No Tell-tale stream at high throttle - Mariner 15HP

walke933 · #1 July 27th, 2004, 05:28 PM

I have a Mariner 15HP, 2 Stroke (not sure of the year) that doesn't give off a tell-tale stream when running at high throttle. At lower throttles, there is a good stream. At high throttle one of two things happens:

1. Stream slowly dies away and turns to steam.

or

2. Water hose that connects to pee hole comes off and fills engine case with water.

Almost seems like the pee hole becomes clogged somehow at high throttle.

Anybody have an idea why this is happening? We changed the impeller last summer, with very little use since then. And, like I mentioned, tell-tale stream is good at low throttle.

Thought about drilling a hole in the side of the case and sticking the water hose straight out the side - bypassing the pee-hole.

Thanks in advance for any help.

Jason

btatum · #2 July 28th, 2004, 07:51 PM

better drop the lower unit and ck the water pump impeller, very possible it has cracked or split to the point that at idle the suction created to bring the water into the pump housing is low therefore it will pump, at higher rpm's instead of pulling water into the pump it will cavitate and not pump water. as for the hose, i would just replace it and use small zip ties to secure it.

emckelvy · #3 July 28th, 2004, 10:53 PM

Also check the thermostat if so equipped. Sounds like something's salted up or plugged up.

The only reason for the hose to blow off the telltale is if there's debris in the plastic telltale fitting, causing a stoppage which builds up pressure. Try backflushing the telltale or blowing back with air, with the water hose disconnected from the telltale.

I've seen motors so full of silt, sand, & debris that the stuff was constantly breaking off the insides of the water jacket, then going out and plugging up the telltale. Had to remove the cyl block water jacket cover (the one over the spark plug holes) and clean it out.

Note: your Mariner, if it's a Yamaha motor, may have a cyl head and not a water jacket cover, the diff would be very apparent by the size of the bolts holding the head/cover on; head bolts would be quite a bit larger. Also the head's a lot thicker than a cover would be.

HTH........ed

phatmanmike · #4 July 29th, 2004, 08:51 AM

i had same thing with my 115 merc, turns out, i took 'er apart and she was FULL OF SAND wich was imeding the flow at higher rpms... just a thought

walke933 · #5 July 29th, 2004, 10:58 AM

Thanks very much for all the replies. Sounds like I have some work to do!

KCLOST · #6 July 29th, 2004, 12:33 PM

Let us know what you find...