550sx suddenly wont start with loud noise

[Carl Nelson]

My 550sx has been running flawlessly all season. Earlier today, I noticed that it was making a strange sound (almost like a grinding noise?) at about 3/4 throttle and it wouldn't go any faster. At lower speeds, it seemed to run fine. Then later today, I checked all the wires/tubes to make sure nothing was loose and went to re-start it. The engine wont start and it makes this really loud metallic noise. It makes this noise whether the key is in or not. Any ideas? Did the engine somehow seize? With only a few weeks left to ride, I'd really appreciate any thoughts! Thanks in advance!

 

[MarkWalker]

Compression test? Something wedged in the pump?

 

[wmazz]

I am assuming your engine is squealing not clanking.

Visually inspect the pump. Remove the spark plugs,
and inspect them. Rotate the engine by hand and
try to identify what doesn't feel right.

It should roll over smooth!

Key spots to pay attention to is: pump, flywheel,
starter, and crank.

Sources for a "really loud metallic noise" are the
impeller grinding against the s/s wear liner and a
seized ball bearing.


Bill M.

 

[Carl Nelson]

I am assuming your engine is squealing not clanking.

Visually inspect the pump. Remove the spark plugs,
and inspect them. Rotate the engine by hand and
try to identify what doesn't feel right.

It should roll over smooth!

Key spots to pay attention to is: pump, flywheel,
starter, and crank.

Sources for a "really loud metallic noise" are the
impeller grinding against the s/s wear liner and a
seized ball bearing.


Bill M.

 

[Carl Nelson]

You were absolutely right, I took off the intake grate and the impeller is rubbing against the wear liner. I took the pump apart and the bushing is not seated flush. See photo attached. Bearings on drive shaft and in the pump rotate fine. It also seems like the wear liner is too tight for the prop. Do they typically swell or move over time? If so, do I just need a new one as well? Thanks for the help!