1994 E120TLERC air mixture adjustment

[jimbobcooter]

I just rebuilt 2 of the 4 carbs on my 1994 E120TLERC (other 2 on deck). I pulled the air mixture screws during the cleaning. I noticed one was about 2 & 1/2 turns of seat and the other was maybe a 1/4 of a turn off.

Is there a good starting point to back them off? or should I return to what they were prior to cleaning?
I read in the manual that I have to get the engine warm and then make minor adjustments on each until I find a good idle with no coughing/spitting. I want to make the post winterization startup and tuning as smooth as possible.

Thanks,
Joe

 

[wrench 3]

According to my book the initial setting should be, backed out 2 1/2 turns.

 

[Faztbullet]

Those are adjustable intermediate screws and should be set 1-3/4 off light seat to start. It was a engineers thought that making this adjust would solve bog problems when whole problem was intake and recirculation problems...These HAVE to be adjusted in water,off trailer, in gear,trimmed down to get it adjusted where it wont bog(lean) coming up on plane...

 

[wrench 3]

If you go to http://boatinfo.no/lib/evinrude/manuals/1992-2001johnsonevinrude.html#/120, the base setting specs are on page 186 and the in water adjustment procedure is on page 120.

 

[Faztbullet]

That Seloc manual does not show how to adjust the intermediate needles if equipped ....

 

[jimbobcooter]

Update: I started her for the first time today after winterizing and carb rebuild. She fired right up no problems and blew a ton of smoke. However, she is definitely not running on all cylinders and has a noticeable misfire. After a few min on the muffs I shut her down and pulled the plugs to find a few of them black. Thinking that the fogging oil might have fouled them I cleaned them off with some gas and tried again. More or less the same story. I am wondering if I just need to adjust/tune the mixture screws per the manual or if I have a leak somewhere. Currently all mixture screws set per manual so I am sure they need to be adjusted some anyways but I need some advice in case I have another issue I will never get them adjusted properly.

A few observations:
3 of the 4 plugs are black and one is a nice tan color (see pic) http://i67.tinypic.com/2irjh2.jpg

I noticed that there is a small amount (almost a drip) of fuel/oil on the bottom of the posts with springs on them--not sure what they are but I am pretty sure they are attached to the throttle body...no puddles of gas or anything in the bottom of cover----could this be a leak from one or more of the carbs? or just a really rich mixture? (see pic drip wiped off but part I am talking about is left of the carb bowl) http://i64.tinypic.com/294qeyq.jpg

Adjusting the schrader valve had a noticeable impact on the motor. It seemed to run best in the position pitcured. If turned pointing straight away from the engine it would stall...if pointed straight at the engine the rpms would increase and it seemed to run better but still missed. Where should this valve be placed when operating? when fogging? (pic http://i68.tinypic.com/2zyfv6b.jpg)

Any and all advice is greatly appreciated

Joe

 

[racerone]

That red lever manually opens the primer valve.----Lets fuel in that bypasses the carburetors.------The shreader valve is only for injecting fogging oil / engine tuners.------The red lever should be positioned so that primer valve is closed during engine operation.------Usually that is in line with valve body.

 

[jimbobcooter]

So inline with the valve body? Would that be straight towards the engine? Straight away? or towards the front of the boat? I am thinking [FONT=&quot]counterclockwise "manual on", clockwise till stop is "run" position.[/FONT]

What about the small amount of oil/gas mixture?

Could out of tune carbs cause it to miss? foul plugs? Should I try to tune carbs or do you think I have some other issue?

Thanks for the help!

 

[jimbobcooter]

Finally got around to working on her again. Placed the schrader valve facing directly towards the engine.

Checked spark and compression both checked good. Sprayed some carb cleaner around all the of the carb to fuel rail connections and at the carb attachment interface. I noticed a slight improvement around one or two of the fuel line connections.

I then removed all the carbs and cleaned the double br*** tubes with a small piece of copper wire. Replaced all fuel line zip ties with metal gasket clamps tightened just enough that there are no gaps b/w the gasket and hose.
Reattached and noticed maybe the slightest of improvements. I noticed that the initial bulb prime did not result in any leaks at the bottom of the throttle butterfly shaft return spring. However after running for a short time there was moisture present at the bottom of both (not dripping but when touched there is a drop).

The engine starts and will idle with a very obvious miss. I am thinking at least 2 cylinders. At slightly higher rpm seems to run fine.

When I was cleaning the carbs I noted how many turns each carb mixture screw was out. Upon re***embly I returned them to stock spec (I believe 2.5 turns out). Could this be severely off mixture adjustments?

Any other suggestions? Could I have mixed up the attachment order of the fuel lines to the fuel rail?

I was thinking one last attempt to return mixture screws to original settings (pre cleaning) and try to run one more time will all new plugs. Thoughts?

Post run pics of plugs:
Image - TinyPic - Free Image Hosting, Photo Sharing & Video Hosting starboard side top plug moist somewhat black bottom plug dry and black
Image - TinyPic - Free Image Hosting, Photo Sharing & Video Hosting port side top plug slightly moist and black bottom plug dry and black
Image - TinyPic - Free Image Hosting, Photo Sharing & Video Hosting fuel line orientation on fuel rail.

Thanks again for all the help!
Joe

 

[jimbobcooter]

Had a mechanic come out and he found the port lower cab to be the issue. Seems the air mixture screw was seated to far and likely destroyed the brass seat inside the plastic carb. My spark and compression were both great. He got the engine idling smooth by turning the air mixture screw all the way in an then adjusting the others & idle speed until it idled right. He said it was running real rich...so much so that he was surprised the engine would even run. Lake test tomorrow.

Hope no one else has the same issue but if you do I hope this helps.