HELP Memorial Day is coming and my Sportser has no top end power?

[seeya]

Hello everyone. I was told this would be the place to come for advice. Forst off I hope that eveyone has a great holiday weekend and thanks in advance for any feedback!

I bought a 1997 Sporster two weeks ago that has a 1 year old rebuild on the motor. My problem is that the first weekend all was well (with the exception of feeling like it might need a wear ring replacement). This last weekend I took the boat out on our lake and it runs fine for a couple of minutes and then it starts loosing the high end power. What I mean is if I have it at 3/4 to full throttle I am cruising and then it slows down like I have pulled the throttle back. It still runs and idles, but wont pick up any power.

This is not a bogging down problem so I didn't think it would be carbs it just feels like I have the throttle in the low position regardless of where it is.

Any ideas?

 

[Dr Honda]

The RPM's are staying high, and the boat is slowing down?


When you give it full throttle from a stop... does it seem like you are "Spinning the tires" and it eventually gets traction?


If so... it's classic cavatation. Check the impeller, and the wear ring. (needs to be smaller than a 0.040" gap) but, I'm going to point my finger toward the carbon seal on the driveshaft.


If you are loosing RPM's... then it's time for a fuel system cleaning. (along with the carbs)

 

[seeya]

No it is just losing power as if I had pulled back on the throttle. Seems like it might stall if I left the throttle in a high position, but coast along fine at a low throttle position.

 

[seeya]

not sure why it only happens after it appears to have warmed up?

 

[Dr Honda]

Sounds like the carbs are plugged up. If it's going to stall if you leave the throttle up... it's starving for fuel.

Look into it before you burn out the engine. 2-strokes don't like to be run lean.

 

[seeya]

I will check it, but it seems like it would have a bogging down feel like my gti did and would do the same thing when first running around as apposed to just after a while?

 

[Dr Honda]

are you getting a good strong stream of water from your pee hole??

Does your beeper work all the time?

You could have a partly plugged cooling system, and it's over heating.

You can check your sender by putting it in hot water, and check it with a meter. Then you can check the beeper by turning on the power (turn on key, or put on the lanyard) then ground the wire going to the sender. When grounded, the beeper should sound.


I'm still leaning toward carbs/fuel system with what you are telling me. (unless you tell me your beeper is dead)

 

[seadooya]

need a wear ring. Think your overheat'n the bi***. Go thru carbs, install ring, then give'ur shot.

 

[seeya]

did the wear ring, but have the same problem. Replacing the heat sensor now with one off another motor to see if it is bad and causing it to think it is overheating. If that doesn't work I will do the carbs.

 

[seeya]

On another note, I picked up a super clean 94 SPI and Shuttlecraft today

 

[voodoo]

Same 2stroke ideas apply, make sure you have leak-goo-steel gas can trash free fuel system and you use the same oil as what the motor has already to prevent the gel of oil mixing from plugging things up, always get a bottle of oil from old owner.

 

[seeya]

I honestly never thought about changing the oils as being a problem ( I do premix) and I always use the 5 gallon plastic gas containers.. am I going to get banned now? lol