bogging black max

[dawells]

I Have A 1986 V175 Black Max, Started Up And Ran Fine On Hose But When Got To River Would Not Get On Plane From Bogging. Had A Yamaha Did The Same Thing And It Was Carbs So I Rebuilt Carbs Did Not Help. Checked Fuel Delivery, Fuel Pump , Good Spark On All Cylinders And Compression Test Turned Out Good. I Am At A Loss On This Would Somebody Help

 

[hkeiner]

Re: bogging black max

Well, you covered the basics. If you got good spark, good fuel, and good compression and did all the testing and maintenance things you described correctly, the motor should run fine. Perhaps you did not do all the tests/maintenance tasks correctly or completely. Your descriptions of what you did are very general.

If you more fully describe what you did and how you did it, perhaps a mistake or missed step in what you did will become apparant. For example, cleaning the carbs with carb spray does not always get gummed up carbs clean enough. You need to use a gallon can of carb/parts cleaner and blow out all the passages with air to get them properly clean. Also, you can use a vacuum gauge or connect a portable tank to the motor to test for fuel restrictions in the fuel line upsteam of the fuel pump. There are many other tests that can be done to systematically troubleshoot the problem.

 

[lizardfish]

Re: bogging black max

if u did not soak your carbs for a few hours or overnite i would do so,and blow them out with compressed air,then u can mark that off your list of trouble spots..

 

[CharlieB]

Re: bogging black max

If the spark and compression are both good, then it has to be in the fuel system.

While it bogged did you try squeezing the primer bulb, that would show you if the fuel pump was failing to provide enough fuel to the carbs.

Also try 'bumping' the choke button, this would show you a lack of fuel in the idle circuit, either still dirty carbs or too lean of an idle mixture adjustment.

Adjusting carbs takes practice, it is very easy on the hose to set the idle too lean as there is no backpressure as when the motor is in the water.

Idle should be set in the water, in gear, to best idle speed PLUS 1/8 turn out to provide additional fuel to prevent that lean bog on throttle opening.

 

[billnsherisboat]

Re: bogging black max

I have a 150 v6 merc had the same problem and checked all the same things you did have someone check your stator voltage mine was putting out half as much as it should and did the same thing after i spent money on carbs plugs and all that