mouse nest in the lower unit

[oldboat1]

Here is one I hadn't run into before. I have a 10hp Chrysler Sailor (mod 100HA, '76-'77) and I've been fretting over the fuel pump and carburetor. I rebuilt the pump, and then went back in to make sure the fuel pump reeds were not bent out of shape. I cleaned the carb three times (maybe twice too many?) The motor starts, but won't keep running -- and runs at all only with pretty much full choke. It won't operate above an idle (doesn't necessarily quit with the throttle advance, but just doesn't respond) -- and the situation gets worse rather than better after the motor has heated up.<br /><br />Last night, I noticed that the water stream suddenly all but stopped, and the motor was getting too hot. In addition, there was a lot of exhaust smoke coming from the leg, and under the block -- whereever it could get out. I pulled the leg off, and found the exhaust completely jammed with what appears to be materials from a mouse nest (sorry if you just had lunch). In addition, the stuff was wound around the shaft. I've cleaned it all out, put in a new impeller and wear plate since I was in there anyway, and put it back together. It was too late to try it.<br /><br />So here's the question: Would back pressure caused by a blocked exhaust give me the problems? I know the leg is (was) pretty much full of water after testing, because it would slowly drain into a pail I put under it (about a gallon). I'm thinking it's a similar effect to the old potato-in-the-exhaust gag. I'm hoping when I get home tonight, I'll be able to fire it up and expect it to run like new. What are the chances??

 

[Chinewalker]

Re: mouse nest in the lower unit

Hi,<br /> I'd say your chances are quite good. Short story...<br /><br /> About a year ago I bought a junker/clunker 1980 4hp Johnson in a garage sale. I put some new parts into it, put the motor together and tried to start it. It popped, sneezed, and basically did everything but run. I set it aside, came back to it later, rebuilt the carb, replaced the mag, gave up and set it aside and repeated that pattern about three times over the last year. Well, this spring I started tinkering with it again, bound and determined not to give up this time and I was prepared to tear it down, figuring maybe a crankcase seal was bad and it wasn't drawing enough fuel or something. <br /><br /> These 4hp OMCs have an exhaust tuner under the powerhead and when I removed the tuner I noticed that the gasket under it didn't have a hole cut out. I could see my pencil mark where I had marked it to cut out, but apparently I never did. After slapping my forehead, I cut out the gasket, reassembled the motor, and that bugger started and ran on the first pull. I can't believe how many colorful words I wasted on the little motor in the last year....<br /><br />- Scott

 

[oldboat1]

Re: mouse nest in the lower unit

yup. Thanks for the post, Chinewalker. I'm hoping for the best. It just didn't occur to me.....<br /><br /> Curt