Super Jet Engine dies under load

[Pablo]

I'm sending out thanks to my riding buds for checking my ski when I'm outta town. Otherwise it woulda happened on me when I got back myself. How's the knee John?

I put it up last weekend and it started, ran, and rode just fine. Prior to running it that day I increased the low jet size on my carb to help clean up some fuel starvation issues on the bottom end. After this change it worked great. Ran it that day just fine and haven't touched it. I asked my riding buds to check it mid week since I'm on vacation and didn't want to come back to a dead battery.
From the report I got, my ski started and ran fine/normal right off. It ran good for about two minutes and then died on the water. It was able to be limped back about half way then died completely. It was checked out on my dock and all looked normal. He said it started and revved normal on the dock so he put it back in water. It ran normal for another 15 secs then died out again...suddenly and wouldn't restart. I was told it felt hot, like it had been run all day in July. Cooling plumbing was fine last time I ran it but don't know how it was pissing during this run. It's a new mag pump with dual cooling and a brand new wsm/plastic lined wear ring. That's all the info I have right now. I was told the battery seemed fresh for starting and turned over fine on the dock. Gonna give it a look when I get back but extra thoughts are welcome.
Add any points I missed John.

 

[Pablo]

Was thinking. I'm now running a Prok flame arrestor. My last set of Proks the center cones fell out at different times and choked the carbs causing nearly the same symptoms. It doesn't explain the engine temp issues though. I like the looks of them, but Proks are junk IMO.

 

[tor*p*do]

dual cooling and a brand new wsm/plastic lined wear ring.

I hear these can slip and cover the cooling water port in the pump cutting off all cooling
may want to check that

 

[Waternut]

The Prok air filter looked fine. At first I thought it ran out of fuel because that's what it felt like but the primer was still pumping fuel and it wasn't starting. When I say "limped it back", it would only run just off idle for a few seconds and I had to restart it a couple times. I want to say the pissers were flowing but I can't remember for sure.

Every time I took off on it, it ran and revved fine and then at some random moment, it was like you hit the stop button and it just quit. Could be as simple as a loose wire connection but I don't know how you have your electrics setup. Even more odd... When I went to put the ski back on the lift after giving up, it was running, revving, and idling fine in the water. I think your ski just likes the lift....

 

[sportfish258]

Maybe it just gets home sick .... my bet is electrical

 

[Pablo]

Why hot?

 

[tor*p*do]

Why hot?

see #3

 

[Waternut]

I hear these can slip and cover the cooling water port in the pump cutting off all cooling
may want to check that

How is that possible? The cooling lines are located in the middle of the stator...not in the wear ring.

Gregg, I don't know if I'll have a chance to ride it again before Friday so you may be tinkering before I can. I'll keep you posted if I can though.

 

[Pablo]

Back from vacation and I'm back on my ski. It starts, idles and runs as it should 98% of the time. I'm having an issue that I'll bet is electrical...but where to start?

Symptom:
Fires up smooth and will take off, but if the throttle is blipped and completely let it return to idle it will die like the lanyard is disconnected. On wide open runs or mid-throttle runs it's fine...even putting up to my dock is fine, but if you blip the throttle it will completely shut down.

Things checked:
I gave the start/stop a run through two weeks ago and it checked out fine on ohm meter. Ski will restart without problem...1 second after cutting off.
Ebox was gone through completely on rebuild about a month ago and has been run maybe 3 hours.
All connections are fresh with dielectric.

I'll double check my ground tonight.
I was wondering if anyone's had or having symptoms like this out of their Epic?

 

[McDog]

What battery are you running? If it's one of the DEKA ETX9 types maybe it is dropping the voltage below a level the EPIC will accept. Seems like Matt E had this issue with a FLAME.

 

[Waternut]

What battery are you running? If it's one of the DEKA ETX9 types maybe it is dropping the voltage below a level the EPIC will accept. Seems like Matt E had this issue with a FLAME.

That's a good point... I noticed that the ski always ran after the battery had reached a resting voltage (me swimming it back) but when I started it up immediately after starting it up again, it would die quickly. Then today when it was struggling, you let it sit on the beach for a few minutes and it worked again.

 

[QJS]

This was true of the earlier Flames not Epics.
Chris

What battery are you running? If it's one of the DEKA ETX9 types maybe it is dropping the voltage below a level the EPIC will accept. Seems like Matt E had this issue with a FLAME.

 

[QJS]

Are you sure this is electrical? The symptoms you describe make me wonder if you may have a part blocked low speed jet or similar. I don't think it would be the Epic but you could also try the stop circuit to make sure the white is not simply shorting somewhere.
Chris

Back from vacation and I'm back on my ski. It starts, idles and runs as it should 98% of the time. I'm having an issue that I'll bet is electrical...but where to start?

Symptom:
Fires up smooth and will take off, but if the throttle is blipped and completely let it return to idle it will die like the lanyard is disconnected. On wide open runs or mid-throttle runs it's fine...even putting up to my dock is fine, but if you blip the throttle it will completely shut down.

Things checked:
I gave the start/stop a run through two weeks ago and it checked out fine on ohm meter. Ski will restart without problem...1 second after cutting off.
Ebox was gone through completely on rebuild about a month ago and has been run maybe 3 hours.
All connections are fresh with dielectric.

I'll double check my ground tonight.
I was wondering if anyone's had or having symptoms like this out of their Epic?

 

[Pablo]

Chris,
U might have hit it right off. I changed out my low speed jet and really didn't even look at it before I put the new one in.

 

[Big Kahuna]

I thinking jetting or something with the needle/seat/spring. Like it flooding the motor out at low speed, high speed it can burn it.

 

[McDog]

Wouldn't start today. He ran the battery dead trying then gave up and put the battery on a charger.

 

[D-Roc]

any spark?

 

[Pablo]

Yes to spark. Ski would start and idle before i did the following:
- pulled the carb to check the low speed jet.
- flushed both jets and needle/seat clean.
- Checked the diaphragm it was good and the pump spigot was clean.
- I shot a little carb cleaner through all the jets and the needle/seat while I had them out.
- lightly sprayed the exterior surfaces of the jet and needle orifices too.
- reassembled the carb. Installed it with fresh fuel. A couple of primes and no fire? It will turn over fine and makes good spark at the plugs but no catch??
Eventually I was getting it to try and start but it would just rumble maybe a few revolutions but it would never catch and then my battery went weak. I've got wo good batteries charges and ready for some action tomorrow. I did notice the carb seemed (to me) to be dumping out a lot of fuel during all my start attempts. Can I be too far out on my low speed needle and flooding the engine with too much fuel? I've never seen it before on any of my sj's but it's in my head. What else?

 

[D-Roc]

anything is possible, if you have good spark, good compression, and fuel going down in, timing would be my next guess. not sure as to why it would be out all of a sudden. or fouled plugs from lots of fuel. but you said spark is good. no pop-off test on the carbs? if the needle and seat are leaking i have flooded my cases with fuel and it would not start. after lots of cranking and head scatchin, i got it to fire but it had some flames shooting up the pulse lines, that can't be good but it was fine.

 

[Pablo]

I did change timing with computer on my epic. I had waxheads real aggressive curve loaded up and changed to a less aggressive curve, but not night and day different. The ski did fire and ran yesterday after I made the change to the curve, so I doubt that's it but I was way out on the low speed needle to accommodate wax's curve that needs alot of fuel down low. I ran my ski on the lift and didn't get a chance to check how it responded with the new curve, so I'm still fat on that needle with a larger jet.