Did I fry my impeller?

[Triple_D]

So I decided to change my oil today, I hooked up the ear muffs and turned on the water and ran my boat to warm the oil first but I didn't have the muffs quite over the intake enough apparently as I noticed some slight white smoke coming from the motor and there was no pee stream. UGH.

I had the motor running maybe 30 seconds before I saw the smoke and shut it off. The overheat alarm did not come on. I moved the muffs and restarted the boat figuring I couldn't do any more damage and I got a good water stream from pee hole both in neutral and in gear. I will pull the lower unit when I get a chance to check the impeller but I was wondering on the odds of it being damaged or not? There had to be some water that made it up there as the muffs were almost entirely over the intake screens initially. 2000 Honda 90 4 stroke.

Thanks

[CAMAN]

If you smelt smoke then yes you probably did start melting it. I wouldn't risk taking it out before atleast inspecting it.

[harvey lee]

It may be ok but for the cost of a motor, very easy to check or simply replace the impeller.

I have in the past pulled my lower unit to check the impeller but for the small cost of a impeller and since you already have it out, I would put a new one in.

[Moose-Hunter]

If you suspect the impeller is damaged... It's the "not knowing" that's gonna drive you nutz.

Pull the lower unit. If the impeller is bad, replace and get a good nights sleep. If it's good, replace it anyway. You win either way!

[Ufatz]

If you were seeing a good strong flow from the "pee hole" and there was not more smoke and no alarm I would say you did no harm. If impeller fried you would not see any stream since impeller would not be producing it.

Right?

[Surface Tension]

One thing is for sure, you didn't do it any favors.

Can't say for sure how much damage you did but if you have a good tell tale stream then it is pumping water although being hooked up to the hose, the water pump is getting help. If there was a little water spitting out or water coming the props hub your fine.

[marine_man]

If impeller fried you would not see any stream since impeller would not be producing it.

Right?

To Frank's point above... gauging your telltale indicator stream while running on the hose doesn't show much... the water pressure from the hose can in some instance be enough to provide a good stream.

marine_man

[311Hemi]

Any idea if what RPM it was at when you did this? Eihter way I think I would definitely pull the lower unit and check it. This pic is from a Yamaha manual I have:

[Ufatz]

Excellent point Marine Man and I should have thought of it!! While I would not panic over this I WOULD probably put new impeller in at first reasonable opportunity.

[Triple_D]

I was at about 1/3 throttle for 15 seconds and then backed down to idle before I moved to the motor and saw the smoke.

I decided to take the advice and be better safe than sorry and just change it anyway. I am picking one up tomorrow, tonight I pulled the lower unit and pulled open the water pump. There were a couple of small rubber chunks in the housing and the top of the stainless steel housing had some black streaks, otherwise it looked fairly good, is that streaking on the housing normal or was it from my "incident"?

Two other questions. I drained the lower unit lube before I took it off, did I need to do that?

My other question is do I need to change the black rubber O ring type gasket and the cardboard type gaskets underneath the steel plate that the water pump housing attaches to or will I be OK just throwing the new impeller in after cleaning up the housing? The kit comes with the gaskets and impeller.

[SpecialK]

More than likely the rubber chunks and black streaks happened during this incident. Do you need to change the gaskets and o-ring? Maybe, maybe not but you have it all apart anyway so I would change them out and be safe.

[boatfixer]

Depending on how bad the streaks are, you may be able to clean it up, but you will have to clean it completely. Any rubber left behind will shorten the life of the impelled.

My suggestion would be to get a kit with a new housing liner, gaskets, impelled, etc.

Do it right and you won't regret spending a few more bucks!

[SpecialK]

Depending on how bad the streaks are, you may be able to clean it up, but you will have to clean it completely. Any rubber left behind will shorten the life of the impelled.

My suggestion would be to get a kit with a new housing liner, gaskets, impelled, etc.

Do it right and you won't regret spending a few more bucks!

+1

[311Hemi]

You did not need to drain the lower unit.

When was the last time it was rebuilt? I would change them if I were doing it. If it has not been done in a long time I would just replace all the main parts which I would assume would come in the rebuild kit. That's just me.

[Triple_D]

The last time the impeller and gaskets were changed was 3 years ago. I suppose for the extra $20 or whatever it's worth it to buy the upgraded kit with the new housing, good peace of mind.

A guy I talked to said to spray the new gaskets with Permatex (I think that's what he called it) before installing. I have never heard of that, I'm kind of a novice mechanic. Is this necessary and where can I buy it, would NAPA or O'Reilly's have it?

Thanks guys.

[Northlander]

I would also get a whole new kit and toss it in. Easy, cheap piece of mind.