Guests - If You want access to member only forums on HSO. You will gain access only when you Sign-in or Sign-Up on HotSpotOutdoors.

It's easy - LOOK UPPER right menu.

Sign in to follow this  
Followers 0
huskminn

I need my 3rd cylinder back!!!!

10 posts in this topic

I have a 1999, two-stroke, 3 cyl, 40 HP Merc.

Two weeks ago, the motor ran fine all day. Last Saturday, it started fine, but when I went to head out on the lake, there was a serious lack of power and the motor didn't sound right.

Stopped, pulled the plugs and they were seriously in need of changing and one of them (#3) was downright a mess. I've never seen a plug fouled that badly.

So, docked the boat, drove to Cove and got three new plugs. Put them in, fired it up...same problem. So, we decided to fish it that way and stay close to shore.

Last night, I checked for spark in all three cylinders....it's there. When I pulled the new plug from #3, it was mess and looked like it was already 5 years old. There was a little oil/gas mixture that dribbled out of the cylinder. Obviously, it wasn't firing. I cleaned everything up, put in one of the cleaner old plugs and ran the motor. It seemed like it was firing once in a while. The #3 plug was warm, but not as warm as the other two.

I pulled it out, noticed no dribbling out of the cylinder, put in another old, unfouled plug and ran the motor. It definately ran better, but the #3 plug still didn't get as warm as the other two. It was a different brand and a buddy told me that different brand plugs will run at different temperatures.

I ran out and bought three new NGK plugs, gapped them and put them in. I am hoping that the motor will run now and I'll test that tomorrow night.

I have a theory that the #3 cylinder had so much dump in it that it just immediately fouled the new plug right after it was put in.

Any thoughts on this....similar experiences??

Tell me I don't have a bigger problem.

[This message has been edited by huskminn (edited 07-02-2002).]

Share this post


Link to post
Share on other sites

The 40 Merc has been a great troller for me. Runs down to about 1.5 mph in calm conditions. I think the excessive amount of trolling that was done two weeks ago may have contributed to the fouling of the plugs (I hope!!).

Share this post


Link to post
Share on other sites

I am not a mechanic, just experienced with problem solving for goofy things that go wrong over the years.

I had a motor once that had 3 cylinders and a similiar problem. I found out that the choke was stuck (choke cable fell off carb) on the one carb that was not firing properly, and all the carbs were basically out of tune.

Pull the cover off the carb intakes and inspect to see if everything is synchronized, and, who knows, maybe the carbs are just out of tune and might need professional tools to get them back in order.

Share this post


Link to post
Share on other sites

Take the third plug out and start the motor. This will bow all the gas and oil that built up. Put a new plug in and dont put the plug wire on all the way leaveing a 1/4 in gap. Start her up and and run for a minute, Turn it off and put the plug wire on all the way.

Share this post


Link to post
Share on other sites

I'm a user, not a mechanic, so I can't help. I do, however, own a 90 hp Merc (3 cyl) which is on my fishing boat -- Frankly, the 3 cyl is a rough runner at slower speeds even after tune-up (this is '98 equipment).

I have a 40 hp Merc (2 cyl) that sits on the back of my wife's pontoon for weeks on end, fires up when needed, and runs great at any speed from slowest to wide open.

Hope you get your problem resolved more inexpensively than I did -- I ended up buying a 9.9 hp Merc four-stroke as a kicker. I simply cannot troll with the 90, even though years ago I had a Merc 115 (6 cyl) that would troll all day on Lake Michigan. My what mysteries motors can be.

Share this post


Link to post
Share on other sites

i also had a 99 40 hp merc. and was cutting out in 1 cyl. brought it back to dealer and the problem was that merc uses alot of forma-gasket when they put there motors together and in the bottom carb a peice of gasket broke off and was sucking up in the main jet causing it not to run.
one day it run great the next day it did'nt after he removed all the bowls on the carbs and removed the tiny peice of form-a-gasket it was back to running like a champ!!!!
good luck finding the problem!!!

Share this post


Link to post
Share on other sites

Hmnnn......very interesting replies. Thanks for the input.

ST, I think I have succeeded in getting most of the build-up out of the 3rd cylinder by simply running it, removing the plug, putting in a dry plug, running it again, doing the same a third time. The last time I ran it, I checked the plug and it seemed to be in fairly good shape.......I think the build-up is gone.

Unless of course, there is a problem with the carb.....whether it be a piece of gasket or it is simply out of adjustment.

I'm going to try to run it tonight and we'll see if #3 runs as it should be.....if not, it's off to the shop. I am not a mechanic and I don't even want to think about messing with the carb.

I really appreciate the input....have a great 4th and don't forget to celebrate and take note of the freedoms that we have and that we must continue to protect.

Share this post


Link to post
Share on other sites

I hope the "build up" on your spark plug isn't aluminum from the rings. That would be a failure or clog of the injection system.


Otherwise, it sounds like you have excess oil in the #3 fouling the plug. Why that would happen is hard to diagnos unitl you tear into the carbs.

PCG

Share this post


Link to post
Share on other sites

After replacing the plug a couple of times, I took the boat out on Wednesday and it ran fine.......3rd cylinder fired as it should.

I also ran it on Friday with the same results. I'll pull the plug this week to check it for build-up, but it seems that the cylinder finally cleaned itself out.

Thanks for all your help.

Share this post


Link to post
Share on other sites

You might want to try some sea foam in there!

------------------
Hunt&Fish tell you drop!

Share this post


Link to post
Share on other sites
Guest
This topic is now closed to further replies.
Sign in to follow this  
Followers 0



  • Posts

    •   My Father-in-law (a master plumber) always used to say you only need to know 3 things to be a plumber:          sh*t doesn't run uphill         payday is on Friday         the boss is an ahole      
    • I've been getting them at Costco,  I've checked slyvee and sams but never see them.  Although one of the butcher's at slyvee says he can get them which might not be a bad idea since you can have some fat cut off before you pay per #. I picked one up a couple of weeks ago and it was about 2.80 a #, which isn't too bad yet considering bacon in the store can run quite a bit more than that.  You making bacon or doing pork belly burnt ends moon lake?
    • Excellent summer fishing.  Charters catching strong numbers.  Jig/minnow or jig/leech and bouncers with spinners with crawlers or minnows still producing walleyes. When the wind is right for pulling spinners, they have been lights out.  Walleyes being caught in varying depths, 7-31' of water.  Some shallow shorelines still producing. Pike mixed in all over the lake.    Walleyes in the Rainy River with a better morning/evening bite.  Trolling cranks or pulling spinners a good idea to cover more water. Smallmouth bass are out and about along shorelines and feeder streams. Sturgeon fishing opens again Saturday, July 1st.     Up at the NW Angle, water temps are in the low to mid 60’s. Wind blown shorelines are giving up walleyes via leeches or crankbaits along the weed line. Crawlers on a  gold and/or orange spinner are producing fish out of the mud between 22 - 26 feet. On the Canadian side, bottom bouncers and spinners have been filling the livewells outside of monument bay between 24-28 feet.  Jigging near Skeet and Kennedy Islands have produced nice sized walleye and numerous perch. Great smallmouth action in Tranquil channel and the mouth of Johnston passage. Muskie fishing picking up with high 40” class fish being caught with a few 50's from shallow bottom bays or adjacent to them.
    • Busy time of year out there so if u get canceled it is hard to rebook especially with the smaller operations. Bummer though as it can be a lot of fun if they are biting. 
    • I understand that you never really know when the Warriors are going to fall off or if they even will.  Hopefully the Wolves can make the playoffs and gain some experience, maybe teach the rest of the team how to play defense, so that in a few years we are knocking on the door and can lure in a top free agent to put us over the edge.  Its just an awful tough time to be a good team right now with the Warriors so clearly heads and shoulders above everyone else.
    • I couldn't have said it better myself pikestabber!  We have to go out there and do what we can now and not try to set up for "when the warriors are old" cuz the way the NBA is going who knows what players may join forces to set up the next "Warriors" squad.  Heck maybe the Wolves will be that next team !!  I just really love the addition of Butler and from the sounds of it we are not done yet and I am excited to see what will happen in free agency and if we could really land the likes of Kyle Lowry one of the other PG's that are hitting the FA market.  Nice to see the Wolves making moves!!
    • I would ask Getanet where to get some good ones!   Pork Belly Stinks Started by Getanet, May 1
    • So that means you ALMOST caught a fish!!   Real bummer!
  • Our Sponsors