Engine won't get past 1500 rpm

[bluedolphin]

Hi, guys! I'm back! The engine exhibited something different this time - she stalls when going from forward to neutral, or neutral to reverse, or reverse to neutral, etc.!!! What the .....? Here's how the last couple of days went. I told the mechanic that, leaving the shop the other day, I started backing off the dock, and as soon as I moved the lever from reverse to neutral to go forward, the engine stalled. The engine did not start right away, but I finally managed to get it started. When I got to my dock, I had to turn around, so I put the engine in neutral, before I put it in reverse. As soon as I moved the lever from neutral to reverse, the engine stalled. Again, I had some difficulty starting back up, but I finally managed to get it going again, and go forward. When I got close to the dock, I put it again in neutral, and she stalled again!! Fortunately, I have some lines on the dock that I can grab and hold the boat in place and tie up. I called the mechanic, and he will take a look the next day. Update after the mechanic's visit.

[bluedolphin]

The mechanic came by and adjusted the timing. While tied up at the dock, he put the engine in reverse, and it did NOT stall. He kept it in reverse for a good 2 minutes to see if it will stall. It did not. He moved the lever to neutral, to forward, to neutral, back and forth, and the engine did not stall. After he left, I felt relieved that maybe, my boating is back. I took her down the river, and got her up to 4100 rpm, got back to the dock and tied up with no problems. GREAT STUFF!! I'm happy again. In the afternoon, I decided to take her out again, this time, all the way to the inlet. Long story short, the inlet (Port Everglades) was nasty, but I managed to stick her nose past the break water, and then I turned back as soon as I safely can. I was only going 2000 rpm, but the bow will rise 3 or 4 feet, and the the boat will drop 3 or 4 feet, nose first! Forecast was 1 to 2 feet, but I guess the inlet is always dangerous. Plus there's someone sea trialling a 30 footer and charging through the inlet, and he crossed my bow 100 ft away, so the effect on the waves in the inlet got even more scary!!! I prayed, kept my life vest on, kept the bow into the waves, and somehow managed to get her back in. Anyway, the story does not end there. When I got back to my dock, the stalling started again. DAMN, why is this happening to me??? What could it be this time? I called the mechanic again - he will come by to have a look at it the next day.  Update to follow!

[JimCt]

Nothing like a good mystery!

  (Glad I'm not paying to find out how it ends...)

[bluedolphin]

This time, the mechanic increased idle speed to 1000 rpm, checked to see if it will not stall from neutral to reverse, etc., and it did not stall. I was not home at the time, so told him I will try the next day, and hopefully, the problem has been solved. We'll see. I'll take her out in the morning, and report the results, hopefully a positive report.

[JimCt]

Simply increasing idle RPM may be masking the root cause of the problem.  You're sure compression is good?

[bluedolphin]

We checked compression, it was ok - lowest 105, highest 110. That was 2 weeks ago. I'm not feeling good about increasing idle, either. Like I said, I got the boat in October 2006, no problems until about a month ago. The same mechanic has done the following: 1. Changed impeller ( routine maintenance). 2. Replaced broken throttle pin (??), I don't know what it's called. Without it, the engine will not go forward or reverse past idle. 3. Replaced tilt/trim assemble, will not tilt up, frozen in the down position. 4. The dreaded "will not go past 1500 rpm" problem, which I believe is fixed. and now, 5. Stalling problem. Do you guys think there's any connection between these problems/fixes? Is is time to go to an authorized Mercury shop????? Time for an expert 2nd opinion? Thanks for all your input, but I'm convinced, even with a detailed manual (which I have) that I don't have the ability to diagnose, much less fix these problems myself. And I'm not sure this latest problem will go away after increasing idle speed. HELP!

[GoneFission]

I am not one of those "dealer junkies" - in fact I prefer to do work on my own stuff whenever I can.  But - Mercury makes an ignition tester for their motors and it's only available in Mercury dealers or authorized repair centers.  The Thunderbolt III and IV systems, as well as the EFI systems, really can't be tested without the right diagnostic equipment.  

My 200 V-6 was doing the "not over 2000 RPM" thing intermittently early last year.  I took it to the Mercury dealer, who tested it and told me right away that one switchbox was failing and one rectifier was out.  It was not cheap - $500+ for the repairs, but the motor was running good as new when I got it back.  I bought another switchbox for $50 on eBay to keep as a spare (new ones are $250) - just in case...  

So my vote would be to go with an authorized Mercury dealer or repair center - you've spent way too much time and money to fix things that probably did not need fixing.  Find a big Mercury shop that does lots of service work and I bet they will find the problem and fix it pronto.  

Good luck and hope to see ya on the water with the hammer down!!   :twisted:

[JimCt]

Go to the Merc. dealer.  They have the diagnostic tools.

Other thing about setting the idle high is it's harder on the gearcase dogs when you shift.

[RickK]

Find a big Mercury shop that does lots of service work and I bet they will find the problem and fix it pronto.  

I think that is a BIG hint there and I agree - little shops and big problems (even if they don't seem like they're big) don't mix. I know that there are some really good mechanics out there, but if they can't afford(or can get) the test equipment, it's repair by replacement - that sucks. You just can't beat a big shop. Been there, done that.
Now for the easy stuff, I'll do it myself, i.e impeller, plugs, thermostat, filters - the everyday stuff.

[bluedolphin]

One thing I can say about Aquasports, there's always a lot of interest, if the boat is in decent shape. You've all been a part of my ignition problems, and I want to say, Thank You for all your help and encouragement. But sad to say, I've made up my mind to go back to inboards. I posted my Aquasport on Craigs List Ft. Lauderdale on Sunday July 8th. A neighbor 2 canals away called me to look at it on the same day. My wife and I were on the boat coming back on a fishing/cruising trip, and the boat was running fine. I showed the boat to my neighbor, and he said his brother will share the purchase of the boat, so the brother will come and look at it another day. Monday, I got a call from Tampa Bay, he says if the boat is in pristine condition, he will bring cash on Friday(2 days from now). Tuesday a guy came with his family from Pembroke Pines (an hour away from me) to look at the boat, said he will think about it. Same day, another guy said he's off Wednesday (today) and he will come by to look at the boat. He ended up buying the boat today - he gave me cash and I signed the title to him at 7:30 p.m. today. Before he came, somebody else from Daytona Beach called to see if he can come by on the weekend. 5 callers within 5 days, and one of them bought it. WOW!!! I guess I priced the boat right - asking $5k with trailer, accepted $4k cash. I had to call the guy coming on Friday to tell him the boat is sold, and he was pissed. I told him he has not given me a deposit, and this guy gave me cash. Now on to my next boat - a 1984 Shamrock 20' cuddy cabin, single inboard. I'm looking at it Friday morning, might make a deal same day. I may have another boat before the weekend. Is this tiring you all just reading about it??? Anyway, Aquasports rock, there's always going to be buyers, so hold on to them as long as you can. As long as they don't become problematic ($$$$$'s) like mine.

[RickK]

Sorry you had those aggravations.  Keep your eyes open (and here) and maybe an inboard or i/o Aquasport will appear that will grab your interest.
Good luck.