Dirt in gas on my HX

[bawray]

I bought a 1997 HX back in the spring...the last year it was registered was 2015 so it has pretty much sat in the woods for 5+ years. I have worked on it all summer and taken it out 6 or 7 times. One ride will be great but the next ride will have an issue. Now, it is dirt and grit in the fuel. I am not sure where it came from but I think it was a local gas station. Anyway...dirt/grit is getting past the fuel filter/water separator and causing issues. I have removed the cards twice, cleaned them, and replaced them only to have it happen all over again after 2 rides. There isn't alot of grit/dirt in the bowl but there is definitely some there again and I am sure there will be some in the carb filters and inside the carb as well because the HX will run great then just fall on its face when the fuel gets cut off by somewhere. I have drained the tank twice with a siphon but I haven't put rags inside or anything else to REALLY clean up the tank. I have strained the fuel each time and I really didn't find my dirt/grit in the strainer so I think it is OK only to have it happen again. I read the thread at Link and it seems my only two choices are to 1) remove the motor then the tank (to clean it) or 2) siphon the gas out and put rags and fresh gas in the tank to try to clean it. I know an inline filter is an option as well but I have read mikidymac's post and if he says "no" then I will trust his experience and not put in an extra filter.

But...I am worried that I am so focused on gas/carb now that the issue may be electrical. Unlike before this time pulling the choke would kill the motor. I just looked insdie the carbs and they seem to be pretty clean...no obvious dirt/grit/crap in the filters or inside the carbs. This last ride I experienced something a little different. I was just going down the waterway at 3/4 throttle and I felt a quick "tug" like the motor missed for 1 cycle. Then it ran well for a while. Then it would get worse. Then after about 1/4 tank of fuel it wouldn't get up to half speed at best. Surging then nothing then it would be fine then surging again and again.

I am wondering if I should start replacing components like the rectifier, coil, electric module, spark plug wires, etc. I am really tired of chasing this thing all summer.

I would love to try one electric component at a time but my biggest problem is testing. For me to put the ski in the water and try it out is a big ordeal. Not easy to test something then put back on the trailer and work on it in the parking lot...in 95+ temps...in the sun.

Any suggestions would be great!

 

[Rabid]

On my 99 there was a lot of sand and a rubbery substance that I had to get out. I removed the filler hose and the baffle. I found a 12 inch piece of steel tubing that I used on the end of my siphon. It allowed me to remove most of the material and fuel. The tank then sat for a couple of days to evaporate out the gas where the tank was dry and I would put a loop of duck tape on an end of a dowel and tap the bottom of the tank and I was able to removal all the foreign material. The tank has to be dry. Also get one of those spring grabbers where you can pick out the larger chunks and tape that has fallen off the dowel. OReilys has them for 12 bucks.

 

[POPPS]

Not sure of the hx tank...my method is to drop the front 3rd wheel...this brings all the gas to the front,,,,,then i syphon out as much as i can,,,then i take a large towel,,,force it the bottom of the tank,,,pull it out and rinse it into a large bucket,,.i repeat the cycle till the towel does not come out soaked,,,the air drying is a good idea,,,if it is a 4tec i am able to put my hand into the large fuel pump hole,,,and get the tank hospital clean.

 

[bawray]

Thanks. I will work on drying out the tank today. The HX tank is way back under the seat with poor access so it will be difficult. I can put anything wider than a couple of inches down in the tank and it will be very iffy if I have to fish anything out but I already have the grabbers and I will see what I can do about finding the right towel/rag/wooden dowel to get down there and really get everything out. Not going to be fun...

 

[Rabid]

Thanks. I will work on drying out the tank today. The HX tank is way back under the seat with poor access so it will be difficult. I can put anything wider than a couple of inches down in the tank and it will be very iffy if I have to fish anything out but I already have the grabbers and I will see what I can do about finding the right towel/rag/wooden dowel to get down there and really get everything out. Not going to be fun...

Can you take a pic?

 

[POPPS]

I believe you have to disconnect the seat and raise it into the air,,,i believe,,,if its the same as the XP LTD's that i have at our shop.,,could be wrong,,,that would give you nice access,,,

 

[mikidymac]

No, the HX sending unit is on the front of the tank. You might be able to get it out around the pipe then siphon the gas and trash out.

 

[bawray]

Update. Upon more reflection I decided to remove the carbs to check for clogging or at least signs of some debris getting in there before pumping out the tank and cleaning it again. Both carbs were perfect. No dirt, no grit, no anything except for gasoline. The two tiny filters were clean as a whistle.

So, I have to give some history here...I bought this ski in February. I have rebuilt these carbs twice now and both times I did a pop-off test. Both times both carbs would pop at 60 psi which is at the very upper limit for my 97 HX. The thing is...this was my first rebuild of jetski carbs...my first time dealing with "pop off". When I first started checking the pop-off I used my excellent mountain bike shock pump, a valve from an old tube, fuel line, zip ties, and hose clamps. I clamped the value inside a 1/4 fuel line and connected it to my pump and the other end to the carb. Worked great. Then I zip tied the 1/4 fuel line to the carb. I keep getting a leak and the system would never build pressure so I replaced the zip ties with clamps and it seemed to work. I was never totally confident in this setup. Therefore when the carb would pop and drop 10 lbs and then slowly continue leaking down to zero I just thought my pump setup had some small leak and I disregarded the slow "leaking" after the pop (I thought maybe I am not spraying enough WD-40 maybe???). I should have followed Mikidymac's procedure to the letter but I didn't. I just kinda forgot about this slow leak. But, it has always stayed in the back of my mind. In the meantime I have checked the pop-off on my XP carbs and there was no slow leak from the "system" of pump and hoses. So, last night I noticed the same slow leak down again on the HX mag carb. It would pop at 60, immediately drop to 50 and continue slowly leaking down to zero. This time I really wanted to find the leak. Turns out the air is coming from the diaphragm and leaking out the gap between the two blocks of the fuel pump. And...the diaphragm actually has a bend or kink in it at the location of the leak (during the last rebuild I noticed the diaphragm had the same bend and replaced it with a new one now the new one is identically bent). I disassembled the pump body and checked the two blocks and there is NOTHING there to cause this bend. Nothing. I really don't understand how this is happening unless the high pressure is somehow kinking the plastic diaphragm and the metal blocks are a little warped possibly??? But, this has definitely been a problem from day 1. I have replaced the fuel baffle and check valves this summer because both were causing problems (especially the baffle). But, I have continued to fight the problem where the ski will run great for 15/30 minutes then just start having issues with fuel starvation.

I have 2 more sets of carbs (off 2 old HX's I have) and I robbed these two blocks off of one of the other carbs, reassembled using the diaphragm from the old carb because I don't have any more unbent new ones. Now the system is AIR TIGHT. It pops at 60 psi. Drops about 10 psi and holds there. For an hour! I actually went in an bent the tabs a little to get the pop off to 55 on both carbs because 60 was right on the limit.

I will reassemble today or tomorrow and try again.

 

[bawray]

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View attachment 56182

Nice clean hull! I wish I could get mine this clean.

 

[Rabid]

Can you lightly wet sand the block on a super smooth surface to clean them up?

 

[bawray]

 

[mikidymac]

Never seen that before. Really weird.

 

[bawray]

This is the diaphragm I took off last week. Notice they have the exact same bend/crimp in them. How? Why? I will post the blocks next.

 

[bawray]

 

[bawray]

 

[bawray]

And...there wasn't anything strange about the o-ring...I honestly don't remember but if there was something stuck to it seems like I would have noticed and removed before I replaced the old diaphragm with a new one. I just can't figure out what was bending/crimping the diaphragms (I don't have the first one I replaced but it seems like it was damaged just like these two...I just don't remember for absolute sure because I was just taking out the old stuff and replacing with new and I didn't take note of this).

Hoping to take the ski out today and test it out with the new blocks/diaphragms.