1990 evinrude 120 4600rpm WOT enough?

[archcycle]

Re: 1990 evinrude 120 4600rpm WOT enough?

1. Park on a level, paved surface
2. Block car wheels so it can't move
3. Motor vertical
4. Place wood blocks under skeg until only small space
5. Remove upper engine to transom bolts
6. Raise tongue jack on trailer until slight load on skeg blocking
7. Loosen, but DO NOT REMOVE lower engine mounting bolts in slotted part of motor bracket
8. Continue extending tongue jack until hole you want lines up with bolt hole
9. Replace upper bolts
10. Tighten all bolts
11. Retract tongue jack
DONE

Credit to wilde1j for that.

Me and one helper did it in about a half an hour and we weren't in any hurry. It was exactly as easy as it sounds.

 

[archcycle]

Re: 1990 evinrude 120 4600rpm WOT enough?

Well I have more RPM troubles. Yesterday afternoon, around the end of the day, it started to not like idling right after being started. If I move the throttle up some for about 30 seconds it would start idling fine, but otherwise it wouldn't stay running if I just turned the key and did nothing. This morning it was still doing it and I noticed max rpm was 5100.

Got it home and put it on the hose and it fired up and idled fine.

I did a cylinder drop test:
top port: huge effect
bottom port: huge effect
top starboard: a little effect
bottom starboard: no effect

So I did a spark test. It was sparking strong. So I plugged it back in and started it back up and pulled the top port plug, AND the bottom starboard. It stayed running. Plugged the bottom port back in. Unplugged the top starboard and a few moments later it died.

A few weeks ago I replaced a toasted (all 4 are a year old and clean white on the backs. This one cooked black) bottom starboard coil. This one seems to be firing fine.

Is there reason to test the powerpack here? I do have a nice strong spark. Compression is about 130 across the board.

That's here:
http://forums.iboats.com/showthread.php?t=492639&p=3339517#post3339517
from last week

 

[nymack66]

Re: 1990 evinrude 120 4600rpm WOT enough?

The scoring on the cylinder wall shown is not good, You will not see a perfect idle in my honest opinion. The corrosion around the cylinder is not good also you will need to change your head gasket at lease every year just my honest opinion. As for the compression numbers you are posting the previous owner shave the heads to bring these numbers up, you will see nice torque and WOT however idle will suck. Been there done that ...Use at lease a synthetic blend 2 smoke oil ...Remember if the cylinder wall is scored so is the piston ...

 

[archcycle]

Re: 1990 evinrude 120 4600rpm WOT enough?

Right and it doesn't surprise me that it doesn't idle perfectly, but it sure did idle reliably just 2 weeks ago. I wonder if there could be some gunk in my lower starboard carb restricting fuel there because it's so strange that it's sparking hard on that one but the cylinder drop test has no effect. I'm going to go buy a new carb kit for it right now.

Edit: I never did check on the jets but I'm going to verify them at least in this carb this time around.

 

[nymack66]

Re: 1990 evinrude 120 4600rpm WOT enough?

Be sure to check the foam inside the Cowling, its the number one source for clog jets. I recommended Filter/Water Separating to keep your fuel clean, I only had clog jets once and it was loose foam..Needless to say what my Cowling looks like on the inside today
Hey your Cowling shows 90 HP ?

 

[archcycle]

Re: 1990 evinrude 120 4600rpm WOT enough?

Be sure to check the foam inside the Cowling, its the number one source for clog jets. I recommended Filter/Water Separating to keep your fuel clean, I only had clog jets once and it was loose foam..Needless to say what my Cowling looks like on the inside today
Hey your Cowling shows 90 HP ?

The foam looks like its in great shape although I probably wouldn't miss the amount of it that it would take to clog something.. I do run a fuel water separator and replace the element annually.

And yes, yes my cowling does show 90hp! it also shows evinrude

If you read back a few pages you actually helped me identify what it actually was last year. We got pretty close with 1990 evinrude 140. Then the other week I finally had BRP look up the serial number on the plug and its a j140tles.

My best guess here now is that the PO had an Evinrude 140 or 120. He scrubbed all of the models etc off of it and put the 90 decals on to please his coast guard max ratings plaque. Then his powerhead blew and he found a Johnson 140 and dropped it in there. At this point it just didn't matter if it said Johnson 90 on the cowling. How it got from the PO into the hands of the shop that sold it to me as a rebuilt (turns out rebuilt=repainted powerhead) 1993 90hp evinrude with all of this going unnoticed is unclear.

Either that or he just REALLY wanted screw with the next owner??

I can think of a lot of possibilities, most not good. However it happened it's mine now and it's on my boat. And it just about always works so it has more going for it than the one it replaced!

 

[archcycle]

Re: 1990 evinrude 120 4600rpm WOT enough?

Now that I have the J140TLES model number verified from BRP I was finally able to buy the factory service manual and decided to redo some maintenance.Carb kit and jet/bleeders are going to wait for the weekend.

I'm redoing the synchronization and linkage adjustments. Problem on the cam pickup point adjustment-

2. loosen expansion lock ring and turn adjustment knob counterclockwise until internal spring tension is relaxed.

Well,


Look at the depth of the adjustment knob. It is way too deep and is not ever contacting the plunger. I thought it had loosened when I first did the adjustment but it turns out it had just freed up some crud just past fully tight then I re-tightened it. Clearly in hindsight that did nothing.

Wrong adjustment knob?

The plunger going to the base moves freely when I push it in it's not stuck or anything. It's either just too short or the adjustment knob is too deep.

I had the throttle cable off like it said and it was at fully pushed back with the plunger extended as far out as it can possibly go. It's the same with the throttle cable on there of course.

 

[archcycle]

Re: 1990 evinrude 120 4600rpm WOT enough?

Edited out dumb comment

I just took another look at the parts diagram. Am I missing 86 , 88, and 90? From the pics in the last post I have the spark advance rod sticking out by its self, the cap, and the lock ring. Guess so. Another trip to the dealership.

 

[archcycle]

Re: 1990 evinrude 120 4600rpm WOT enough?

Definitely missing those parts. They fit into the cap as one assembly. A repair shop sold me a used adjustment cap with those parts in it for $10. nice. The two dealerships around here were $22 + wait for delivery and any delivery fee they might have charged.

 

[archcycle]

Re: 1990 evinrude 120 4600rpm WOT enough?

Cleaned out the bottom starboard carb and it is idling fine again and passed the dropped cylinder test- noticeable loss when I pulled that plug wire after cleaning it out, it was definitely getting starved. Lots of carb cleaner and compressed air back and forth both directions. Last time I could hear it sparking hard as I pulled the wire away and as I put it back but no RPM changes. No new kit since that one was an OMC kit from last season and it looked great. I didn't have a good driver to remove the high speed jet but I'll check that another time since I don't have to remove the carb to do it.

Oddly the lower idle bleeder orifice/jet looked like it had a different number than the rest of them. The top said 54, and the bottom 39? The 39 was pretty cut off in the stamping so I think it was a 9. The other carbs had it cut off as well but they were clearly 36. From the way the curves went it really isn't likely that the number was a 6 it just didn't match the upper pattern of the 6 on the other 3 carbs.

Can anyone give input on those jet numbers? I'll be getting a better fitting screwdriver to make a HS jet tool soon to check those out too.


edit:
http://www.boats.net/parts/search/BRP/JOHNSON/1990/J140TLESE/CARBURETOR AND LINKAGE/parts.html
that says the idle orifice, lower, should be 41, which none are
and the intermediate orifice, upper, should be 54 for a 140hp, which they all were

I glanced at a few other years and didn't see a 36 or a 39.