Spark Plug Gap Setting 1984 6 hp

[sturgeon_general]

"Engine Specifications:1984 Johnson 6hp Model#J6RCR I've been using L77JC4'S Gapped at.040.Source for information "Outboard Motor Service Manual 10th Edition" by Intertec.I never had a problem starting the motor in the past,1st or 2nd pull.Lately 10 or more pulls kind of embarassing at boat ramp or if you have a guest going with you,its like are we going to make it back?I use to change plugs every 3 to 6 months,but lately they start to foul out in 2 weeks which is quite costly.I use motor almost every day fishing for sturgeon sometimes short distances ,sometimes long distances at wide open throttle for long periods of time(1 hour).I got a new low speed adjustment needle,set it at 1 and a quater turns out from a lightly seated start position.It will sometimes start to run on 1 cylinder then both cylinders,this happens when spark plugs are about 2 weeks old.I replaced ignition coils thinking coils weren't firing spark plugs.I did a compression check but it was a little hard to do trying to hold the tester tight to cylinder and pulling on the starter rope at the same time.I got a reading of 75 pounds on both cylinders.I know you want at least 90 pounds but I figuired it was because I didn't have a air tight fit.So I decided compression was OK. Have replaced pull start rope two times in a month from all the pulls trying to start engine.I left off the plastic cover over the carburator when I replaced the low speed needle so I could acess the carburator it is nothing but a pain in the ass if you want to clean out carb.Problem is not the carburator runs great with new plugs.I read in a another post where a bad themostat will cause spark plugs to foul,I say this because just about the same time I started having all these problems, I noticed I had a leak coming from the thermostat.I tightened the bolts and leak stopped.I didn't remove or take a look at the thermostat figured I fixed the problem.Engine still pumped water and doesn't over heat.So my next question is could it be the plug wires or the power pack or rings ,it seems to be smoking a little bit more lately I've noticed but it could be from me adding oil to gas and small amounts of Seafoam.Maybe she's old and tired and wants to lay down after many years of faithful service,any advice would be greatly appreciated "The Sturgeon General"."

 

[vics]

"recommended plugs are QL77JC4

"recommended plugs are QL77JC4 but they are only the inductively suppressed version of what you are using. Gap now recommended to be 0.030" but it wont make a significant difference but worth a try. Might even make it worse.

Plug fouling seems to be your problem.
I think I'd try the full Seafoam decarb treatment then new plugs.

Easy to remove and test the thermostat if you are worried about it, but it should get hot enough for you to be able to touch the cylinder block or heads but not for longer than a couple of seconds or so.. depending on how sensitive your finger tips are.

Checked that the choke is closing and opening fully?

Using 50:1 fuel mix and a TCW3 oil?

No evidence that it is flooding and therefore running rich due to defective carb float or needle? It'll idle happily indefinitely?

Still using the original plugs in my '84 6hp!

"

 

[joereeves]

"Old post here, but thought I&

"Old post here, but thought I'd put my two cents worth in just in case James (or other members) might still be having this type problem.

In agreement with what Vic had to say (mixture, choke, s/plugs & gap, etc). Compression quoted seems about normal.

That engine shoud fire and start within six (6) six pulls of the manual starter cord.

I would add:

Remove spark plugs, rig a spark tester whereas a gap of 7/16" can be set. The spark should jump this gap with a strong blue lightning like flame... a real SNAP!

If the compression and spark are as they should be, the usual problem is either a misadjusted slow speed needle valve if it exists or a fouled carburetor.

Fouled carburetor = remove, clean, rebuilt it using a complete carburetor kit.

(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)

Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S 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 (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

Note 1: As a final double check setting of the slow speed valve(s), if the engine has more than one carburetor, do not attempt to gradually adjust all of the valves/carburetors at the same time. Do one at a time until you hit the above response (die out or spit back), then go on to the next valve/carburetor. It may be necessary to back out "all" of the slow speed adjustable needle valves 1/8 turn before doing this final adjustment due to the fact that one of the valves might be initially set ever so slightly lean.

Note 2: If the engine should be a three (3) cylinder engine with three (3) carburetors, start the adjustment sequence with the center carburetor.

When you have finished the above adjustment, 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.

Thousands of parts in my remaining stock. Not able to list them all. Let me know what you need and I'll look it up for you. Visit my eBay store at:

http://stores.ebay.com/Evinrude-Johnson-Outboard-Parts-etc?refid=store"