Ron, I have the Nissan 3.5, same as Mercury 3.5. When I run by OB in a tank or on the water there is a small valve on the left side that I turn to the "OFF" position while running the engine. I let the engine run until it dies from fuel starvation. That seems to work for me but I am no expert, just seemed like common sense IMHO. On the issue of extra fuel for longer voyages, there was a post several months ago on the Mboats blog and I think the sender hooked up some clear tubing, an inline squeez bulb and more tubing to a 3 or 6 gallon tank. This was for voyages to Catalina island! This blogger had a 3.5 or 4 hp OB. Find these instructions on MBoats for the details. Fair Winds....Larry Hughston M-15 Old 189 in Sacramento -----Original Message----- From: montgomery_boats-bounces@mailman.xmission.com [mailto:montgomery_boats-bounces@mailman.xmission.com] On Behalf Of Ronald McNeil Sent: Sunday, October 14, 2012 8:39 AM To: montgomery_boats@mailman.xmission.com; For and about Montgomery Sailboats Subject: Re: M_Boats: Yamaha 4hp or Mercury 3.5hp on M17 First I want to thank everyone for their feedback from when I originally posted this message in Sept. It’s been very helpful but I’m still not settled on my motor choice. I still really like the idea of going with the lighter Mercury 3.5 but I have a couple concerns. One concern I have is with adding fuel while on the water. For day outings it’s not an issue since I will typically never run out of gas with the .3 gallon internal tank, but when I go to the HPCC in February, I’m not sure how I will add gas. I don’t want to be caught hanging over the back of my boat with a gas can and I especially don’t want to spill gas in the water. I know a lot of you have similar motors with internal fuel tanks, so how do you deal with this? I also know that the best way to avoid gumming up the carb and fuel jets when the boat is going to sit for more than a couple days is to run it dry. With an external tank you can simply pull the fuel line off and let it run dry. Does anyone know if the Mercury 3.5 has any kind of fuel value to accomplish the same? ________________________________ From: Ronald McNeil <ronaldwmcneil@yahoo.com> To: "montgomery_boats@mailman.xmission.com" <montgomery_boats@mailman.xmission.com> Sent: Sunday, September 23, 2012 10:08 AM Subject: M_Boats: Yamaha 4hp or Mercury 3.5hp on M17 Hi, I have a new M17 on order and I’m now shopping for a motor. I was planning to go with the Yamaha 4hp, but if I go with the Mercury 3.5 it would only weigh 40lbs vs. 60lbs, which I like. My biggest concern I guess with either of these is their ability to motor into a strong head wind. Does any have experience motoring in stong wind with these or like size motors on an M17?