Engine trouble at high RPM

A forum for discussion of how to rig and tune your boat or kicker to achieve the best sailing performance.
User avatar
Dimitri-2000X-Tampa
Admiral
Posts: 2043
Joined: Fri Jan 02, 2004 5:36 am
Sailboat: MacGregor 26X
Location: Tampa, Florida 2000 Mercury BigFoot 50HP 4-Stroke on 26X hull# 3575.B000

Post by Dimitri-2000X-Tampa »

Chuck, thanks for the encouragement. Earlier today I did happen to open the drains and squirt carb cleaner in there but it didn't fix it. Unfortunately, mine is running worse now than when I first started this thread, I can't get more than about 2-2500 RPM so I'm pretty much down to a carb job. The tank was seriously contaminated, don't know how it got that way as the other 3 are not too dirty. I've got the tank cleaned up now thanks to Billy's suggestion.

I've got nothing to lose by trying to run it tilted up for a while so I'll try that tomorrow before I give up and de-rig. It seems pretty blocked up, maybe 2 or 3 jets are clogged up. I'm hoping I can dissassemble it without undoing the adjustments...just clean out the jets and put it back together...sounds like that's what Tony did.
User avatar
Dimitri-2000X-Tampa
Admiral
Posts: 2043
Joined: Fri Jan 02, 2004 5:36 am
Sailboat: MacGregor 26X
Location: Tampa, Florida 2000 Mercury BigFoot 50HP 4-Stroke on 26X hull# 3575.B000

Post by Dimitri-2000X-Tampa »

Here's the conclusion to this saga and also where I've been the last few weeks.

I tried some more liquid cures to no avail so I pulled the boat out at the end of January. On 2/6, I finally had some time to pull off the carbs and open them up. After 3 carbs with no problems, I found the blockage in the main jet of the 4th carb. It sure was nice to have found it and I went to bed thinking I would put the carbs back together the next day, but that wasn't going to happen. Early the next morning, I got the proverbial call; my 67 yr old mother had a bad accident and was in a coma. I went to Virginia where she was and then found out that she also had a massive stroke. She passed away a few days later on 2/13.

Three awful weeks later, I'm back in Tampa, so I decided it would be good to put the carbs back together after cleaning them and replacing 4 o-rings that had crapped out. The rebuild kit was going to be like over $200 so I just got $4 in o-rings instead since everything else seemed to be in good shape. Anyway, I put her back in the water today and the motor runs like a champ, probably the best its ever run. Got 200 more RPM at WOT than I ever did even before the carb got clogged. Everything seems to be smooth and synchronized too which is good because I didn't want to have to find one of those 4-way MP gauges. It will be good to go sailing again.
User avatar
TonyHouk
First Officer
Posts: 278
Joined: Wed Jan 07, 2004 3:36 pm
Sailboat: MacGregor 26X
Location: My New Hometown, Fort Mill, S.c. "98 X with a '95 Evinrude 115

Post by TonyHouk »

Dimitri,
I am saddened by your misfortune. I will keep you in my prayers. May God be with you and your family at this time.
I am glad to hear that you did get it running. I did not have to use a synchronizer on mine either. I guess I got lucky. happy sails, Tony
sailpsych
Chief Steward
Posts: 95
Joined: Thu May 20, 2004 1:29 pm
Location: Oxnard, CA

LOW QUALITY FUEL

Post by sailpsych »

For what its worth...
Newby Mac guy here.

I have owned and run motorcycles for more than 20 years now. Noticed that quality of fuel, apart from the dirt in it, can have a drastic impact on restarting engine and performance. Here in California I have noticed a drastic reduction in the fuel mileage and power my motorcycles have over other states. The fuel seems to go "sour" quicker too.

Any other thoughts along these lines?

BG
User avatar
Dimitri-2000X-Tampa
Admiral
Posts: 2043
Joined: Fri Jan 02, 2004 5:36 am
Sailboat: MacGregor 26X
Location: Tampa, Florida 2000 Mercury BigFoot 50HP 4-Stroke on 26X hull# 3575.B000

Post by Dimitri-2000X-Tampa »

I'm not sure how much fuel standards can vary from state to state but I wouldn't think it would be too much otherwise engines would not run consistently well across states. It certainly is important to keep your tanks clean, I learned that the hard way.

For the posterity of this thread, a few weeks ago, I ended up forking out 50 bucks for a mercury synchronizer because my 50 HP Merc started not idling so well. The adjustments are extremely fine and the screws were very loose. They have little springs to keep tension on them so they won't turn, but they looked too loose to me. I got the carbs synched and then put some silicon sealer on the screws and let it harden overnight before I used the motor. Hopefully, the screws won't move and the carbs will stay synched now. It idles much better with the sync job.
Post Reply