Honda 40 Hard start, rough running

[donaergo]

My BF40A is very hard to start and runs rough most of the time. I have drained the carburator bowls, used fresh gas, and installed a filter/water separator. Is there anything I can do to adjust the carbs, idle, or anything else before I have to resort to taking it in to a mechanic? The engine has 114 hrs and problem seems toget worse.

Any thoughts?

Don

 

[Skinnywater]

Re: Honda 40 Hard start, rough running

There isn't any carburetor adjustments that will cure a failure. A water/filter separator and fresh gas after the fact do little in correcting a failure.

You don't say if your's is a remote controlled engine but if it is check to see if the choke selenoid is sticking.
You may want to pull the plugs to at least get a clue what cylinder is having difficulty and what that difficulty might be.

I recommend asking some of your fellow boaters who in the Seattle area has a good reputation in repairing your motor.

 

[donaergo]

Re: Honda 40 Hard start, rough running

There isn't any carburetor adjustments that will cure a failure. A water/filter separator and fresh gas after the fact do little in correcting a failure.

You don't say if your's is a remote controlled engine but if it is check to see if the choke selenoid is sticking.
You may want to pull the plugs to at least get a clue what cylinder is having difficulty and what that difficulty might be.

I recommend asking some of your fellow boaters who in the Seattle area has a good reputation in repairing your motor.

 

[donaergo]

Re: Honda 40 Hard start, rough running

It is a remote controlled outboard. What does the choke solonoid look like and where is it on the motor?

I checked all three plugs and they all looked good I then pulled the plug wire on #1 and #2 cylinders and did not notice any real difference. I checked that I was getting spark at each plug. Pulling #3 causes the motor to stall. Sounds like fuel problem to me.

Do I need to clean out the carbs to make sure that jets or floats are not at fault? I would check the choke solinoid as the first step.

 

[Skinnywater]

Re: Honda 40 Hard start, rough running

The selenoid is the electrical unit that is attached to your choke linkage. The plunger is prone to stick and a simple light application of oil on the plunger is a good practice.

Not trying to be a wise guy or anything and I'm actually doing you a favor in this next comment.
The work proceedure of those carbs are far to extensive for someone who isn't able to locate that selenoid on their own.

 

[OBMD]

Re: Honda 40 Hard start, rough running

Sounds like the carbs need to be cleaned. What year is your motor? You may not have a choke SOLENOID, but have an enrichment valve. If you do, have your Honda dealer call the tech-line and ask for Jeff. He is the lead marine tech. Honda has a few "new style" enrichment valves that improve the hard, cold start issue.

 

[Navigator]

Re: Honda 40 Hard start, rough running

Sounds like your Carbs may be out of sync. The 40's are notorious for running rough if the carbs are not "Exactly" in sync.
Symptoms of out of sync carbs are: Less power, bogging at
various rpms, and poor performance. What you'll get is a stumbling idle unless you give it a bit of gas. Back off too fast and you risk stalling the engine out. At high RPM, it will seem smooth although it will feel as if you've "lost" some power. I know this because my 40 was acting the same way at the 140 hour mark. If you own a carb sync guage and know what you're doing, it just a few simple adjustments to get them all equal. The Honda Carbs are great, but the operational tolerances are very tight.

Nav 8)