1961 Merc 700 E, compression and spark good but fizzles out, won't idle

apson

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Joined
May 27, 2011
Messages
20
When I had the lower unit off, I got it to idle after only a few tries...quickly turned it off as there was no water; didn't rev it up or anything. Once I installed the impeller kit, reinstalled the lower unit and placed it in the water it was like I couldn't get it to idle for more than 3 seconds. Any attempt to increase throttle (via control box/in gear) would slowly bog it down after a couple seconds and kill it. I've installed the fuel pump gasket and membrane kit but haven't really touched the carbs. Engine has been sitting since 2007. I didn't see anything bad when I had the fuel pump apart but I'm wondering if some nasty stuff is going on inside these carbs/floats/seats. The gas tank was very clean so I thought I might be lucky and have an outboard stored without fuel in the system.

I currently have a little sea foam in my tank per instructions on can, on the low ratio side, the tank is very clean, and have my fuel oil ratio 40:1. Replaced inline fuel filter. Also followed some instructions about waking a sleeping outboard and dropped some of the 2-stroke oil directly into the cylinders as a precautionary measure.

Is there a way to somewhat clean the carbs out without uninstalling them? I have 2 carb kits but need a third. They are the Sierra kits for what I believe is a type KA (18-7013). I don't mind rebuilding them myself but I'm still waiting on a manual I ordered almost 2 weeks ago.

In other news, my tell tail was flowing :)

Compression appear ok? Here are the results:

compression.jpg
 

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: 1961 Merc 700 E, compression and spark good but fizzles out, won't idle

Dirty, restricted idle circuits, not flowing enough fuel to keep it alive at an idle.

Wal-Mart super tech carb cleaner in the spray can works will to cut thru gunk, mineral, and greasy oil deposits, HOWEVER, nothing works as well is a complete tear down and cleaning, blowing thru EVERY passage, to get the carbs clean.
 

apson

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Joined
May 27, 2011
Messages
20
Re: 1961 Merc 700 E, how to remove distributor for top carb removal

Re: 1961 Merc 700 E, how to remove distributor for top carb removal

I've decided to clean/rebuild the carbs. I have much of the carb section of the shop manual from maxrules.com but I am missing the "remove the distributor" section. From the top down I have the adapter then the collar assembly. It's this collar assembly that prevents removal of the top carb. If one just wanted to remove the top carb, how much/where on this distributor do I remove it? It seems like it would either be removing the adapter from the distributor arm on the block OR removing the collar assembly from the adapter.

The manual I ordered from repairmanuals4u.com is going on 2 weeks...aye.
 
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jayboy76

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Joined
Mar 6, 2011
Messages
27
Re: 1961 Merc 700 E, how to remove distributor for top carb removal

Re: 1961 Merc 700 E, how to remove distributor for top carb removal

A good carb cleaning is probably going to take care of it but let me tell you about an incident I just had with a brand new dual cylinder mower. When I got it in late March I put new gas in it. What I didn't know was the dealer had put gas in it and then it sat for several months before I bought it. It started running rough within 3 hours of use. I found little gum balls in the bottom of the tank, luckily it had a wide mouth filler cap so I could fish them out by using a paint stir stick. Then I cleaned the line and replaced the filter. With the help of the warranty shop I went ahead and cleaned the carb but still didn't run right. The shop had a 4 week back log. Finally got it in the shopthis week and I only had one cylinder running. The intake valve had stuck from the gummed up gas and bent the push rod on the valve lifter They replaced it and runs like a champ now. I'm almost sure the dealer (not a mower shop, just a military BX retailer) did not put stabalizer in the gas and it probably was just a small amount of gas. But just goes to show you how bad our gas is now days and the importance of using stabalizer right away.

Good luck on your cleaning and rebuild.
 

apson

Cadet
Joined
May 27, 2011
Messages
20
Re: 1961 Merc 700 E, how to remove distributor for top carb removal

Re: 1961 Merc 700 E, how to remove distributor for top carb removal

I finally got my carbs off. Turns out that the trick is just removing the actuator assembly so you can spin the rotor assembly a bit to get the second bolt out. The top carb's bowl was dry, dry dirt on the screen and dried out crumbling fuel screen gaskets. I think my troubles may have been caused by a lack of fuel to cylinders one and two ;)

I'm going to replace all this old fuel line while I have everything apart but I'm still trying to figure out how you all make such nice hose fittings.

I'm also going to revisit the fuel pumps and conduct the blow test to make sure their check valves are working.
 
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