1977 Johnson 85 horse runs good on 3 not 4

[MRneatfreak]

Re: 1977 Johnson 85 horse runs good on 3 not 4

:facepalm: :facepalm:

Well I couldn't even leave the dock. This time the only way I could get it stay running was to bump the choke with the key, or hold it mostly closed on the engine. I didn't take into account the hole in the butterfly for the idle. Too much air right? Causing a lean condition? I tried to get in gear but it would just chug out unless I could feather the choke mostly closed on the engine. So I guess I need to fix my other carbs that had the smaller diameter jets in them or move the butterfly's over, probably easier just to re-jet, and R&R the carbs. The carbs that came on the motor originally had this casting in the front of the carbs 322033. Any ideas where I could at least get one welch plug (the one I ruined when I drilled and removed it), or maybe a new kit?

 

[emdsapmgr]

Re: 1977 Johnson 85 horse runs good on 3 not 4

Any chance that someone has changed the carbs on that engine? Almost sounds like someone may have put 115 carbs on your 85. That can work, but if you then change the jets in the 115 carbs back to the 85 jets, you will be going backwards. You'll be getting more air/less fuel. Perhaps you can check/verify the throat size of the carbs. There is a measurement cast onto the front flange of all V4 crossflow carbs. On an 85 the carbs they may have a "1" cast onto that front flange. That is the throat size of the carbs. For instance on an 85 engine, the factory may have put "1" carbs on the engine and those would have had .045 main jets according to the factory parts list for that year. A 115 might have had 1 3/16" carb throats, and .059 main jets. Basically, you need to match the carb jettting with the throat size of the carb body in order to flow the correct air/fuel mixture. Keep in mind that your 85 block is different from the 115/140. Your block has less displacement, at 92 cubic inches. The 115/140 blocks are 99.6 cubic inches. That makes a difference when doing carb work.

 

[MRneatfreak]

Re: 1977 Johnson 85 horse runs good on 3 not 4

Any chance that someone has changed the carbs on that engine?

Anything is possible with this boat. Those carb numbers don't match up with what Evinrude said they put on there for that year. I didn't get to hear what the previous owner did with it. I bought it from a guy who was just looking to flip it (make a profit, w/o doing much of anything to it) and he couldn't (or wouldn't I don't know) tell me much about it. All I knew is it had great compression, and a different colored lower foot. I have found many things about the whole boat/motor/trailer project that have been unsettling as far as repairs by the previous mechanic. So anything is possible. I got the whole combo for $500. I thought if worse came to worse I could probably get that out of the trailer and parting the motor out. I was hoping I could get by w/o removing the carbs again, but I guess not.

 

[MRneatfreak]

Re: 1977 Johnson 85 horse runs good on 3 not 4

Ok had my boy help me remove the carbs for a closer examination. Took off the choke plate, low and behold those carbs that I took off my other donor engine are a 1 5/16. So they are for a 135 horse Johnson. I currently have the .25 and .49 jets in them and would explain why I couldn't get anything to fire that last time I took it to the ramp. Too much air not enough fuel. So I'll have to scrounge around the garage for 2 one inch bore carbs, and make sure they have the .25 and .49 jets in the them.

 

[MRneatfreak]

Re: 1977 Johnson 85 horse runs good on 3 not 4

Took the boat out for a spin tonight after getting the right carbs on there: two 1" carbs with .025 and .049 jets. I ended up replacing the floats, pintle's and seats and in general cleaned, blew out etc all of the orifices, threw new gaskets on for the bowls, and to the engine. Has all new fuel lines. New evinrude primer bulb although it is a 5/16" not 3/8". Engine starts and idles beautifully, slides into gear great. Is quick to get out of the hole and about 4 seconds later lose all power, have to throttle back for a couple seconds then can again go full power for about 4 seconds, before it starts to die out. I tried bumping the choke, and it doesn't do anything for the engine, it just continues to die. I played around with the high speed screws turning all four in 1/2 turn increments. This just lowered my out of the hole time by gradually slowing it down. Turned em all back in tight and it again is quick out of the hole to full power, but only for a little bit. I checked the primer bulb after it dies down after full throttle and it is fairly hard. I'm using an older portable 15 gallon Moeller tank with an internal fuel guage, it has crossed my mind that it may be plugged partially. It also will run continuously at about 85% power.

What is next on the agenda? Fuel pump? Should I try a 3/8" primer bulb?

 

[MRneatfreak]

Re: 1977 Johnson 85 horse runs good on 3 not 4

Bought a new fuel pump, and this solved all of my previous problems. A new one cropped up last night. It was dark and I was in the bay doing sea trials, and kept hearing a rough idle and an intermittent snap. Took the cowling and saw the spark jumping out between the sparkplug boot and the sparkplug itself on #4. The boot was on all the way? It sometimes helps to press with all my might but soon its back to sparking again. It doesn't seem to do it at WOT, unless it is just too hard to distinguish? I couldn't see any cracks in the porcelain, but decided to replace it anyway. Which leads me to this question.

What is the difference between these two plugs QL77JC4 and L77JC4? The QL's came with the engine, I removed them because I thought they were fouled when I first started this story 3 months ago. The dealer sold me the L77JC4'S? And one of the L77JC4's was what was arcing. Not having a spare L77JC4 I removed all the dealer plugs and reinstalled the QL77JC4's and gapped to .030"

The only real difference I could see between those two sets, was that the QL77JC4's were about 1mm shorter in length from the electrode to the base of the plug threads.

BTW, this engine screams

 

[MRneatfreak]

Re: 1977 Johnson 85 horse runs good on 3 not 4

Found this, apparently the only difference is the Q plugs have a resistor designed for use with CDI electronics.

http://www.sparkplugs.co.uk/pages/technical/champion-code.htm

 

[emdsapmgr]

Re: 1977 Johnson 85 horse runs good on 3 not 4

You've made a lot of progress with your engine. I'm concerned about your comment regarding the fuel hose bulb. You should pump the bulb till it's hard prior to starting the engine when it is cold. Once the engine starts and runs, the engine will begin to draw fuel through the hose. The bulb will normally get softer as the engine continues to run. The bulb should get softer-but should not collapse. That's normal. What's not normal is for the bulb to stay hard while it contiues to run. You may have a problem with the ball valves in that hose bulb-restricting fuel flow. 5/16" fuel line should be just fine for that engine. 3/8" will also work on your engine, but is required for the 140 crossflow and V6 engines. It's normal for your engine to die if it is choked once it is warmed up. Is your fuel tank vented? A weak fuel pump is possible. If the engine runs, but is not sustainable at WOT, the pump could be weak. Will supply some fuel, but not enough to run sustained WOT. I'd address these other issues before you opt for a new fuel pump at this point.

 

[MRneatfreak]

Re: 1977 Johnson 85 horse runs good on 3 not 4

Ok the fuel bulb logic make sense now. I guess I thought that if there was fuel pressure the bulb needed to be hard, not so. I replaced the fuel pump yesterday, and it solved all my bogging issues at WOT. With the new pump came a softer operating fuel bulb. Gonna see if the QL spark plugs make a difference in the water today as far as that arcing problem is concerned.

 

[MRneatfreak]

Re: 1977 Johnson 85 horse runs good on 3 not 4

After reverting to the QL plugs I didn't have any more idleing or spark problems, although it took longer than normal to get it started when cold.

 

[MRneatfreak]

Re: 1977 Johnson 85 horse runs good on 3 not 4

After rereading the stickies I wonder if I misinterpreted the meanings for carb adjusting w/ needle valves?

http://forums.iboats.com/showthread.php?t=167352

When it says turn out the needle valves, is it talking about the brass screws that cover the hole to the needle valve?
Or is it talking about physically turning out the needles themselves inside with the special tool?

It reared its ugly head again, engine started to stumble harder than normal after running wot in 1-2ft swells and a heavy load of passengers and tackle. Sometimes after power down it would be ok, put if I tried to power up it sounded like it was running on 2 cyls. It was dark so didn't mess with it. Primary objective was to get back.

Another question on ignition. Put on new ignition coils, that came with universal length leads. I found that #4 was shorting to the block (at night) rather than going to the plug. Was wondering if I should trim up the lead to just as far as it needs to go with no slack. Path of least resistance?

 

[emdsapmgr]

Re: 1977 Johnson 85 horse runs good on 3 not 4

Normally the engine will work just fine with standard length coil wires. When that engine was first made, it had insulated holders for the spark plug wires. These metal holders with rubber coatings kept the wires from touching (grounding on) the block or the lower cowl latches. Or from snagging the upper cowl when it was put back on. For instance on your engine, the holders would have been a number of 310928 or 313774 retainer clamps.

 

[MRneatfreak]

Re: 1977 Johnson 85 horse runs good on 3 not 4

Found a broken spark plug lead retainer on #1. The part that snaps over the plug head. The engine still has 4 of those holders but they are still way too long even using those retainers. I also found #2 and #4 coils were touching where the leads come out of the coil, so had to move the coils around, but didn't disturb which cylinders they send fire to. Zip ties are your friend. Didn't find any arcing? Maybe its still a carb issue. More sea trials.

I'll have to get some video one of these times.

 

[MRneatfreak]

Re: 1977 Johnson 85 horse runs good on 3 not 4

Well here is a short video of my motor finally performing well. I'm running a 21P SS 3 blade prop. I gave 100% throttle and it took a bit to get up to speed. I also don't have tilt/trim, and have it locked at the second hole from full down. Thanks for all the help!

http://youtu.be/vnJcnB4bfGU