1979 80 HP running in gear

[heyblue]

Idles on muffs.
Idles in the water fine also.
Put in gear and it is like the ignition was turned off
Other info. need to put idle lever almost full on to start cold or in water
I have tried the opening of carb idle jets wit no change.
It did run in gear once this last time I tried, but moments later put in neutral then back in gear, BAM off it goes.
Back on muffs it starts and idles fine, even put in gear, though I do not have it in a barrel of water.
any ideas.

 

[racerone]

Idling in gear on the hose there is no load yes.-------In gear on the hose is still essentially in nuetral yes.----Check compression and check to see if there is spark on all 4 plug leads.----Spark must jump a gap of 7.16" ( 1 cm ) to be considered " good spark "

 

[Mi duckdown]

what racerone posted

 

[heyblue]

Compression good. Using a spark gap checker, got about .8mm on 2,3n +4, got a full 1mm on 1.
Seems like the problem is a little related to temperature. Stating cold need the idle arm near full, after warm up can reduce idle to norm. Seems to be missing while cold at fast idle, and stalls at normal. Motor has new plugs and plug wires. This is all on muffs. This engine does not have a thermostat, and since I use it in the Santa Cruz, CA area in the ocean (water temps in the low 50's this time of year) it will not get warm. Any ideas.

 

[MH Hawker]

rebuild the carbs

 

[racerone]

Will spark jump a gap of 3/8" or more on all 4 leads.----Proper spark and a proper test is essential to outboard repairs.

 

[heyblue]

As I posted getting .8mm which is about 5/6 16th i.e. about 3/8 tested using a spark gap tester, where I can adjust the gap and see if the spark jumps. This test was done at cranking speed.
Carbs have been rebuilt recently. I also dissembled and rechecked the float adjustments recently on both and rechecked all opening and pathways in the carbs again.

 

[racerone]

Start the motor and pull one plug lead off at a time.-------------What happens then ?--------------This may also be as simple as carburetor adjustment.----Open the low speed jet 1/4 turn at a time and test again.

 

[heyblue]

I will try pulling each plug wire one at a time, though need to get a good pair of rubber gloves, since the spark on all cylinders is good and strong.
Please note my original post states I tried adjusting the idle jets, I will try that again also.
The "apparent" problem is missing on one or more cylinders randomly. i.e. rough running. Also while running the rpm (as detected by sight and sound) seems to just drop for a second or two once in awhile.
Please keep the ideas coming, I want to get back out on the ocean fishing, missing setting my crab pots.

 

[heyblue]

well gave up and brought to local boat shop. He found my idle timing was way off. Tried it and works fine now. That is the good new, he also said he felt the reeds were leaking and the motor is not worth tearing down for that. So I will use until it won't let me anymore.

 

[jerryjerry05]

Found the "reeds leaking" WTF???
I love reading these new posts where a mechanic will tell a customer something like this.
I don't think I'd go back to this guy.

The "idle jets" are air/ fuel ratio screws. Not idle screws.
The idle is adjusted in a different way.
The screws are set to allow the proper air/fuel ratio at an idle.
Changing these can increase/ decrease the idle but can do serious damage in the long run.

Put the thermostat back in. The motor was designed to run at a certain temp.
It can use excess fuel and case damage in the long run.

The air screws.
Motor warm and in gear.
Turn the screw in until the motor bogs, coughs or stalls.
Then out 1/2 turn.
Do this on all the carbs.
Repeat.

 

[racerone]

??????------------Why would you tell an owner to put a thermostat in that motor ?------------I do not believe that that motor ever had a place for a thermostat !!!!!!

 

[heyblue]

Raceron
You are correct this vintage motor does not have a thermostat, nor is there a place to put one.
Jerry
I am aware that the adjusting screws on carb are not idle screws, though they are sometimes are referred to as such.
Why do you not believe my reeds may not be leaking?

 

[Chris1956]

Stock reed valves are real reliable. If the motor idles reasonably well, it is very likely the reeds are good. Run her on fresh 50::1 mix, with a TCW-III 2cycle oil and change the gear oil 1/year, replace the waterpump impeller regularly and she could run for many more years. The key thing is to use fresh fuel which helps keep the carbs clean. Check the gear oil to make sure no water is leaking into the gearcase.

 

[Bigreddon]

Temp affects your air/fuel mixture quite a bit. When cold, the engine needs more fuel. Using the choke closes up the inlet to the carbs to make it rich. As the engine warms up, less fuel is needed.

When you start it, you didn't mention if the choke was on or off. If the choke is off, and you turn up the idle, on that engine, you are only advancing the ignition to make the engine run faster. You aren't changing the fuel mixture.

Several things need to be correct. One is the ignition timing. That engine relies heavily on ignition timing to control motor speed. More so than you might think. In fact, when the engine is running, the throttle plates that allow more air (and subsuquenrly more fuel drawn in) aren't even opened until AFTER the ignition timing have kicked up the engine speed. First, the ignition is advanced, then the throttles are pushed open by the arm from te distributor, then the carbs take over, and then again at high speed, the timing kicks in again and gives top end speed.

Once your fuel mixtures are correct, there isn't a difference in low speed, high speed or part throttle. That's all handles by the ignition system. Make sure all of your stops, levers, linkages, bushings are not worn, lubed and not sticky. Hope this helps.