2007 Honda BF200 engine shake

I have twin 2007 BF200's (serial #BAEJ-1500094 & 15) with only 200 hours. At any cruise speed, my engines are not stable. they oscillates back and forth as one might expect at idle. Linkage is tight. Bought the boat used. Not an experience boater for sure. Been on other boats and those engines seem way more steady if not still. Boat has squirrely handling on plane. Has a mind of its own. Boat is a 1995 Proline 2950 Walk.

All suggesting considered and appreciated

Marino

It could be the HO2 sensor. Those motors have the original style exhaust tubes per Honda Service Bulletin # 56, unless the previous owner had them changed out. The old-style exhaust tubes under certain circumstances allowed water to get too high up into the exhaust tubes and blow the HO2 sensor. Send me an e-mail and I will send you a copy of that SB. [email protected].

Suggest that you do too things:

1. Pull codes and see if you are getting an HO2 sensor fault, or any other fault. If you are not sure how to do that, send an e-mail to me, I will send back the procedure for pulling the fault codes and a paper showing what the codes mean.

2. Pull your plugs and see if you are getting a "good" burn on all of them. They should be milk chocolate brown. Pay special attention to #3 and #6 - the two lowest cylinders. If the plugs have black soot, then you likely have a bad HO2 sensor. If one or more of those plugs are sparkling clean, then you've gotten water into the cylinder. While you are at it, replace the plugs. Use NGK IZFR6F11 only.

I believe it is the port side plug that really needs to have the lower cowling removed to access. I know that before I started doing my own work on my BF200, my "mechanic" never changed that plug. It is not a big deal to do, just a little more time.

Also, it is possible you have a fuel delivery issue. Chawk has lots of info on the fuel system and all of the associated filters.

m smith said:

I believe it is the port side plug that really needs to have the lower cowling removed to access. I know that before I started doing my own work on my BF200, my "mechanic" never changed that plug. It is not a big deal to do, just a little more time.

Also, it is possible you have a fuel delivery issue. Chawk has lots of info on the fuel system and all of the associated filters.

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I ordered a new engine cover seal and realized that if I cut the lip that the cover seal rides on that I could change the plug and coil. I cut a couple inches off that lip and put the new gasket on and since it hadn't been crushed it still seals that area. If you could use a new engine seal gasket it is a nice mod to cut work out of spark plug checks and changes.

gasket #4 http://www.boats.net/parts/search/Honda/Outboard Engine/2002/BF225A2 XA/ENGINE COVER/parts.html

cut a section off of the uppermost lip off of cowling #20 just big enough to get the coil off of the plug without removing the cowling. http://www.boats.net/parts/search/Honda/Outboard Engine/2002/BF225A2 XA/EXTENSION CASE/parts.html

Thanks for the tip Nasty_Wendy. Could you post a photo or some dimensions to go by. Just so happen to have 2 new seals that I haven't installed yet. Fairly expensive mistake with a wrong cut.

Thanks all for the suggestions but I'm thinking that at least for the short term term the engines are OK. They pull 5800. Are there some rubber motor mounts that could be going bad (they are 10 years old). They oscillate (shimmy) from right to left like a bad front end alignment that has loose parts. Speaking of which, they are set at zero toe. Could this movement a sign of needing something other than zero?

Never had any issues with the motor mounts on my 07 that's just a bit newer than yours. Once warmed up, the engine should be pretty stable at any rpm's above idle, regardless of the condition of the rubber mounts, so I suspect you may have an operating problem of some sort.

When you say that your engines are "not stable" just what do you mean by that? Are they surging back and forth between, say 100 to 200 rpm's, or are they vibrating like a missing spark plug or coil?

Let us know whether or not you are getting any fault codes.

Also, please give more detail on your statement: "Boat has squirrely handling on plane. Has a mind of its own." "Squirrelly" is not a very precise description unless you're from North Georgia.

marinoperna said:

Thanks for the tip Nasty_Wendy. Could you post a photo or some dimensions to go by. Just so happen to have 2 new seals that I haven't installed yet. Fairly expensive mistake with a wrong cut.

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