56 Johnson 15 hp hard to start.

I did notice that the exhaust cover gasket is leaking some and I will fix that this winter if i can find a gasket.

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Model FDE-10
Got it back in May or June. Got the pressurized tank and replaced the diaphragm and gasket because it leaked out the primer shaft. Put new line on it too. As for the exhaust cover it dont look like its been off in a while. Looks like its been rebuilt at one time or another because the gaskets have no paint on them.

Ok here is what I checked. The choke seems closed all the way. Cant close it anymore with the lever on the side of the carb, with the choke knob pulled out. As for compression its 90 psi on both cylinders. The coils arent originals they dont appear to be very old. Look made from modern materials. As for the filter, it was cleaned before I started using it. May just have to get a new one or a different filter. It has always started like this since I have had it which is only about half a year but only ran it a couple of times. It runs great once you get it started. I had a problem with it earlier thought the prop was wrong came to find out the plug had too long of reach and was hitting the top of the piston. Got different plugs with a short reach and fixed that problem.

I have done everything I can think of. Checked the spark jumps a 1/4"+ gap, points at .020. Cleaned the carb twice. Tried different starting steps. Nothing seems to make it easier. It like 6 or 7 or sometimes even more pulls, hot or cold dont matter. Tank is pressured up pumped the primer every time to make sure that there is gas to the carb. I did notice that the exhaust cover gasket is leaking some and I will fix that this winter if i can find a gasket. Going to order a carb kit and new packing for the jets and see if that does any good. Any other ideas??

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(Carburetor Adjustments - Two Adjustable N/Vs)
(J. Reeves)

Initial settings are: Bottom high speed = seat gently (turn needle clockwise), then open 1 turn out(counter clockwise). Top slow speed = seat gently(turn needle clockwise), then open 1-1/2 turns out (counter clockwise.

Once you have adjusted the idle/slow speed needle and the high speed needles, then snug up/ tighten part numbers 83 and 89 with 7/16 open in wrench enough to feel resistance when you turn the needles, but not too much where it makes it very difficult to turn the needles by hand.

Setting the high and low needle valves properly:

NOTE: These settings should be done a large test barrel or on the boat in the water/lake!! It best to do these adjustment on the boat in the lake or on commercial size test tank. (You can damage your motor running it wide open in a small test barrel.)

(High Speed) Start engine (it will run pretty rough), shift into forward gear, take up to full throttle. In segments of 1/8 turn in (clockwise), waiting for the engine to respond between turns, start turning in the bottom high speed needle valve. You'll reach a point whereas the engine will either start to die out or spit back (sounds like a mild backfire). At that point, back out (counter clockwise) the needle valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest setting.

(Low Speed) Slow the engine down to where it just stays running. Shift into neutral. Again in segments of 1/8 turn in (clockwise), start to turn the top needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running. Eventually you'll hit the point where the engine wants to die out or it will spit back. Again, at that point, back out the valve 1/4 turn (counter clockwise). Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustments, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.

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