Home › Forum › Ask A Member › 1973 6Hp Evinrude Fisherman hard starting cold
- This topic has 75 replies, 9 voices, and was last updated 2 years, 6 months ago by fleetwin.
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December 5, 2020 at 4:19 am #224284
Well, 2.5 turns out is too much for sure, indicating a problem somewhere…. The needle should be pretty “pointy”, surely not blunt. Check the simple stuff first….Sounds like you have the coil air gaps “close enough”. Check the prop pitch, perhaps it has an 8″ pitch prop from a 10hp installed, which might explain its lack of WOT power also….
Try to do a video of the engine running, maybe that will help us pinpoint something….
DDecember 5, 2020 at 5:28 am #224285To answer the question if I have ever seen a bad OMC reed, the answer is yes; but it’s been VERY rare, and mostly on 25/30/35, “later model” engines from the late 70’s and 80’s. The failures I saw were a reed snapped off. This resulted in a cylinder that was totally dead and would blow a considerable amount of fuel mix back out the front of the carb. If I ever had a reed that was whole but was just not sealing properly, I never knew it.
Long live American manufacturing!
December 5, 2020 at 8:48 am #224287when you did th carb did you…inspect and confirm that the side channel feeding the upper low speed chamber was clear… not certain but I think there is a small jet in the upper half of the carb look closely
if so run a VERY fine wire to clean any varnish crud blow it out with carb cleaner and air pressure with the needle out so no junk will enter the drip chamber
also did you inspect the HS nozzle tube and clear any crud from the side hole allowing fuel to better vaporize
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- This reply was modified 4 years ago by crosbyman.
December 5, 2020 at 10:39 am #224293see video
https://www.youtube.com/watch?v=XgY9oZcK4McJoining AOMCI has priviledges 🙂
December 5, 2020 at 7:01 pm #224346Another online “expert”…. The engine wouldn’t have run with that plugged jet, along with being hard starting….
December 5, 2020 at 7:23 pm #224348partionally plugged 🙂 🙂
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December 6, 2020 at 12:15 am #224363I’d heard that Nova modules burn out quickly on outboards, but not that it was heat.
Will be interested to know if they last…I was thinking the dark lower plug sounds like no spark there (ran an 18 once with what looked like an OK coil, but wasn’t). Was very hard to start, had no power.
Healthy ignition will jump a 3/8″ to 1/4″ gap in open air with a blue spark, and an audible sound.
http://www.omc-boats.org
http://www.aerocraft-boats.orgDecember 6, 2020 at 12:56 am #224364Hi Phil,
Iv’e got about 5 hrs on the Nova type modules ( mine are Laser, house brand knock offs from Princess Auto – kind of a Canadian Harbour Freight store) and so far there is no problem. My electronics friends tell me that the burn out problem likely comes from old coils. The same older coils that will / may power point & condenser ignitions reliably, will cause these universal electronic modules to burn out. The explanation was this. Electronic modules watch the current rise as the magnet passes the coil shoes. The micro second that the current shows a drop, the modules interpret this as peak current and fire the spark. Modules like to see a rapid current spike cleanly without harmonics or fluctuations to the preset point when the spark will fire. Old coils which are beginning to breakdown internally produce a ripply current spike which points & condensers can tolerate well but electronics don’t like. With brand new modern coils the current spike is clean & rapid and the electronics work well. Both my coils had been replaced with new and had almost no hours on them. So far so good. Spark is hot, blue at about 3/8″ with a good pull on the starter rope. Now, if a coil is breaking down at higher RPM and causing a high speed miss – I’ll have to do a wire off test with the motor on the boat, to see if RPM drop is equal on each cylinder. Lakes are freezing here so that’s for next spring.December 7, 2020 at 7:11 am #224473One of the issues here is that we don’t know how the engine ran before you got it, or why the camp ground decided to get rid of it…Perhaps they didn’t tell you something….
I like your explanation about the module failures, makes sense to even this feeble brain.
Can you run the engine in a bucket or test tank instead of lake testing? I’m sure you want to get this thing sorted out before next season. Pulling the plug wires while running can be done in a tank at mid-speeds. Just seems like this thing is running on just one cylinder, especially considering the fouled lower plug. Don’t forget to try new plugs! Just cuz the plugs are new, doesn’t mean they are any good…
Have you pulled the carburetor core plug yet, you can do this without removing the carb to see it the metering holes are clear and to check for a damaged low speed needle.
You mentioned reeds in your last post, which is possible. While you rarely see broken reeds on these engines, but there surely could be some crud caught under one of the reed pedals. The problem here is that you must remove that pesky rewind to get the intake manifold off. So, I would hold off on pulling the manifold until you have ruled out simpler stuff….
Most of our issues are usually simple ones, until we skip over the basics…
I am experiencing somewhat similar symptoms on a 6hp that I just rejuvinated, maybe we will help each other out figuring this out….DDecember 7, 2020 at 11:53 pm #224587Good evening all,
Well, the results are in. I pulled the carb again and went through it with attention to all the info provided by Crosbyman, Fleetwin and others. I did not find any dirt but I blew out all passages and under the welsh plug too. The LS needle is still a bit blunt but I cleaned it up with some very fine emery cloth. There is no broken point in the LS orfice. It now cold starts reliably on the third pull with choke on and throttle at 3/4. Warm starts reliably on one pull with no choke and throttle at 3/4. Trolls about the same. BarreI test shows it still runs best with the LS needle at 2.5 turns out. Wire off tests at 1/2 throttle show equal RPM drop for each cylinder ( I forgot how much that stray current hurts!). Overall performance is acceptable and I think this will be all I do on this one> If the hard cold start condition returns I will likely jury rig a primer. I did this on my 1970’s snowmobile engines and they were never more than a 2 pull start even in the coldest weather after the retrofit. I’m pleased with the performance of the electronic ignition modules. An unanticipated benefit of having them mounted on a heatsink off the block is that you can carry an extra one in your tackle box and change one on the lake with nothing more than a screwdriver if one should fail. Can’t do that if it’s under the flywheel. I attached a better picture of the assembly if anyone cares. I hope to keep you posted as to their ultimate success or failure sometime next summer. Onto my next project – a 1951 Neptune Mighty Mite 1.5 hp built by Muncie Gear Works, Muncie Indiana. My long gone dad loved his and literally wore it out. Many Thanks to all who commented Esp. Crosbyman for teaching me to “chase one rabbit at a time”- This reply was modified 3 years, 12 months ago by Mumbles.
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