General Loss of Power

[Chris024]

Hi Everyone,

New to the site but I've been lurking for a while lol. Just picked up a '91 Squarenose 650 a few weeks ago and just recently had a strange issue happen and haven't found anything online that helps.

Previously it's been running very strong (3-4 tanks through), almost jumping out of the water if i punch it from low speeds. Yesterday I took it out, it started up fine, idles fine and smooth, runs smooth, except that it feels like it's running at maybe 75% power. Where it used to punch hard on the low end, it now kind of has to "push" it's way outta the hole to get on plane, and the top end feels not nearly the top speed it was.

Felt like maybe the throttle cable slipped but that was fine. It doesn't sound like any misfiring (is that something easy to tell?). Gas is fresh and mixed (about 45:1). Could it be the ethanol in the gas just building up?

Strangest thing is the difference in power when the only thing it's done is sat on the trailer.

Any experience with this or places to start looking?

Thanks!

 

[long beach local]

Possible fuel filter blockage ? There is a small little screen on carburetor take the carb off and clean it or do a rebuild while your in there. Check the plugs they look the same put new ones in. Compression check , check spark etc I would start with simple stuff.

 

[headshock]

Hows your Impeller look?

 

[Chris024]

Thanks for the starter list, I'm pretty new to the small engine scene but that seems all doable.

Impeller looks ok, no chips, seems pretty tight to the wear ring. anything specific to look for on that?

 

[keith t]

Thanks for the starter list, I'm pretty new to the small engine scene but that seems all doable.

Impeller looks ok, no chips, seems pretty tight to the wear ring. anything specific to look for on that?

0.6 mm clearence absolute max prop to wear ring