Dirt dauber and engines

[vettnman]

I've used an outboard motor for 18 years now and have never had a dirt dauber problem until today. Boat's going in the shop today for it's 100 and 500 hr service, so I decided to run the boat on my local lake to "test and tune". Right away noticed the port motor wasn't peeing. Shut her down and found the dirt dauber nest in the pee hose. Had to spend 30 minutes clearing the hose before I finally got a strong stream. Thought that was the end of it until I noticed that the same motor was bubbling a lot of air out of the prop. Have you ever seen a inboard diesel bubbling air out of the exhaust tubes? That's what my four stroke zuke was doing and it's not supposed to be doing that. No alarms, pee stream wasn"t any warmer than the starboard, I couldn't figure it out. Went ahead and finished my tests, and put her on the trailer. Got home and hooked the motors up to the muffs. Everything seemed to run fine with no discrepancies between the two motors so I started to just go over every surface of the port thinking that I might find a problem somewhere. Bingo!! I have no idea what would have stuffed grass into the exhaust below the cowling, but something had plugged that hole full of grass. I'm assuming that this would solve the bubbling issue, but what do you guys think? I'm definitly going to mention it to the shop when I drop her off tomorrow. BTW, both motors have zuke sunbrella covers, but I'm pretty sure both exits are exposed below the covers.

[peterbo3]

We get insects building nests in holes down here too. I cover the tell-tale & exhaust ports with a piece of masking tape when the critters are active. If you forget to remove it before launching, it will blow off as soon as the engine is started.

[offshore]

Nothing new Dave the best thing you can do is get motor covers that cover all the holes. I had carpenter bees in the Honda!! When I cranked that thing up The motor spit out 10 of those suckers. Dad used to get daubers in his motor till he finally bought a motor cover that covered all the holes. Check your fuel vent they like that as well. You can also put tape over the exposed openings...Mark

[vettnman]

Do you guys think that removing all that grass would eliminate the bubbling at the prop that it was doing? Tape will be a must do from now on.

[offshore]

Could have Dave. If you are not getting any alarms you should be ok. Could have been backing up a little extra exhaust through the prop hub. Remember 90% of your exhaust does exit from the center of the prop...Living in the country with all those critters will keep you on your toes!! Mark

[evilgli]

thats the first time i have seen that..interesting..glad you found it dave.

[welder]

DUH.............Masking Tape

Thanks Pete , I will be picking up a new roll tomorrow.

[vettnman]

Mark, I definitly live out in the boonies here. Deer constantly in my yard, dirt daubers all over the place as well as birds building nests everywhere, woodchucks gnawing on the trim at my front door, fox eating my table scraps, I could go on. Someone suggested that the grass may have come thru my water intake screen and worked it's way all the way thru my cooling system. Who knows??

[blueh20pc]

Originally Posted by vettnman

Someone suggested that the grass may have come thru my water intake screen and worked it's way all the way thru my cooling system. Who knows??

No way, between the impeller and housing and the small cooling passages of the head and the block, nothing that big is coming through there.

I wouldn't even change the impeller. I subjected mine to much worse treatment last summer when I towed a guy back for an hour with the flushing plug missing, hence, no water pressure for the impeller. I pulled it apart this spring, looked like it was new. Evilgli can verify, it would've gone another 300 hours before it even thought about failure.

That being said, my Zuke is now out of warranty, bet she throws a Rod next trip!

[blueh20pc]

Also, Tabitha doesn't look to be to happy to extract that piece of grass so you can document it for future reference. Stop polishing your cowlings!