Impellor gone again

[Surfdad]

Ok I know I have some issue, I just replaced an engine from a bag cutting off the raw water intake. I've replaced the impellor, literally every two months, I just replaced the impellor housing and impellr with the new engine and 6 weeks later my impellor is gone. It has done this for the 5 years I've owned it.

It's a Black Scorpion engine, I do believe there is a shim kit installed that was supposed to eliminate this issue, is there anything else it could be? I mean I have replace the impellor no less than 15 times over the years and the housing at least 3 times. PLEASE don't tell me it's jinxed!

Thanks for any and all input.

[chpthril]

May be a stretch, but is it the wrong impeller? Have you been using the same part # from the beginning?

Has the V-drive cooler and trans cooler been opened up and inspected for a restriction or defect in machining of some kind?

Something really strange going on.

Can you post some pics of the toasted impeller?

[Surfdad]

I'm going to take it to the shop to have this one replaced, I've replaced some of them, the shop has done some, so after they replace this one, I'll post up pictures.

Because of the different folks (me and mechanics) I can't honestly say if it's been the same impellor.

I have never opened any of the coolers up, where and what should I be looking for/doing? Thanks Chpthril

[chpthril]

I have never opened any of the coolers up, where and what should I be looking for

Anything that would restrict flow causing the impeller to run dry and burn up.

[Surfdad]

The shop went through everything when they replace the motor, I wonder if it's possible that some "part" is defective and so looks normal but is restricting the flow and also was partly responsible for frying the old engine.

I'm not even sure what to look for, in that regard.

[LovinPowell]

I would turn it entirely over to the shop, tell them all that has been going on, ask them to make sure that it is fixed and then if it happens again, take it back to them and hold them to it.

Good luck with it, I hate hearing that these things happen to good people.

That's my

[Surfdad]

Thanks LP and good advice!

[Fast1911]

My advice would have been the impeller housing, already did that and it fixed my problem, I guess I'm with LP on this one too.

[mtnsmith]

You could also install a seastrainer. If your water has much suspended sediment or vegetation that makes it into the impeller a seastrainer might help. I have 292 hours and have only replaced my impeller once, at 200 hours, and it was perfect when I took it out. We do have different engine makes, but still seems crazy to replace it that much.

[Surfdad]

I know mtsmith,

There has to be something beyond the impellor, housing and the alingnment shim...like chpthril is suggesting. The last few times it has fried it's been at the dock as we launch. We always make sure that the boat is in the water before firing it up. I've never run it dry, I have only used the fake-a-lake like three times during the last five years, just because of this. So...I'm thinking there has got to be something somewhere else that is the root of this issue.

[formandfunction]

If it makes you feel better surfdad my boat eats serpentine belts on a regular basis,no impellers though.

[FIC]

On some of the pumps you can mount them upside down putting the suction hose at the top which will sometimes cause pump cavitation and make it eat up impellars, check for proper pump mounting and that all hoses on the suction side have no drupes which can act like a sink trap and cause pump suction loss and impellar failure. Also check thermstat housing for impellar debre on pressure side backing up pump pressure. Hope you solve your problem.

[Surfdad]

formandfunction, thanks and I feel your pain!

FIC, do you have a picture or is there a way to identify the correct orientation of the housing? I'm going to take the boat into the shop and have them do all of this, I'm wondering if the housing has an arrow that points up or some-such-thing?

[FIC]

I dont have a picture and there are no indicators on the pump, just follow the through hull hose all the way to the pump housing and it should normally be hooked to the lowest fitting on the pump to allow trapped air to escape through the pump to keep it primed. We were getting a lot of 2002 to 2004 nautiques in for impellar failures and overheating and we found the pumps were in upside down and created a trapped air in the hose so the pump wouldnt prime, allso make sure when you follow the hose that it is a smooth flow all the way to the pump with no drupes , I have had that trap air if the hose drupes to much. Im not saying its your problem but it is worth looking at.

[kko]

also make sure to check the inlet side of tranny cooler to make sure it is not clogged. the sea strainer is a good idea.