Rough idle on BF75D

I have a new BF75D that I purchased last July 2012 (manufactured in 2008 according to technical bulletins). It runs OK, except for the rough sound when you shift into gear on idle, but I have gotten used to that. There is one problem I can't seem to understand ,when I kill the engine and tilt it out of the water to use the trolling motor. I fish for about an hour or so and put the engine back in the water, start the engine, and it idles rough. When I put it in gear at idle, it shakes and misses like crazy. I give it a bit of throttle and it goes away and runs smooth. I don't think it should have a rough idle since it is "new". I have taken it back to the dealer and he and the Honda rep says my fuel was old and stale. OK, I put new fuel in it and it does the same thing. They said they tried a new circuit board and it read like the original. So, I guess I am to assume that all new Hondas run poorly in idle. I have seen other brands of engines and they don't do what this Honda does. They run smooth at idle, in or out of gear. I am pretty put out by the performance of this motor, as Honda has always had top notch products. Does anyone out there have any knowledge of this sort of issue with the BF75D's? Thank you for your reply.

Well I can't say it doesn't exist anywhere else. I suspect that their is liquid gasoline in the intake manifold that is causing you some grief. There are a couple area's of concern. A leaking fuel injector allowing fuel into the manifold causing an over rich condition, then causing the oxygen sensor to react to that. Then I suspect you are triming your unit up as high as it will go. If the vapor seperator venting solenoid or any part of that system is not working properly then fuel could bypass the solenoid and enter the manifold. It would be easy to figure some of it out for your self. When you stop to fish don't trim up as high or at all and then see how the motor react's. As for the quaiity of the unit, it is outstanding. I have commerical crawfishermen and oil field construction companie's trying to destroy them on a daily basis. I have one unit down at Delcambre Louisiana that has over 400 overheat's of course I have changed the head gasket a couple of time's. I keep telling those guy's to buy a Pro Drive or something else to get to their location because their is little to NO water. They tell me they will once they finally kill the Honda, however it won't be today. Thank's Martin

Did the Honda Rep say that this is normal? You should stick with the dealer until they get it fixed. If not satisfied, call the Honda Customer Relations (770-497-6600...8:30 - 5:00 m - f) and discuss with them. They will call the dealer and/or the Honda Rep and help them escalate the issue if necessary.

Mike

I had talked to the Honda rep and he said all sorts of things to lay off the problem to something else. From bad gas to "searching for" something. mcyama has nailed the problem, I think. It seems to make sense that fuel will leak into the intakes when tilted for travel, but not when the engine remains vertical. The O-rings were dry for up to 4 years, and at least one of them cracked. I will be addressing the issue the next time I can get up to the dealer. He is 65 miles away, but I will get it fixed. mcyama, thank you very much for your reply. I do think you hit it on the head. Thank you, Martin.