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I'm hoping that someone will know the cause of / solution to my problem.

My 99 Yamaha F50 idles fine upon starting (800 - 1000 rpm), and if I'm only cruising the harbor it's OK, but if I'm out in the Pacific running the engine awhile (above 4000 rpm), when I shift into neutral it continues to idle between 2500 - 3000 rpm. Cutting the engine and restarting doesn't help, and the clunk I hear when having to shift back into gear from such a high rpm doesn't give me good vibes at all. At first it seemed like an anomaly but seems to be a regular occurrence lately.

Any ideas?

Clipster - I just started having a similar problem with my F50. I just posted another topic hoping for help. Did you resolve your problem?

I presume you have carbs on that model year, I got 4 carbs on my 2000 BF. Could be a malfunctioning choke solenoid or some other device designed to up the throttle. Could also be stuck linkages that you may be able to eyeball. You need to be careful not to mess up carb sync unless you have a mercury gauge and know how to use it.

I assume you have a carbureted engine. This could be linkage or mixture related. For linkage: take the engine cover off and check to see if the carburetor butterflies and related linkage are against the idle adjustment stop. You can probably pivot the linkage by hand to verify this. If not you need to determine why the linkage is not dropping to low idle. For mixture: the engine may be idling toolean after it is warmed up. This can be an idle mixture set too lean (if you have that adjustment), a partially blocked idle mixure jet in the carbs, or an air leak that gets more significant as the engine heats up. When the engine is in this too fast idle mode, try adding a small amount of manual choke. It will slow the engine down but try to notice if the engine runs smooth or if it becomes immediately too rich. If the engine slows down and is still running very smooth you are probably too lean. Now you can figure out why (adjustment, blocked idle fuel flow, or air leak).

Thanks for the reply.

- The engine is carburated.
- The throttle linkage was adjusted so the lever was against the idle screw. I just had the carbs adjusted and sync'd about a month ago and it was running great until last week.
- Not sure how I would add manual choke to test if running too lean. My controls have no choke mechanism on them. They only have the control arm, a key slot, and a neutral throttle lever.
- I am thinking either I have
a) An air leak somewhere - I seem to recall getting a getting a bit of gas on my hands the last time I used the primer bulb. It may be sucking more air as it warms up. OR
b) A faulty choke solenoid.

My Honda used to do that with the old cables.......for whatever reason when I would take it out of gear, it would cause the idle lever to rise up and do just what you are describing. Once I changed my cables......it never happend again.