At My Wits End!!!

[nymack66]

Re: At My Wits End!!!

Post a brief history of this engine. Example , are you the original owner, Engine ran perfectly up until ?
Parts replaced by whom ?
History of your fuel pump? VRO connected or not?
Double check the Stator/Trigger plug any bent pins?
Connect in line spark tester check for constant spark whilst engine running they cost under 5 bucks each and you need to own em comes in handy many times over!
Basically if your engine can't even start and run at idle forget the rest of the troubleshooting like WOT timing fix this first.
Are you absolutely sure this is a 1988 120 like you posted? Post pictures of the engine if you can..
Plugs post brand and gap?
Move all power pack wires to coil away from coil to plug wires etc..
The more you provide the easier it is to fix . AIR/GAS and Correct fire any Looper will at lease idle

 

[ezeke]

Re: At My Wits End!!!

Check your wires from your power pack to your coils, Standing on the ground with the engine in front of you port =left starboard=right
Verify each wire from pak to coils ..
Cyl=2 Red&Purple Cyl=1 Blue & Red
Cyl=4 Red&Orange Cyl=4 Green &Red
Also unplug the connectors from the trigger and stator, look at each pin verify none is bent or off to the side, lube with an electrical lubricant re-connect and test ..

Just so we are on the same page, the 1988 120 powerpack has QuikStart and S.L.O.W., and,

The wires to the ignition coils are:

Cylinder 1 = blue and orange
Cylinder 2 = purple and orange
Cylinder 3 = green and orange
Cylinder 4 = red and orange

QuikStart should engage for 5 seconds every time the engine is started, warm or not.

QuikStart should disengage when the engine reaches 96 degrees F. or 1100 RPM, whichever occurs first.

This engine should be allowed to warm up before reaching 1100 RPM or QuikStart will disengage prematurely, causing a rough idle.

 

[ezeke]

Re: At My Wits End!!!

Also, some 1988 120 and 140 models had a faulty installation of the port temperature switch which caused S.L.O.W. to activate and/or caused erratic operation of QuikStart. [Service Bulletin #2197].

You may temporarily disconnect the tan wire leading to the powerpack in order to troubleshoot.

 

[minkota]

Re: At My Wits End!!!

sorry for the delay in responding, we had a death in the family and had to attend to the estate, but I am tryinh to get back on this now.

This engine should be allowed to warm up before reaching 1100 RPM or QuikStart will disengage prematurely, causing a rough idle.

It does this (when it does start) but it goes well over 1100 rpms when it first starts, i think it is more like +1500.

Also, some 1988 120 and 140 models had a faulty installation of the port temperature switch which caused S.L.O.W. to activate and/or caused erratic operation of QuikStart. [Service Bulletin #2197].

You may temporarily disconnect the tan wire leading to the powerpack in order to troubleshoot.

I have tried that and there was no change...

Thanks

 

[191Seanymphstriper]

Re: At My Wits End!!!

Hello All, New Here and have a problem.

I have a 1988 120hp Johnson and it runs very rough (when it does run).

Things I have tried:


1) Rebuilt Carbs
2) Changed Fuel Lines
3) Changed Power Pack
4) Changed Coils
5) Chnged Stator
6) Changed Timer Base
7) Checked Compression (100+ on all Cylinders)
8) Chnged head Gasket Just because I had an extra Set
9) Connected an External Fuel Tank to Eliminate on Board Fuel System as a Problem.
10) Check Reeds, all appeared to be ok and functioning properly. I did not remove them I only looked at them when I had the carbs off

I am not a marine mechanic by any streach of the imagination, but I am a retired auto mechanic so I am familiar with motors. with that said I have exhausted every thing I know to check or replace on this motor, what else can cause a rough running motor or keep it from starting.

I have searched the forums but have not found any threads with similar symptoms. I just dont know what else to look at...Thanks in advance for any help.

You diddnt state that you changed the plugs or the wires going from the coils to the plugs. Do that. Even a little carbon build up on a plug can throw this off or fluded plugs. also the wires. You may have a bad wire or green build up on a wire shorting out!

 

[191Seanymphstriper]

Re: At My Wits End!!!

Also even if you did buy all new coils it dosent meant the coils are good. Test each coil.

 

[191Seanymphstriper]

Re: At My Wits End!!!

Get a spark plug inline light spark tester etc and try from the coil to the wire then plug first then try from the plug to the wire with the wire then going direct to the coil. There may be a bad new coil or a bad wire... or a fauled plug!

 

[ezeke]

Re: At My Wits End!!!

It's significant that the engine goes above 1100 RPM at startup, because it should not unless you are using the warmup lever, which is not often needed with QuikStart. If the throttle plates are properly synchronized, they should all be fully closed at startup or idle, so you might want to check that.

The sequence for Synchronization and Linkage Adjustment begins on page 1-39 of your factory service manual and is a step-by-step procedure which should be done in the order presented.

If you are not completely comfortable with the timing adjustment, it would be to your great advantage to take the rig to a shop that has the proper equipment and training for that step in the process.

 

[191Seanymphstriper]

Re: At My Wits End!!!

Ok listen. Put the boat in the water on your trailer with all trailer tie downs still locked down at the transom and bow of the trailer locked. Back her into the water so the motor when tilted down is fully submerged and able to pump water. Or if you keep it docked just tie up real good. Make sure your parking break on the truck is on good! But in reverse the thrust is less so you wont have a issue!


Start the boat. Rev it up and get her in reverse at 1700 rpm. With your air breather off of all the carbs close each butterfly one by one with your hand by sticking your finger in the carb and close each one and see if it bogs down on each cyl while the boat is under load at 1700 rpm in reverse.


They each should bog down the motor!


If you close one butterfly and dont here a bog or takes longer then others to get boged thenn that cyl is either getting to much fuel so the cyl is flooded or barly sparking and working less causing your ruff idle.


Now this can mean a couple of things. If the fuel pump is conected to the cyl that takes longer to bog its the fuel pump. because whats happening is the diafram in the fuel pump is warn punctered etc.

And what will happen is that cyl will draw alot of fuel flooding it causing the ruff idle and low spark bc of the flooded plugs.

Just because the fuel pump is shot does not mean that the other cyl arent getting fuel and wont get fuel.


It just means 1 cyl is getting to much fuel....


Or that cyl that takes longer to bog or dosent bog at all may have a bad plug or failed plug, or a bad coil, or a bad wire that goes from the coil to the plug.


Now these are the quickest easyiest ways to fix and try to solve the issue. Do these techmecs before you start ripping the carbs off...


""""(Also when the fuel pump is removed from the engine, start the engine with all hoses disconnected etc just as you disconnected it. And give some throttle and let it come down in idle and put in nuetral. Now if it is the pump she should idle in nuetral because now the 1 cyl is not getting extra fuel and the fuel left in the carbs will even out and should idle for about 2 min to 5 min,,,,,)""""""

"""""(Now if she dosent idle without the pump in then its not the pump!)""""


Now if you change the difram in the fuel pump and you change the coil, plug, wire and you still have a issue with that cyl then take all the wires off the plugs and do a complete comp test and be sure you have good even comp. Anything within 15 psi of each other is still considered good.

So if its 115 120 110 105 its still good but will give you a little uneven ness but not enough to sound like a uneven idle or be an unevian idle.


So if you check compression and its all good..... Then take that carb yjay bogged slowly or not at all off and rebuild it and put it back on.... Then it should be fixed..... You may find debri etc or signs that moisture may have bean in it etc.

Let the carb soak excluding the float in (SEA FOAM) (a product to clean fuel systems) for about 3 hours as long as all plastic pieces are off yje carb. Then rebuild the carb!


Those are the only things that can cause the un even idle....

You now at this point after doing this have checked and repaired spark,fuel,air, carb all the things you need to make her run... If you don't know how it works you wont be able to fix it!


Unless your stater is no good which if it is that would be most unlikly and it wouldnt even start at all. Or a elec short which is all uncommon


Follow these steps and trust me youll find the issue...


Dont start drilling your carb etc etc ...... Just not a good idea with debri shavings etc..could cause more problems.. ( No offence to Daviet at all) (I Just wouldnt do it at all personally!)


Get a very small hook pick and a small strait pick and get it out... And again No offence to daviets advice at all but I just wouldnt do that personally! Daviet may be a very experienced mechanic for all we know and he may have a very steady hand!

You can do whatever or however you would like to get it out! But just be carfull if your drilling


And tell me what happens...


Also your phone number was edited out and you cant post your number directly on the thread. You can click on my screen name and send me a P.M (personal Message) with your number and i willl walk u threw it again!


Hope my advice and daviets advice helped!

 

[nymack66]

Re: At My Wits End!!!

All good ideas posted any updates ? You also mentioned new Stator and Trigger which obviously meant you pull the flywheel. Please verify its not spun on the key since the re-install! Any Outboard repaired to this extent you mentioned at lease will start and idle.
Keep us posted ...

 

[191Seanymphstriper]

Re: At My Wits End!!!

? Anything?

 

[minkota]

Re: At My Wits End!!!

You diddnt state that you changed the plugs or the wires going from the coils to the plugs. Do that. Even a little carbon build up on a plug can throw this off or fluded plugs. also the wires. You may have a bad wire or green build up on a wire shorting out!

Plugs are brand new, coils/wires have been swapped from a known good running engine, with no change. I feel it is a fuel issue as all the electronics have been changed/replaced with no change in performance. I just do not know what to look at I have rebuilt the carbs several times, inspected the reeds (visually). any other ideas would be greatly appreciated.

Also, the tests you want me to do, require the motor to run ( it will not run for more than a few seconds (5 at most)).

If anyone lives near the Palm Beach area, I would love to get a second opinion, maybe I am missing something simple and obvious.

Sorry for the delay in responding, I am still dealing with estate issues as well. Thanks again everyone.

 

[minkota]

Re: At My Wits End!!!

???

 

[mrcj001]

Re: At My Wits End!!!

Let me give it a whirl..........

With all the new parts installed and installed correctly and the compression is good and even and you you have good strong spark on all cylinders, this engine should start and run.

But, If it is not linc & sync properly you will have the conditions you are having.

Try this:

Disconnect the throttle control cable at the engine end.

See if you can adjust the idle stop screw either back or forward to see if you can get the engine to start. If it does and is at a real high idle, with the cable still disconnected, adjust the idle stop screw to it will run/idle.

If you can get it to run, shut down the motor and adjust the throttle cable so it will connect to the lever without moving it. You will need to adjust the trunnion wheel to make it longer or shorter.( Fit the cable to the motor, not the motor to the cable.)

Then, loosen the carburators throttle adjustment screws, stick your fingers it the carbs and make sure that all are closed and tighten the adjustment screws.

The engine should run, unless the timerbase is way out of time. Then you will need to verfy TDC on the #1 piston. If it doesnt line up, you will need to adjust the timing pointer and adjust WOT.

Then if all else fails, Pay a outboard mechanic and see if they can fix it.

 

[Rscardina]

Re: At My Wits End!!!

I'm in complete agreement on this one.. I had similar issues, just ask JonesG about it.. we spent hours tracing and diagnosing.. eveything I noticed seemed to point to fuel.
after long hours and weeks spent chasing ghosts..I got fed up and took it to a shop... in the end...I did evrything correctly EXCEPT..my timing was way off..

Like you, i thought I had timing all set...

after timing got adjusted in a test tank..and ramped up to all rpms and in between...i have a great strong working engine...

just saying that if all else is spot on.. make sure the timing is as well...it just might be off a bit to create the issues you are having..

 

[Gary_in_Tn]

Re: At My Wits End!!!

For what it's worth, I haven't seen anyone mention a vacuum leak. I've had cars act the same way with a leak in the intake manifold. Don't know if this translates to outboards or not ...

 

[nymack66]

Re: At My Wits End!!!

This engine year and model is some of the simplest outboards known to man so dont worry it will be resolved. Unplug the harness connectors you have from Trigger and Stator two things to look for bent pins or pins pushed in not connecting..If all looks good lube with a recommended eletrical grease and re-connect.
Do yourself a huge favor and go to http://www.harborfreight.com/inline-ignition-spark-checker-4424.html and buy four.
Connect one to each cylinder, verify all your butterflies is close, Crank her with the Cowling off and verify the firing, observe for consistency and order of fire verify the order in your manual. Post your results and you on your way to resolve this.
Note most loopers like to start with the butterflies slightly open...We address the rest later , lets first get her to start and idle..This motor has no magnets to loose or twist off its cast into the flywheel as shown.
Please verify the throttle arm is NOT pushing the timing advance (blue) back because of a broken spring in the advance arm it should be something close to this as shown.
Post pictures if you can ...

 

[ezeke]

Re: At My Wits End!!!

More big bore loopers have been destroyed by incompetent timing adjustment than you can count.

Get someone with the knowledge and equipment to do it correctly so you don't turn your motor into a 65 cent/pound scrap metal.

 

[minkota]

Re: At My Wits End!!!

Sorry, I just realized I never posted the resolution. Once I got the Link & Sync done correctly the motor ran and idled but still had a miss. I then replaced all the fuel lines and in doing so noticed some trash falling out of the fuel pump, after spending a while trying to clean the pump I decided to just replace it. now motor runs like a champ! took the boat out for sea trial and it went over 45mph(gps) with no trouble. Thanks again to everyone for all your help.

 

[mamm7215]

Re: At My Wits End!!!

Thanks for the reply!