88' V6 Black Max getting up to plane

[andy6374]

Recently the engine has received many new ignition components including a trigger (you will see why I mentioned this later). I also did a carb cleaning and reassembly with new gaskets. This was all done because all of a sudden I couldn' get up to plane, engine bogged down and I also lost spark to 3 cylinders and could only get 12kts max. I ran it for ~3 hours at this speed for I had 13 nautical mile trip home.<br /><br />After performing the above tasks, the engine now has a "bad" spot in between no wake speeds and WOT. 2000-3000 RPMS seems to be the problem zone. The engine sounds different and shakes a bit more. These are speeds I'm hardly ever at. But, I don't know why this is happening. Also, after I've been up to plane this problem doesn't occur, unless I've been trolling for awhile, same thing happens.<br /><br />Idles superiorly and races like the best of them.<br /><br />Just hoping it isn't something major. Could the timing be off? Could the engine have been running lean on that long journey home? Should I stop obsessing about every little detail? (Sorry, never can happen.Just my nature)<br /><br />-Thanks <br />andy

 

[stant1man]

Re: 88' V6 Black Max getting up to plane

You mention you cleaned the carbs... Did you ensure when refitting that they were all set to open at exactly the same time? I had this problem on my old inline and im not sure if it applies to a blackmax but worth a look. Mine shook and ran poor through 2-3k then great, also idled great. Adjusted throttles and bingo...<br /><br />Stan

 

[andy6374]

Re: 88' V6 Black Max getting up to plane

Yep, the carbs are sync'd.<br /><br />-andy

 

[ronmold]

Re: 88' V6 Black Max getting up to plane

Have BOTH switchboxes been repaced?

 

[andy6374]

Re: 88' V6 Black Max getting up to plane

Nope Just one! You think that could be the culprit? If it is, then those darn switchboxes are the most unreliable units. I'm willing to be it probably is. Works good at idle, works well 3500+ RPMS, but sucks in the midrange.<br /><br />The real kisser is that you can't even test the switchboxes (other than spark or no spark)<br /><br />-andy

 

[JLEHighland]

Re: 88' V6 Black Max getting up to plane

I'm about to replace my 2nd switchbox for the same reasons, similar symptoms. I'll let you know how it goes.

 

[ronmold]

Re: 88' V6 Black Max getting up to plane

Replace them both with CDI units and re-time with a timing light. I found timing differences between factory merc and CDI units. I would never mix a merc & CDI switchbox. I had the same dead spot but once and a while at those "dead RPM's" something would kick-in and run fine just like there was a switch that someone would flip on and off!

 

[andy6374]

Re: 88' V6 Black Max getting up to plane

Thanks for the advice. I will re-time and replace switchboxes this winter. I am going to ride this thing out for the fall and get the rest of my fishing in.<br /><br />However, both switchboxes are merc. Just the stator is CDI.<br /><br />-thanks<br />andy