1999 Sea Doo GTX RFI - Stalled an now won’t idle

[LIBoater]

Ski has been running great with the new engine, new starter and rebuilt water pump… however, this weekend, while out riding, she stalled at idle, then was tough to start and wouldn’t idle… she’s been running great and happily idling at around 1400rpm (from memory)… I have been super-careful not stressing the engine during break in and I have made sure the gas in the tank is 40:1 even though I primed and bled the pump… wanted to make sure she’s getting enough oil… I haven’t pulled the plugs, yet, but, as I sit here reflecting I wonder if I “over-oiled” her and the plugs fouled?… any suggestions as to what to test next? Thanks in advanc!

 

[POPPS]

There is no water pump,,,if it’s a 2 stroke,,,which it is……over-oiled,,,no,,change /look at the the plugs to start,,,are the injectors injecting,,,check compression,,,load test the battery,,,is it charging?

 

[LIBoater]

There is no water pump,,,if it’s a 2 stroke,,,which it is……over-oiled,,,no,,change /look at the the plugs to start,,,are the injectors injecting,,,check compression,,,load test the battery,,,is it charging?

Thanks for the response, yup my bad I meant rebuilt jet pump not water pump… no matter, in answer to your points:
- will put new plugs in and see if that helps? I haven’t pulled them yet, but that will be 1st on the list
- I haven’t checked compression but it’s a brand new (refurbed) engine so would be shocked if that’s the issue?
- battery is brand new and charging well and I put it on trickle charge overnight to be certain
Will update after trying new plugs

 

[POPPS]

You can trickle charge any battery to death,,,and then set it fall on its face under load…check compression,,,give us a look/pic of the plugs.

 

[LIBoater]

You can trickle charge any battery to death,,,and then set it fall on its face under load…check compression,,,give us a look/pic of the plugs.

Will do… hope to head back to the boat on Weds and pull the plugs… I went for a pretty beefy battery (NOCO Lithium NLP20, Group 20,... https://www.amazon.com/dp/B091P96DDB?ref=ppx_pop_mob_ap_share) in the hope that I wouldn’t have cranking issues… will try and dig out my compression kit and take that to the boat Weds too… stay tuned.

 

[LIBoater]

Managed to get to the boat... pulled the spark plugs, which looked OK (see attached)... changed for brand new anyway... forgot compression tester, but she started fine, but stalled again... she won't idle above 730 rpm (which is where she dies)... if i hold the throttle open at 3,000rpm (idle speed out of water I believe) the engine runs sweet, so I'm assuming I just need to adjust the idle screw?... not sure what would have caused the idle to drop so significantly (I think she idled at about 1400RPM in the water last time I checked... any thoughts here? Simply adjust idle screw, or something else?

 

[etemplet]

Did you say you put premix in the fuel tank? The RFI definately does not need premix. I was told by the fuelinjectorman.com that premix wouldn't hurt the injectors. The premix may be causing a problem problem you may have is too much oil in the fuel for the injectors. I'd pump the tank out and put straight fuel in there. Check your fuel pressure while running. Good Luck !!

 

[POPPS]

Do you have proper compression?,,,is the fuel pump up to snuff?

 

[LIBoater]

Did you say you put premix in the fuel tank? The RFI definately does not need premix. I was told by the fuelinjectorman.com that premix wouldn't hurt the injectors. The premix may be causing a problem problem you may have is too much oil in the fuel for the injectors. I'd pump the tank out and put straight fuel in there. Check your fuel pressure while running. Good Luck !!

I was told by Mel at 5 Star PWC (who supplied the new engine) that I should pre-mix the first couple of tanks until we know the oil pump is working as it should and to assist the break in of the new engine… will stop premix now, as I may undo all the good work fuel injector an did refurbing my injectors!… That’s what I meant by “over-oiling”… going to put a can of this in to the fuel to give it all a good clean (Advance Auto Parts - Down for Maintenance) she’s been running great, so I’m sure that’s the issue

 

[LIBoater]

Do you have proper compression?,,,is the fuel pump up to snuff?

i installed a brand new fuel pump last summer, so should be ok… will try and remember to take the compression tester this weekend!

 

[mikidymac]

Do not add any fuel additives except marine Sta-bil.

 

[LIBoater]

Do you have proper compression?,,,is the fuel pump up to snuff?

Ugh… painful as it seems, you’re right… I did a compression test and the back cylinder is down to 30psi … just spoke with 5 Star Services (super-helpful)… engine is covered under warranty (that’s the good news)… the bad news is I have to pull it and send the engine back… the other good news is our Wake Pro (ordered Sept last year) was finally delivered on Saturday, so we are not ski-less… I suspect I will get the engine fixed and sell the old girl… any ideas what I might get for her with a new engine, jet pump, fuel pump, starter, battery, stator, seat and all the other $$$$$ I’ve put in to her?

 

[etemplet]

Popp's knows his shiznit. Always check compression FIRST. Then move on to other things before you end up chasing your tail. I'm glad I can do my own work it takes these shops forever to do the work. Day and a half and I'm back running.