Honda BF50 Idle Problem

[TSWEST]

I have a 1997 Honda BF50 with a bad idle problem. The engine starts flawlessly but idles high. I've adjusted the idle screw but that's not the problem. When I manually move the throttle linkages, the idle settles to normal. It also idles perfectly in gear (forward and reverse). So the high idle sitting at the dock is more of an annoyance. However, here's the problem. When iding into the marina, I back into my slip, and the engine idles fine. As soon as I take it out of reverse, the idle revs high and it's virtually uncontrollable. It's something about coming out of reverse.

The throttle linkages on the engine seem overly complicated. Does anyone have any knowledge of these parts, and any difference in forward and reverse on these engines? I'm wondering if something is getting stuck (I've tried lubing everything I can find). I'm also wondering if it's a problem with the diaphragm or a vacuum problem. Again, if anyone has technical info on these controls, I'd appreciate it.

[silverfox441]

Check for a broken/bad PCV valve.It will cause the idle to be erratic on the high side. But it's only one possible problem out of a lot of possibilities. Always Go from the easiest to the more complicated when you troubleshoot. Do not put an aftermarket PCV valve on a Honda. Only OEM. Anyway, check that first.

[Tomfoolery]

Your carbs may need synch'ing. It only takes one, open more than the others, to bring the idle up with no load.

Also, there are adjustments for synchronizing the remote for throttle and shift functions. I have the setup manual for that engine, which includes remote control adjustments.

I had a similar problem, which included the neutral throttle lever coming up with main lever movement, and I was able to adjust it out. I also replaced the two cables (MUCH smoother operation now), and since I did it shortly after I got the boat some years ago, I just don't recall what was going on and why. But I do remember the neutral throttle lever was causing it, and it moving with the main lever (when it shouldn't) would happen more in one direction than the other.

If you PM me your email, I'll send it to you (2 MB pdf file).

[C Buchs]

Like Tom, I was thinking that it might have something to do with your shifter also.

Tom: I'd like that file also. I'll PM you.

Jeff

[Tomfoolery]

Happy to send it. The email contact info in the user profiles has no facility for attachments, so anyone who wants it needs to send me their direct email address via PM or email contact.

[TSWEST]

Thanks everyone for the information, very helpful. Any info on carb syncing would also be appreciated, even links to procedures or shot manuals. I have the Service Information book but it only shows illustrations, it's only marginally helpful. I use alldatadiy.com for auto service info - wish I could find something similar for boat motors. I've heard about Clymer - I may try that.

[Starscream]

I had a very similar problem with my bf50. It would idle so high that I would wince when I clunked it into gear. The dealer fixed that problem in about 30 seconds by playing with the throttle linkages. The problem came back once in a while but I was able to adjust the linkage myself after watching the dealer do it. I don't remember how to do it now but that's where I would start if I were you. That whole assembly did seem overly complicated and a bit wimbly (that's an engineering term for not so rigid or strong). Once you figure out how it works the adjustment is simple.

Now my memory might be totally wrong on this but I seem to recall that one of the joints in the assembly was a ball and socket type and could be easily popped out for adjustment. I think I remember doing that, and I can't think of any other reason to pop out that joint other than to adjust something. As I write this I realize that I might be leading you down the wrong path with my faded memories so please be careful.

[Tomfoolery]

Thanks everyone for the information, very helpful. Any info on carb syncing would also be appreciated, even links to procedures or shot manuals. I have the Service Information book but it only shows illustrations, it's only marginally helpful. I use alldatadiy.com for auto service info - wish I could find something similar for boat motors. I've heard about Clymer - I may try that.

Try motorcycle resources. Synching carbs is SOP, or at least it was 30+ years ago, when I stopped riding (got married, stopped flying small planes, and so on ).

[Phil M]

Syncing my BF50A was marginally useful, and slightly improved idling. Other factors were more dominant, but my isue was rough idling. After buying the sync kit (some motorcycles apparently need syncing) and researching YouTube the end results were hardly worth it in my case.

[mac n cheese]

The OP may find the following link useful if you want to check for correct rigging of the controls and remote.

http://boatinfo.no/lib/library.html#

Clic Honda and scroll to the right where you will find "BF50 Installation Manual"