Outboards, impellers, pilot holes

edwardf · Posted: Thu Oct 04, 2007 7:50 pm Post subject: Outboards, impellers, pilot holes

My 2006 Suzuki DF90 gave me a scare yesterday. I started it up and as I always do I look back to see if the water stream is coming out of the pilot hole. It wasn't! The manual says you have 15 seconds before the world ends as you know it if no water is coming out. I was taking the boat out of the water at the time so when I got home I hooked up the earmuffs and the garden hose and started her up again. For about 10 seconds no wee wee. Then it began to spit, then wizz normally. This motor is barely a year old and has 30-40 hours on it. No overtemp alarms occured. Fresh water use only.

I have read the "Outboards and Systems" forum, "water pump impeller" on this site. Good stuff there but I'd still like to ask:

-Can something clog this pilot hole like it appears something did? (Forum responses say yes but...)
-Wouldn't there be enough pressure there to blow out a clog?
-Will the earmuffs and hose pressure give a false indication of a good impeller?
-Should I use a barrel/bucket/garbage can test instead?
-Could I be approaching impeller failure and the Suzi needs to go see a Urologist?

I was going to put her in the river over behind Newport (OR) but now I'm hinkey.

marvin4239 · Posted: Thu Oct 04, 2007 8:14 pm Post subject:

I don't know about Suzuki even though I have one but I use to have an 85 HP Johnson that the pee hole constantly got clogged by debrey. I would run stainless leader wire up the hole to free it up. If you didn't get a temperature alarm my bet is it was just a little trash in the pee hole.

Sea Wolf · Posted: Thu Oct 04, 2007 8:20 pm Post subject:

edwardf-

The "pee hole" on outboards is frequently plugged up from either debris circulating within the cooling system (really from the water source), or from insects that make it into a nest site for themselves. Insects also sometimnes lay their eggs in the cavity and then seal it up with mud. Similarly, a pupal stage insect often crawls in the space to quietly metamorphose into an adult.

I've had that same scare often, particulary with small kicker sized outboards.

Keep a small diameter flexible wire or plastic piece like a nylon string from a weed eater handy to poke around behind the hole and loosen up the blockage.

No, the pump pressure won't always blow out the debris, and you shouldn't use so much pressure with the ear muffs to assist it in doing so, either.

Your new motor should be fine, it's just another false gremlin invented by Mother Nature to scare you half way back to the outboard shop!

Good Luck!

Joe.

edwardf · Posted: Fri Oct 05, 2007 2:43 pm Post subject:

Thank you guys. A classic case of bug in the orifice but I still wonder if the pressure from a hose and earmuffs will give you a false indication that the impeller is OK. I know a guy who demonstrated a boat in his driveway, all looked good, but as soon as the new owner put it in the lake, it overheated - bad impeller.

Sea Wolf · Posted: Fri Oct 05, 2007 3:31 pm Post subject:

journey on · Posted: Fri Oct 05, 2007 3:52 pm Post subject:

Regarding using ear muffs (rabbit ears) to "blow" anything through the engine, note that the impeller is a positive displacement pump, and (up to a point) pressure on the motor inlet does not transfer to the outlet. Also the rabbit ears are flexible, and not much pressure exists at the motor input. When the engine starts, the water is sucked in, and the muff leakage goes down.

I still think that muffs are better for the use than bags. For one thing the intake water isn't contaminated with salt. For another, the mess when you put the engine in gear is less.

Boris

thataway · Posted: Fri Oct 05, 2007 6:11 pm Post subject:

Yes, muffs will give a false impression.

The hose will not blow out debris. The obstruction to the "pee" hole, may be further up the hose system.

The 10 second or so, relates to water at the impellor, if it is not greased etc--but if the muffs are on, or the lower foot is in the water, the impellor blades should be OK. The 2006 should still be fine--I change every 2 to 3 years. The Honda 130 on Frequent Sea didn't Pee--and had the origional 2003 impellor. I changed the impellor, it peed slightly better (also flushed the engine with Salt A way, and used compressed air to blow out all passages. On Lake Powell, it all of a sudden started "peeing"--and part way thru the Catalina trip, it decreased, and then increased. Not to worry, if the temp remains normal--the newer Suzuki's will interface with the NMEA 2000 guages and read water temp--not sure if the 2006 is compatable or not.