2006 Sportster gas problem while running?

[Krod_777]

hey, this is my first post on the forums and I'm happy to be a part of it.
Unfortunately, my 2006 Sportster 150 with the 155 hp 4-stroke is having a little difficulty running after getting started. The boat hasn't been used in a year (I know, sucks), but I changed the oil, filled it with fresh premium gas, changed the battery and made sure there werent any problems with the bilge system or cooling system.
The boat starts fine, but after about 30-60 seconds of running it seems as though there isn't enough gas going to the engine, because the engine starts shaking until it eventually shuts off within that minute of turning it on. I have it on a lift in water while running it in neutral, but I took it out to see what happened when i accelerated while in forward and the same thing happened almost instantly. I've had a Seadoo owner come look at it earlier today and he has no idea what is going on! if anybody has experienced similar problems and knows a possible explanation, any info would be much appreciated. Trying to get wakeboarding on the bay as soon as possible.
Thanks!
EDIT: I figured the problem might be with the gas pump, but I bypassed it and the engine would still die after putting gas directly to the fuel injector.

 

[Dennis]

Replace the spark plugs. (3) NGK DCPR8E

 

[steveawright]

i had a similar problem... i used Sea-foam. cleared up instantly

 

[devonte007]

I agree, try new plugs and see if any improvement. Not a bad idea to dump a bottle of fuel system cleaner in the tank as well.

 

[El Toro 33809]

My thought was plugs too.

 

[Krod_777]

I tried some seafoam but it didn't help, so today I'm changing the sparkplugs. I've never done this before so if there are directions somewhere online can somebody please direct me to them?

 

[devonte007]

Plugs are easy and if you download the service manual there are detailed step by step instructions (click 'manuals' at the top of this forum page). Basically, you unplug the coil pack from wiring harness, pull the coil pack up and out. Then replace the spark plug. I like to you a bit of anti-seize the the threads, and a little dielectric grease on the body of the plug before inserting the new ones. Just take your time and do one at a time, very simple job.

 

[Krod_777]

alright! put in the new plugs and boat is finally staying on, but i now encountered another issue. the engine seems like its hesitating while in forward, and the engine doesn't seem to be accelerating past half throttle. I looked underneath to see if anything was stuck and took out all the seaweed, and ran it again on the water and same thing happened. Thanks for at least getting it running! if anyone can help on my other issue, that would be great too!

 

[devonte007]

Glad to hear that the engine is running smoother with the new plugs. As for your new problem, we need some more detailed info:

1: you say it is not accelerating past half throttle - give us some more detailed information, what are the rpm's? Is the engine just reving out of control and the boat not accelerating?

If the boat engine revs to full, but it does not hop out of the water then you have cavitation and must service the propulsion system.
Hope this helps!

 

[devonte007]

Glad to hear that the engine is running smoother with the new plugs. As for your new problem, we need some more detailed info:

1: you say it is not accelerating past half throttle - give us some more detailed information, what are the rpm's? Is the engine just reving out of control and the boat not accelerating?

If the boat engine revs to full, but it does not hop out of the water then you have cavitation and must service the propulsion system.
Hope this helps!

 

[dothadoo]

Make sure that all the plugs are tightened down all the way. You may not be getting the compression you need. It is generally a good idea to change the plugs in these boats once a year, unless you use yours year round. If they sit for a couple months or so, they will need to be changed. What are the RPMs at full throttle? I believe you should be getting somewhere close to 8000 or so. Also make sure that you have the correct key. Like devonte said, you could have cavitation issues and need to replace the wear ring if that is the case. You should be able to look under the boat and do a visual inspection of the impeller and wear ring around it. If there are any nicks or gouges of any type in one or either the impeller or wear ring, you will have cavitation issues, but the boat will sound like it is spinning up really high and not getting out of the hole like it should. You should notice it if you went from idle straight to full throttle. It is about like spinning the tires on your car, bc it can''t get traction.