68 mercury 200 (20hp)

[Arkman]

I'm sitting at the cabin with a motor with no power. today I changed out the fuel pump diaphram and now I have about 10% of full power. it was a very simple deal to change it out, but I could have messed it up. I also noticed than the gasket on my carb that is right by the screen is all ripped up. could that be the problem? sorry for the bad typing im on a cell phone.

 

[JGra]

Re: 68 mercury 200 (20hp)

Is there anywhere you can get a piece of clear fuel line? Install it from the fuel pump to the carb. This will allow you to see if you are running out of fuel or if you get alot of air bubbles, you might be sucking air. Also try pumping the fuel bulb whille running. Let ke know how thing go.

 

[Arkman]

Re: 68 mercury 200 (20hp)

ok, a little more info. it starts good. idles a little rough. I shift into reverse no change same idle and all. shift to forward and it wants to die unless I give it gas.I can get a 1/4 turn on the trottle before it feels like its going to die. the bulb gets a little soft but if I pump it there is no change. the only thing I did was change the fuel pump diaphram. which I had to take off the internal fuel lines to do.

any thought? anyone?

pretty soon i'm going to have to borrow jgra's shotgun.

 

[Arkman]

Re: 68 mercury 200 (20hp)

I cleaned the carb and replaced that gasket with no change. I think I might try a new gas tank. that is the only fuel related thing that is still old. if that doesn't work I will try that clear fuel line to see if that's it. it might be the fuel lines that I made. they don't have the best seal around the fittings. I just don't know how to make that better. maybe some better hose clamps.

does anyone have any ideas? it run mostly fine at loew speeds but doesn't really like to idle. im really lost!

 

[JGra]

Re: 68 mercury 200 (20hp)

I just used some brass elbows and barbs and small hose clamps to make mine. Make sure you dont have any kniks in the lines. What do you have your mixture screw set too? should be somewhere around 1 1/2- 2 turns out. One thing to check, one day when i was working on the motor I went to start it and it ran really bad then would not start. After messing with and taking the carb apart I could not find anything wrong. I took a fuel sample and found a bunch of water in the fuel. take a fuel sample in a clear bottle and let it sit. If there is any water in it it will settle to the bottom. As far as the fuel tank goes I had to replace all the tank fitting at the tank and eng. They looked good but were not sealing real well. The fuel bulb also looked good but the check valve in it was bad. I also fished the the line in the tank out and cleaned the screen on it. On the carb did you take all the brass tubes and all the jets out. I used a can of carb cleaner with the straw to get into all those little passages. Try the clear hose deal. This will tell you if you have a fuel supply issue (line runs out of fuel or air in lines) or a carb issue (line stays full of fuel with no air bubbles). Let me know how it goes. Good luck.

 

[Laddies]

Re: 68 mercury 200 (20hp)

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[Arkman]

Re: 68 mercury 200 (20hp)

I don't really know how to check the spark bu it feels like they are both good. I could be wrong though.

when I cleaned the carb I took apart everything I could and cleaned it 3 or 4 times with carb cleaner. as far as I can tell I do not have any kinks in the hose. I pulled the hose of the carb and it hd good flow when I pumped the ball. I reploced the fuel lines between the motor and the tank but I haven't done the tank or motor fitting yet. I think I will try that clear hose today. I might go buy a tank and new fittings as well. im on the lake so I would like to try as much as possible while I cab still test it. oh, and the carv was set to 3.5 turns, that's what it was when I took it apart the first time. i'll try that first.

thanks!

 

[Laddies]

Re: 68 mercury 200 (20hp)

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[Arkman]

Re: 68 mercury 200 (20hp)

Laddies- I'm not sure what you mean. What is the ground electrode? I'll do a search online to see if I can find the process for doing it. I don't really know what I'm doing with outboards...just stumble my way through it. Thanks for the info though!

So earlier this year I replaced my fuel line and bulb but used the old fittings. That will be the first thing I try. I could stand to get new fittings anyways. I'm having trouble finding a fitting for the inside of the motor. The only ones I can find do not have the holes to screw them in. I'll keep looking. I messed around with my tank and it seemed to make it worse. Which is good, I changed something....even if it did make it worse. Its a change. I'll keep you posted on what I find. Even with a 20hp motor that acts like a trolling motor I got out and did some fly fishing. Caught a bunch of largemouth and a ton of sunnies...all and all not too bad!

Thanks for the help!!!

 

[JGra]

Re: 68 mercury 200 (20hp)

Take the plugs out of the eng and put the one end back on the spark plug end. Hold it up against the side of the eng somewhere and have someone pull the pull start or spin the eng over. Just be sure you are not touching anything metal on the eng or you will get a shock. As for the fittings I bought everything from wal mart. I thin the brand they sell is OMC. I bought the one for the mercury motor and it has the end that goes on the eng which has the 2 mounting holes and the one that goes on the tank. All comes in the one package. I think it was around 12 dollars. Dont give up on her just yet. Oh, did you get to try the clear fuel line? Let me know

 

[Arkman]

Re: 68 mercury 200 (20hp)

Bad news. I'm missing spark on my bottom cylinder. I think I still have a fuel problem though. Maybe not. If you are only running one cylinder will the bulb go soft? Mine was really soft when I was running earlier, I couldn't keep it hard.

Now what do I do with the no spark. I'm not really sure what that means. Where do I go from here?

Thanks!

 

[Laddies]

Re: 68 mercury 200 (20hp)

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[Arkman]

Re: 68 mercury 200 (20hp)

How do I test the coils? I have found the points and condenser, are those hard to replace? I'm getting to know my way around the motor but still a very beginner at this stuff.

Thank you so much for the help! Even though its not really the answer I wanted

Thanks again!

 

[JGra]

Re: 68 mercury 200 (20hp)

I know there some tests you can do for the electrics on these. The manual should be able to tell you those or hopefully someone will respond with them. If it were me I would take the top cover off and swap the coils ans see it the problem follows from one cyl to the other. That would be a way to test the coil. Also may be one of the points or condensors. I think there are 2 of each but I am not sure. For that suff you will have to pull the flywheel off. You will need a puller to do that though. If I can help in any way just let me know. Wsih I had some better answers but I am still learning this motor myself. I would take care of the spark first before I look at the fuel. You may not have a fuel problem at all.

 

[Arkman]

Re: 68 mercury 200 (20hp)

So where would I find this tool to pull the fly wheel off? What do you call it?

Thanks!

 

[JGra]

Re: 68 mercury 200 (20hp)

You should not need to pull the flywheel to swap the coils just to get to the points and condensors and the other electrics. I would try swapping the coils first. The puller is just a standard puller that can be bought just about anywhere that sell tools. Just make sure you get the one that lets you screw into the flywheel and not Jaw type puller that grabs the outsides of it. A normal automotive harmonic balancer would work ok. They are not expensive.

 

[Arkman]

Re: 68 mercury 200 (20hp)

I'm glad to hear that its not too expensive for the puller. I'm going back and forth between looking for something else and fixing this up. I dont think I can let go of it. Found it in the garage 12 years after my dad died, so it sort of means something to me.

Anyways. If I switch the coils and the one plugs switch which one was working should I replace the points and condensers anyways? I know that its dumb to not spend the money to take care off it but I also don't really have the money right now. So if it is necessary I might just let it be for a while and not use it.

Let me know what you think. Thanks

 

[Arkman]

Re: 68 mercury 200 (20hp)

I'm thinking about all the issues I have now. If I'm running on one cylinder would that hurt anything. I plan on fixing it before I use it again, I just want to make sure that I shouldn't be checking for other damage.

Second, would only one cylinder cause the primer bulb to go soft while running? As I was poking along to the boat landing I couldn't pump it fast enough to keep it firm.

If that is the case should I try to troubleshoot both these problems at the same time? Replace the tank and fittings and deal with the no spark issue?

 

[JGra]

Re: 68 mercury 200 (20hp)

I would first tackle the lack of spark problem. Mine sat for about 15 years and I did not change the points or the condensors. Try swaping the coils first. If the lack of spark moves from one cyl to the other then you know you have a bad coil then just replace the coil and go from there. It would not be real good to run it just on one cyl. You will have alot of un burnt fuel going thru the motor which could wash your cylinder wall. Try the coil swap first. I have learned when diagnosing a problem its better to fix one thing at a time. That way you know what works and what dont. The lack of spark on the one cyl could be causing the soft fuel bulb but I would not worry about that untill I got bot cylinders to fire.

 

[Arkman]

Re: 68 mercury 200 (20hp)

ok, thats what I would normally do. One at a time. I figured if there was no chance at all that it could cause the soft bulb then maybe I would do some fixes there, since it could cause it i will leave it until I get spark back. I might try to switch the coils tonight. I'll let you know how it goes.