Black Max 200HP 1996 problems on idle

[edu01jose]

I'm having problems with my blackmax when on neutral it quits on me and shuts down. RPM's sound low and my tach is broken so the RPM's should be the problem.

Where is the idle screw on these motors? I haven't checked yet but once I go next weekend to the boat I want to try and up the RPM's.

Anyone have any information or any manuals?
Thanks!

 

[CharlieB]

Re: Black Max 200HP 1996 problems on idle

Is this motor new to you or is this a change in the way the motor has performed?

Troubleshooting any problem is best done starting with a few simple tests to ensure the motor is mechanically and electrically sound.

Compression test all cyls to ensure they are all making compression within 10% of each other.

Spark test each cyl to ensure the ignition is capable of firing each plug across at least a 7/16 gap with a hot blue arc. Any non-firing cyls can cause a rough idle and poor performance.

Once compression and spark are confirmed then you can proceed to the carbs, verify fuel pump flow, clean carbs, then adjust linkage and timing as spelled out in the service manual.

 

[edu01jose]

Re: Black Max 200HP 1996 problems on idle

The motor was new to me this summer.

I've had a mechanic inspect it and do a tune up.
What I believe is he did the tune up and adjusted the carbs but he adjusted them possibly on muffs. I think they would need adjusting on the water. When you put it on neutral it stays for a couple seconds sometimes and the motor is very quiet and you can barely hear it.

I want to try the spark test. How is this done?

 

[CharlieB]

Re: Black Max 200HP 1996 problems on idle

An adjustable gap spark tester can be found or ordered thru many auto parts stores, or you can build a simple one. Somewhere in these forum you will find a DIY Spark tester made from a piece of 2 X 4, nails and some wire.

To save wear and tear on the battery and starter, remove all spark plugs, reinstall the spark plugs into the wires and tape all the spark plugs together and attache a wire to the spark plug bodies threaded area, connect this wire to a good ground. This will give the electricity from the ignition a path to ground as leaving them disconnected can cause damage to the ignition.

Disconnect one wire and connect it to a spark tester, You want to make a gap of 7/16 inch, wire one side to ground, wire the other side to each plug wire one at a time. Crank the motor breifly and watch for a hot blue spark. Replace that wire to the spark plug bundle and move on to the next spark plug wire and test again, repeat until all cyls are tested.

Once all cyls are proven to have good spark you can move on to the fuel system and adjustments. If any cyl fails the spark test, download the free Ignition Troubleshooting Guide from the Support page of CDIElectronics their excellent guide will spell out the tests necessary to determine the cause of any spark failure.

Check these links to see if a service manual is available for your motor.

http://1manual.com/Mercury manuals/Service_Manual_Index.html

http://forums.iboats.com/showthread.php?t=309079&p=2072211#post2072211

Study the sections on carb adjustment and ignition timing. You will find detailed directions to adjust both.

 

[edu01jose]

Re: Black Max 200HP 1996 problems on idle

I'll try next time I go to the boat the spark test. Thank you friend

I tried searching for the manual but couldn't find anything on my motor.
I found the XRI model and a Jet model, I believe neither of those match mine.

 

[j_martin]

Re: Black Max 200HP 1996 problems on idle

Do yourself a favor and invest in some instruments. At the very least you need a tachometer and a water pressure gauge.

 

[edu01jose]

Re: Black Max 200HP 1996 problems on idle

I have multiple gauges, just that some of them don't work.
My water pressure gauge works perfect but my tach is broken and stuck at 6000RPM's (See pic)
My MPH works fine and I get 30MPH on my 23' excel at WOT.