Low rev issues

[Dpgw]

Sorry if this has been asked in a previous thread, or is a relatively simple fix, I’m a complete mechanical novice. I’ve recently bought a bf10 (?) 10hp fourstoke and have the following symptoms:

Starting issues: takes an extremely long time and a lot of effort to start, pulling the choke out seems to make it worse as it dies immediately unless the choke is instantly pushed back in, then has to be revved very high to keep from dying straight away

Accelerating: unless high revs are put on just before putting in gear, it will die as soon as load is put on, if it has idled (tickover)for any length of time it will die as soon as it’s put in gear

Low speed: will die in any low rev manoeuvre such as pulling along side a bank, where switching between forward and reverse is necessary. engine runs well as soon as you are cruising at consistent revs but at low speed (3knots estimate) the revs will lower themselves to tickover without any throttle input and then it will die

Water exhaust: dribble to slow drip of water out of the exhaust only, not sure if related to above issues or just a separate issue

Engine works great as soon as it gets going but obviously these issues make any usage quite stressful

Like I said I’m completely new to outboard maintenance and trouble shooting so would appreciate any pointers

Thanks

D

 

[Dpgw]

Forgot to say that it has been serviced just before we brought it, and the carb was cleaned new spark plug etc

 

[jgmo]

Hi Dpgw,

Do you know about what year the outboard was sold? If it's one of the old ones with breaker points and condenser, the contacts have to be adjusted periodically.

The old ones were called B models.
The later models were BF models.

i know you say yours is a.BF100 but I just want to be sure that's accurate because people get them mixed up.

I think that your engine might need a valve clearance adjustment based on the symptoms that you listed.

Also, check the timing belt to make sure it is not overly loose or damaged in some way. An engine that is slightly out of time could also behave this way. The timing belts on these are very tough and rarely fail but these outboards are getting pretty old and rubber deteriorates eventually.

Working on these is pretty basic and not particularly difficult but still, you will need a little bit of specific knowledge.

If you're going to work on it yourself you will probably need a shop manual to get things right. The real deal official Honda manual can be ordered here:

Honda Marine | Shop Manuals Publications | Honda Power Products Support Publications

publications.powerequipment.honda.com

The BF100 manual is the fifth one down after selecting the "portable" button and then "BF"

Good luck.