just to be safe while doing all the other work a few weeks back. When everything was hooked up to the selector valve even moving it to res did the same thing at high rpm's. Ill move the carb feed line to the res nipple on the sender unit and give it a go as well as check the other two nipples/lines are setup correctly.

 

[soccerdad]

I am completely on board with the comments from Mechanix. Sounds like something is wrong with the fuel baffle. A crack, or something wrong there. With your direct plumbing, no air should enter that fuel line at all. If it did, you have a crack or hole in the baffle. The remote tank idea will prove it out, or if you can get another baffle to test, that would be great. I have one I could send up to you, but you would be down for a few more days. I would focus on the air/good fuel supply and not on the tank hiss right now. Honestly, I never hear any hisses or venting. I doubt that is your problem. The venting side just lets air into your tank so it does not create a vacuum as you use fuel, and also lets out air if the tank pressurizes because of fuel expansion. You can blow out those vent fittings with an air gun to make sure they flow air. But again, I do not think that is the problem.

I use an old plastic lawnmower tank for limited remote tank testing that I have done. But you could do it with a plastic bottle with your feed line stuck in it all the way to the bottom. You can let your return line just keep returing to the main tank for the test. Again, just be careful.

 

[digital sol]

I am completely on board with the comments from Mechanix. Sounds like something is wrong with the fuel baffle. A crack, or something wrong there. With your direct plumbing, no air should enter that fuel line at all. If it did, you have a crack or hole in the baffle. The remote tank idea will prove it out, or if you can get another baffle to test, that would be great. I have one I could send up to you, but you would be down for a few more days. I would focus on the air/good fuel supply and not on the tank hiss right now. Honestly, I never hear any hisses or venting. I doubt that is your problem. The venting side just lets air into your tank so it does not create a vacuum as you use fuel, and also lets out air if the tank pressurizes because of fuel expansion. You can blow out those vent fittings with an air gun to make sure they flow air. But again, I do not think that is the problem.

I use an old plastic lawnmower tank for limited remote tank testing that I have done. But you could do it with a plastic bottle with your feed line stuck in it all the way to the bottom. You can let your return line just keep returing to the main tank for the test. Again, just be careful.

Thanks. I am going to rig up a gatorade bottle or something simple just to take a few second test. I went ahead and ordered a new sending unit & relief valves and had them shipped fastest method possible. I hate to spend the $$ on a sending unit like that but I really want to enjoy it while I am down here on vacation. I ordered from OSD so with any luck they will be here in a day or two.

I am onboard with you guys entirely, it seems like my sender unit is most like the culprit. Most likely something I did wrong while fixing the original sender unit fuel guage issue as I did open it up for that fix etc. Ill give it a quick try later when it cools down with a gatorade bottle for a quick test

I am going to drill the cap & seal a fitting on it.

 

[soccerdad]

Make sure it has a vent hole

 

[digital sol]

Make sure it has a vent hole

The replacement baffle/sending unit? I presume we are referring to a small hole on the side of the sending unit/baffle? I remember seeing one on the factory baffle when I had it out a while back. Will do & thanks again for all the help. With any luck I will have the parts by Thursday so I can enjoy the ski a few days. Thanks everyone! Ill post back once i get the parts and try it out!

 

[Mekanix]

He means the gatorade bottle lol
Justso it doesnt vaporlock.

Keep in mind the nature of the fuel pump and return line. It will suck all the fuel out of the bottle and put it into the main tank through the return line.

But it might run long enough to show you that it works.

 

[soccerdad]

Sorry. I am confusing you. The baffle is the real name of the tube with the float in it that the fuel comes from that you are calling the sending unit. I was just making sure you add a vent hole in your Gatorade bottle fuel tank so it will let your fuel pump suck the fuel out of it. When you said "seal a fitting on it" made me make the comment.

 

[soccerdad]

Oh- beaten again.... yep, what Mekanix said.... (but he does have a typo - it returns though the return, not reserve line... That is what he meant to say )

 

[digital sol]

Oh- beaten again.... yep, what Mekanix said.... (but he does have a typo - it returns though the return, not reserve line... That is what he meant to say )

Oh ok haha, yea that makes sense. Thanks fellas! Yea it should be enough time for me to at least try it out. I have a lift for the sea doo but its a pain in the ass to work on it while on the lift because its on the back of the dock. Luckily I can launch it and put it back on the trailor right next to our dock so it hasnt been too bad working on it. Hoping parts are here Thursday

I will know this thing like the back of my hand by the time I am done !

 

[Mekanix]

Smart phone... dumb fingers.

 

[digital sol]

Hey guys, I never did end up swapping in another tank to test with but I replaced the sender unit and issue is still occuring. I am going to replace those two breather vents/valves as well as the description on OSD site indicates the fuel system needs those to function to provide properly suction/vacumm for the pump. I will report back shortly.

I will say the sender DID need to be replaced. The repair I did to fix the fuel sensor was the root of the issue. I used plastic weld to seal the unit back up and the gas dissolved the sealer and was breaking it down. I had technically 3 filters between the tank and the carbs besides the time or two I took it out with running the line straight to the carbs so hopefully I didnt gum anything up in the process :/

I still had the issue though after swapping the sender unit so I am going to swap those valves and retest. Worst case I am going on a cruise on low rpm to enjoy the ski a bit before I head home.

Edit: During the test the max rpm i hit was about 6200. Most of the time it wouldnt budge over the 5k mark but I had a passenger with me.

 

[digital sol]

I replaced the pressure valves and same results for the most part. The fuel guage was working with the new sender unit and then it started reading fuel low with 10+ gallons in the tank.

Basically at this point it fires right up, idles great, runs great low rpm but cant hit over 5k. Unless I hit a wave or turn her wide to get some air under the ski it wont get past 5k rpms. I took a long cruise at 4k rpm and it drove fine just not much fun cruising the entire time LOL.

Anywho at this point I am done with her. I will tow it in somewhere before I leave Sunday & pick it back up next vacation. Hopefully the float in that brand new sender unit isnt an issue already. I can always take the float from my old sender unit worst case but its brand new. I put maybe 6 minutes on it before it started reading low fuel. It was showing accurate gas up until then.

Its odd I cant even hit 6k rpm now while loading it up on low rpm first but maybe the carbs or something got gunked already from the issue noted earlier. Who knows at this point just out of time and patience to work on her. Hopefully the shop can figure it out without costing me a kidney since I already spent a ton of time and money fixing her up over the winter

 

[soccerdad]

Man that sucks! I wish we were able to help more. Sorry.

 

[digital sol]

Well the ski is at the shop for a couple weeks now and no dice. I am starting to get a bit worried about it. They called today and said they think my aftermarket impeller is the problem and said the fuel system is working properly.

Is that even possible? My impeller was reccomended by group K. I dont see how the impeller would lose 2K rpms

I think they are going to put the stock impeller back on it and retest. They said it hits 6k+ out of the water etc as I mentioned before but in water it hits the wall around 4.5k-5kish as I originally mentioned.

 

[Mekanix]

That's posssible. How fast was it going at 6k?

If the pitch is too steep the motorwill stall out before reaching max rpm.

What's the part number and pitch of the impeller?

 

[digital sol]

That's posssible. How fast was it going at 6k?

If the pitch is too steep the motorwill stall out before reaching max rpm.

What's the part number and pitch of the impeller?

I cant get it to 6k unless I put the ski on its side or hit a wave and rev it or start it out of water and rev it. While in water it only hits 4.5k-5k. Originally sometimes it would blip to 6k for a second then die down to 4600-5k rpms but the speedo dosnt work on it. If you rev it to 6K in the air and hit the water it dies down immediately. Also wave jumping was kind of impossible because when you mash the throttle it hit that wall at 4-5kish rpm's and never really gave you that oomp to get up and off the wave. I just ended up cruising it for the weekend before towing it into the shop.

I am just worried now they dont know what the actual issue is and I dont want some huge bill and a ski that still dosnt run right in the end. I am sour from all my bad previous dealings with any shops but was hoping this time it was a simple in and out fix.

I am using the Solas Concord 15/23 Impeller

I got the recommendation straight from Group K. I know its different than the manufacturer site but group K said in all there testing on my make and model ski that prop had the best overall results. If that recommendation is straight wrong and that's all it is great I just don't want the ski being taken apart & parts swapped around without good reasoning behind it.

Also incase you missed my resto thread it has the following new/rebuild or replaced although I am more curious about this impeller thing first.

-everything inside the pump via OSD oem rebuild kit
-water regulator
-rave valves
-worx intake grate
-aftermarket OSD rectifier
-oem carb rebuild kit

 

[Mekanix]

Ok. That is the impeller im using on my gsx. And the gtx is heavier. You should be hitting 67-6800 with that impeller no problem but the main difference between that and stock is that the solas will grab faster and hold better than the stock. Also less cavitation. I think their recomendation is good. But if doesnt mean the impeller wasn't defective and pitched wrong. Ive had good luck with them.

So if we can eliminate those things you have done and the pump/impeller.

Rotary valve timing and ignition timing are the next things id look at.
If the flywheel moved and stripped the woodruff key that would retard the ignition timing and basically give you no power reguardless of how much fuel you pump into the engine.

If the rotary valve timing is off and closing too soon you would run out of steam quickly before reaching top end power.

 

[digital sol]

Ok. That is the impeller im using on my gsx. And the gtx is heavier. You should be hitting 67-6800 with that impeller no problem but the main difference between that and stock is that the solas will grab faster and hold better than the stock. Also less cavitation. I think their recomendation is good. But if doesnt mean the impeller wasn't defective and pitched wrong. Ive had good luck with them.

So if we can eliminate those things you have done and the pump/impeller.

Rotary valve timing and ignition timing are the next things id look at.
If the flywheel moved and stripped the woodruff key that would retard the ignition timing and basically give you no power reguardless of how much fuel you pump into the engine.

If the rotary valve timing is off and closing too soon you would run out of steam quickly before reaching top end power.

Well the shop called and basically said they have no idea what the issue is. I asked if they checked the timing and they quoted me $400 to do so...They said they checked the carbs and everything there seemed fine. At this point I dont want to keep the ski at there shop as its clear if its not an easy fix they don't plan on really working on it. I am really curious how much they will end up trying to charge me thus far for the troubleshooting they did.

With that being said....anyone live around Table Rock Lake or know a shop that know's there stuff in the Springfield area? If not I will be driving 3.5 hours to pick the ski up and towing it home to STL to work on it myself. I really just wanted to drop it off and get it back in running order but I have literally NOT ONCE had a shop take a ski or even a car in for that matter and do quality work. It seems like 99% of the shops just want the wham bam jobs and quality of work is poor. Hell the last time I took a car into the dealership *under warranty* it came back missing half the engine covers and bolts for them :/ *a dealer that charges upwards up $150 an hour*

End of rant, just frustrated. My tools/garage is here in stl. The place at the lake dosnt have any type of garage for me to work in so its kind of a pain in the butt to get anything done down there but I also don't have a lake nearby here but I could probably find some place close by to test at *river or something*.