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1991 Johnson 9.9 - 2 cycle pull start

G

greenvilleguy

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Engine set up for a year. Got it started on muffs and starter fluid. Took it to the lake and it took about 1 hr and a 1/2 to get it to crank -- finally had to use starter fluid. I ran the boat up and town the lake and the motor ran great.

I brought it home and have rebuilt the carb. It still doesn't want to start. I'm assuming since it ran great on the lake after getting it started that the problem is in the fuel system. I'm thinking the fuel pump must be OK for it run good after it's started.

Where should I go next?
 
Since the motor run great after it starts, I guess you are thinking it might be sticking. I'll put an OHM meter on it tomorrow and make sure it's functioning properly.

Thanks.
 
Kill switch is good. Spark is good. I pulled the fuel line from the carb and fuel getting to carb. Tried to start -- no luck.

I pulled the carb off again and there was no fuel in the bowl. I took apart and reassembled, hooked up the fuel line and primed. This time I had a couple of caps fulls of fuel in the bowl. I'm wondering if the float was restricted by either the little tube or the nozzle well (little white plastic thingy in the middle of float). Anyway, float seems to be working now.

While I've got the carb off again, I've sprayed carb cleaner in every hole I can find. Anything else I should do before I put it back on the engine?? To get the carb off, I had to take the rope starter off and it's a real PITA to get back on so I'd like to do all I can before putting it all back together.

By the way, when I rebuilt carb originally, I didn't find any clogs or crud. I expected the float pin to be worn, but it was fine.
 
Model # of the motor?-----And post the actual compression test values here.-------Does spark jump a gap of 3/8" or more ?
 
1991 Johnson 9.9 Model J10REIR.

I don't have a compression tester. It ran great after cranking the last time I started it. Would this indicate good compression? Should I invest in a compression tester?

I have the plugs gap at .030 per the manual. Are you suggesting I open them up to test how strong the magneto is? Please explain.
 
Sparkplugs are not used when testing maximum ignition output.-----Use a test device.-----Good luck with your motor.
 
OK, I've reinstalled the carb and starter assembly. Now the motor starts, runs about 5 to 10 seconds and stops. I've tried to push in the choke, leave it out half way, etc. I've also tried to adjust the low speed adjustment and that does seem to have an effect on how long it runs -- but it still dies.

This problem is new to me. Before, if it fired; it ran. Unfortunately, the model doesn't allow me to open the throttle while in neutral so I can't try giving it more gas while it's running.

Could it be that the fuel pumps isn't pumping fast enough? I'm not priming again between times. Any thoughts??
 
Do as instructed earlier. Buy, or borrow from a parts place a decent compression tester. You can make a spark tester, or buy one for about $10.
Those are the 1st steps, (and the most important, & cost almost nothing).
If both are good, then look into fuel supply. Try a known good different tank. If pumping the bulb keeps it running, then look to fuel pump issue.
I have a small lawn mower tank attached to a stick, with a clamp at one end. I hook it directly to carb. It will gravity feed, & if motor runs fine, it’s the tank or fuel pump.
Here’s homemade spark tester.
 

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Thanks. I bought a compression testers with the following results:
Top cylinder - 88
Bottom cylinder - 95

Johnson doesn't publish what they should be, but I know they should be within 15% of each other and they are.

I purchased a spark tester as well. It fit between the plug and plug wire. Both cylinders tested good.

That leaves me with the fuel system still. I went down and tried it again with the same results. It fires right away, runs for about 5 seconds and stops. I don't have time to pump the bulb to see if I can keep it running that way. With the fuel line to the carb off, I can run fuel from the tank through the fuel pump by priming.

I'm thinking that the flow into the float bowl is somehow restricted. I can only think of three possibilities:
1. The float isn't dropping enough to completely fill the bowl.
2. There is an air leak somewhere.
3. Fuel pump needs to be rebuilt.

Should I just go ahead and order a fuel pump rebuild with new hoses and clamps?
 
I would find someone to pump the bulb while you start it. That fists nothing. Throwing parts at motors, without determining the real problem gets expensive.
If you do decide to rebuild, or buy a fuel pump, pay for OEM, do not be tempted by cheap EBay units.
 
Got my wife the pump while I tried to start. Same result so I'm assuming that's it's not the fuel pump.

Took the carb off and the bowl was full of fuel. The little tube that runs from the nozzle well had come off. The one in the carb kit from Sierra wasn't as tight a fit as the one that was on it so I went back to the old one. The nozzle well now fits better inside the float so I'm thinking I've got it solved.

I will put it all back together Tomorrow and try it.
 
OK, still won't start. I've always believed that if you have compression, spark and fuel, it should start. I have a couple of questions:

1. Is my compression (about 90 lbs per cylinder) good enough? I watched a YouTube today on a compression test of a similar engine and his was 120.
2. If the float bowl is full of fuel, should the engine start regardless of the condition of the fuel pump?
3. My spark tester says my spark is good. Does that include the plugs? How about the points?
 
There are no points on that motor!---Orange and blue wire on the top coil?------Put 5 drops of fuel in each cylinder.----Try and start it.-----Report what happens.
 
Question #2
No. The bowl can be full, but if fuel does not get transferred, (in the correct amount), to the cylinder it will not run.
 
racerone said:
There are no points on that motor!---Orange and blue wire on the top coil?------Put 5 drops of fuel in each cylinder.----Try and start it.-----Report what happens.
Click to expand...
racerone said:
There are no points on that motor!---Orange and blue wire on the top coil?------Put 5 drops of fuel in each cylinder.----Try and start it.-----Report what happens.
Click to expand...
OK, The first time, it tried to fire but didn't. I tried a second time with the choke, squirted more fuel in cylinders and this time, it ran for a second or two. For a while, it would fire when I pulled, but eventually stopped firing again.
 
racerone said:
I think you need to look at the carburetor / choke again.
Click to expand...
Yes, I thought it would be a simple matter of rebuilding the carb and it would be fine. I've now had the carb off 4 times, each time cleaning out all the orifices with carb cleaner. Obviously, I'm out of my depth. I don't see anything wrong.

I did notice fuel in the lower air box like the fuel went the out the throat instead of back into the engine. Could the throttle linkage not be opening the throttle plate?
 
IT'S RUNNING!

Thanks to all that offered advice during this journey.

I adjusted the throttle linkage to allow the throttle to be opened slightly more. My motor doesn't allow the throttle to go beyond idle speed in neutral and you can't pull the rope in anything but neutral.

I also adjusted the low speed idle needle to 2 1/2 turns per Seloc specs. (3 turns seems to be the sweet spot.)

My motor was tilted backwards causing fuel to run out the front of the carb into the air box so I turned it around.

I'm not sure which of these was the solution. All I care about now is that it works great!
 
OK, Last post on this thread. I did the "Link and Sync" thing and the motor is running better than it has in years. I had figured out that I wasn't getting enough fuel into the cylinders because the throttle wasn't opening at start. Turns out that to properly adjust the throttle on this engine, you adjust the cam roller and when properly adjusted, that opens the throttle.
 
The purpose of link & sync is to co-ordinate throttle with timing.
Throw that Seloc manual into the fire starter box. Purchase an online factory manual, they’re not much money & will save much grief.
 
Yes, agree the purpose of "link & sync" is to speed up timing as you add fuel. They have to be together. In my case, they were way off restricting the throttle from opening in the start position.

I have no idea how the timing got so far off, but it did. Getting the cam roller lined up with the mark on the cam roller plate solved the problem. I had to shorten the throttle linkage to get the cam roller back to the mark and then adjust the cam roller screw so the cam roller made contact. (Sorry to say, I have no idea what the Seloc book says to do.)
 
The most common cause there’s a plastic bushing around the roller. That bushing cracks and falls off. That results in a much smaller diameter and as you twist the throttle, the timing plate moves, but doesn’t contact the “roller.”
Either build up the roller to proper diameter or buy a new part
 
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