2003 Sportster No Start Mystery

[Sailorboy58]

This week I bought a 2003 Seadoo Sportster "project" boat. Meaning it had issues with cables. I replaced the throttle and shifter cables after a little bit of searching and some creative fabrication. Cables are good now. However, the boat cranks fine but won't start, or even "pop". I checked for spark. Has spark. New plugs. Fresh gas. Being new to Seadoo Jet boats I'm wondering if I'm missing something in the start-up process perhaps? Are there obvious things I should be checking or looking for? Any suggestions appreciated! Other footnotes. Previous owner installed new short block, new starter and bendex gear.

 

[brushmore]

If you have spark and compression, then fuel is where you should check next. You can try to put a little mixed gas directly into the cylinders to see if it fires. If so then you know it's the carbs.

 

[Sailorboy58]

If you have spark and compression, then fuel is where you should check next. You can try to put a little mixed gas directly into the cylinders to see if it fires. If so then you know it's the carbs.

I tried direct fuel injection. No "pop" or firing. Actually, I'm not 100% certain about the spark now. I'm getting a constant red oil light for 30 seconds after I attach the key plug. It could be the throttle position sensor in the cable isn't set up right and is putting it in safety mode or something. I'm going to readjust the throttle and oil pump cables and see if that helps.

 

[mikidymac]

Is this s fuel injected engine? Or carburetors?

 

[Sailorboy58]

Is this s fuel injected engine? Or carburetors?

The throttle bodies have choke plates so I'm assuming carburetors.

I've pulled the plugs and cranked several times to vent the gas from the engine. But when I try to start, plugs come out wet when I check. I'm going to do another spark test today now that the TPS is set up properly.

The oil light does go out now after I attach the key fob. It was staying on before indicating ignition override. I was also getting a "false low" reading on the oil tank sensor, which may have contributed to the flooding problem if it cuts out ignition.

 

[mikidymac]

Carb rebuild with only genuine mikuni parts and needles and seats.

The TPS is only for 80% throttle and above, it will not prevent it from starting.

Do you have spark? If yes then the carbs are flooding the engine.

 

[Sailorboy58]

Thanks for the wise words. That's where I think I'm going next. It won't hurt to give the carbs a genuine rebuild and cleaning regardless. Too much rain outside to do a spark test today but I'll keep you posted.

 

[Sailorboy58]

Thanks for the wise words. That's where I think I'm going next. It won't hurt to give the carbs a genuine rebuild and cleaning regardless. Too much rain outside to do a spark test today but I'll keep you posted.

Carb rebuild with only genuine mikuni parts and needles and seats.

The TPS is only for 80% throttle and above, it will not prevent it from starting.

Do you have spark? If yes then the carbs are flooding the engine.

 

[Sailorboy58]

So

Carb rebuild with only genuine mikuni parts and needles and seats.

The TPS is only for 80% throttle and above, it will not prevent it from starting.

Do you have spark? If yes then the carbs are flooding the engine.

 

[Sailorboy58]

Here's an update Miki.

I have what seems to be good spark. However, when I insert new plugs and crank it, they come out wet and "slightly" oily. I've disconnected the fuel lines and oil pump to give the crank a good cleaning before attempting a start up as it might be case-loaded. However, one point. When I first tried to start this after changing the cables, I hooked the hose up to the deck fitting and ran it lightly before I tried to start it. I've read now that water can back up into the motor. I'm wondering if that's the issue. In light of this, I've ordered a manual because it's almost time to winterize. Thanks again for your advice!

 

[mikidymac]

Never, ever have the water on with the engine off.

 

[Sailorboy58]

Yes. I found that one out a little late as it wasn't mentioned anywhere. Now the trick is going to be how to dry it out.... any suggestions? I disconnected the fuel lines and oil pump cable so as not to load it up further and have been cranking it with the plugs out and throttle wide open a few times a day.... ;-) It seems to be drying out somewhat but it's a slow process.

 

[mikidymac]

You have to run it to get the water out and the longer is sits the greater the chance of crankshaft damage. You have to run it, cranking will not do it.

 

[Sailorboy58]

Yes. I totally get that. But it's a little difficult to run it, if it won't start at all. Although the plugs are coming out much drying now after the cranking. Catch 22... I tried a little direct fuel into the cylinders but still not popping. If there's any water coming through at all, I think it will dilute the gas below firing concentration.