should I be worried?

[Robmc]

Just dropped off the lower unit to replace the impeller yesterday and was greeted with this lovely sight.

Engine has been running fine all season and a reasonable telltale, although couple of times have had to use the paperclip up the outlet to unblock, but otherwise fine.

Given the missing rubber should I be worried about potential blockages or , if the engine's been running fine and the tell tale is fine, put a new impeller in and carry on?

Reckon I must have made a rookie mistake at the start of the season when I run my engine in a tank (rather than muffs) and, while the water covered the inlet, I think it needed to be deeper to provide enough pressure into the intake.

[Fenlander]

Oh that's a dilemma. Those rubber chips will be somewhere in the engine as they will be too large to exit the pee hole. What engine is it?

[Pikey Dave]

Originally Posted by Fenlander

Oh that's a dilemma. Those rubber chips will be somewhere in the engine as they will be too large to exit the pee hole. What engine is it?

Most of the debris will (hopefully) have gone out of the main exhaust, presumably through the hub. If the telltale is strong, there’s none in the telltale circuit. I’d remove the thermostat & get the hose pipe in & give it all a flushing
I’ve seen impellers in worse states tbh. I wouldn’t be too worried..

[Robmc]

Thanks - removing the thermostat and flushing straight up while the lower leg was off, was my thinking. It's a Tohatsu 60 - only 2nd season and around 40 hrs

[Fenlander]

>>Most of the debris will (hopefully) have gone out of the main exhaust

As you say, you would hope. I'm super thoughtful after that Johnson overheat and failure last year so was wondering which outboard it was and what the route of its passageways might be and what's involved with the tee off to the pee pipe..

[Peter_C]

All things considered they are pretty small chunks, but it would be worth it to see if they can be located.

[spartacus]

You might want to investigate further. My Tohatsu pees like a horse, and I’ve never had to unblock the tell tale, compared to my Mariner auxilliary that randomly gets strimmer nylon up it’s chuff if it’s spluttering on tickover.

If you remove the thermostat, you’ll need a new gasket. They are inexpensive.

Only fit genuine Tohatsu impellers. They are well made. Use a smear of marine grease on the vanes to lube on refitting. Any issues with overheating, then you could investigate the head. They do get furred up regardless of routine flushing. Try a salt away solution to see if that improves things.

[Peter_C]

Originally Posted by spartacus

~Use a smear of marine grease on the vanes to lube on refitting.

Yikes!

Maybe a "personal lubricant" or silicon, but even then why? Water is the lube. Grease and rubber tend to not get along very well, and could cause premature failure. At least with anything petroleum based. I sure wouldn't use grease on my impeller vanes, nor I have ever found the need to lube them.

The shaft on the other hand, needs to be greased against the inside of the impeller, so it is easier to remove in the future with less chance of corrosion, for which marine grease is preferred.

[Robmc]

Originally Posted by Peter_C

Yikes!

Maybe a "personal lubricant" or silicon, but even then why? Water is the lube. Grease and rubber tend to not get along very well, and could cause premature failure. At least with anything petroleum based. I sure wouldn't use grease on my impeller vanes, nor I have ever found the need to lube them.

The shaft on the other hand, needs to be greased against the inside of the impeller, so it is easier to remove in the future with less chance of corrosion, for which marine grease is preferred.

Thanks - agree no grease on the impeller vanes (have never done that in the past), but the metal cup that sits inside the pump housing and into which the impeller fits, does need a smear of grease - the one on this engine has been shagged (to be technical) by the impeller.

Have re-flushed with out the thermostat seems all good so I figure I won't worry about it unless the overheat alarm goes off!