'05 Sportster 4-TEC - 5500 RMP = 20mpr top end - plugs or blocked impleller?

[justme]

Dealer winterized - normal 1st in water routine, fill with premium gas, add STP Injector cleaner as I have done for past 5 years. Launch boat - wife drives to dock, said was running rough while I was putting trailer away. Next day, attempt to go out but engine was running real rough (battery was run down) so I limped back to dock. Test battery (4-years old) replace with fresh new one.

New battery - hard to start, real hard. Not smoking, just cranking. Manually hold throttle open and she starts and sounds like normal. Take for spin on lake - no top end which is usually 40-45mph +.

Thought possibly water in gas would be cause after visiting this forum so I added bottle of heat to the mix and still the same performance which is 5500rmp = 20mph.

Enough background - its 6:50 in the morning, I am thinking I have fouled plugs and was going to take the hour ride to SeaDoo dealer and purchase new plugs.

Thought was once I get back to the boat - pull plugs and see if they are oily or not however new plugs are always a good investment IMO.

If new plugs don't do the trick, then I am thinking blocked impeller, wear ring or worse of all - dinged up impeller.

Any thoughts are most welcome.

Morning2ya'll

 

[justme]

Update - 100% back to normal.

$12.00 new set of plugs- simple to install and 100% back to normal. Based on reading posts - I was imaging worst case however - also reading the moderator comments, its a cheap and good investment for new plugs.

For those that are on fence -

After removing dipstick, simply unsnap the silver cover. Lightly grasph the black plug covers and slide them off (only one way)

The black plug connectors turn counter clock wise and come up and out via gentle pull and turn action.

The spark plug is exposed - slide long neck socket into slot and again counter clockwise and the plug pulls straight up and out.

NOTE: if you see some of the marine sealant around the area its worth the 2 minutes to shop vac before you pull the plugs.

Simpley reverse process and your done.

Apologies for putting these steps there - however, I am a computer guy and feeling really happy I just saved a dealer trip over the holiday weekend. Now if I just can get my brother-in-law to bring his own beer.

 

[devonte007]

I should also add that the manual says to apply anti-seize lubricant (silver grease) to the threads of each of the plug before you reinsert them, and dab a bit of dielectric grease on the spark plug boots where they touch the plugs. Both of these can be found at any auto parts store. Might be overkill, but in a moist marine environment last thing you want is the plugs to get seized in the head or a damaged rubber spark plug boot.

As a rule of thumb I always replace the spark plugs at the beginning of the year, after I run the fogging oil out of the engine. Simple and cheap assurance engine will run good.

Glad you are back up and running!