Evinrude 90?s looper Plastic carb/intake manifold warpage? Dirty calibration pockets?

[sutor623]

So, endless issues with this engine. This is my last effort to figure out what is causing my issues, and I am going to be real black and white and see if some of my brethren on here have any good insight/ideas. Otherwise I guess I will just live with it??..
1995 Evinrude 130 V4 90 degree looper E130TXAOR

Here are the issues:
Engine starts right up when pressing the key in to activate the primer solenoid. Hold the key in for 4-5 seconds, she bogs down and shuts off. Normal. Release the key she stutters and shuts off.
Start her up, give her throttle to 1500-2000 rpms, runs, sputters, shutters, cackles. Drop it back down after 10-15 seconds, engine shuts off.
Start her up, giver her throttle to 1500-2000 rpms. Again, sputters and spits, keep it at high throttle for two minutes or so, drop it back down to idle, will idle well. Pop her into gear, a little shuttering, but not too bad, throttle up, real smooth transition to get on plane. She will cruise perfectly without a hiccup. Will run WOT perfectly and sounds great.
Take her off plane, drop to idle, pop into neutral before shut down and engine will surge up to 2000rpms, gurgling and cackling for about 10-12 seconds, then will drop down to a perfect idle. Let it idle, and it will idle for about 3-4 mins until it will shut off. Will start right back up though.
Fish a spot 20-30mins, start engine, same thing as if the engine was ice cold. Back to square one.

Here?s what?s been done:
Keep in mind that this is a freshly broken in powerhead, with 150psi on all 4 cylinders. Last engine had a mild overhead on STBD side, scuffing piston skirts and ruining crankcase compression.
I have been through these carbs twice. One thing that I have neglected in the past (shame on me) is to pull the Welch plugs off the throttle bodies and actually scrub the idle calibration pockets. Last night I pulled the carbs/throttle bodies, pulled the Welch plugs, and ran some welders tip cleaners through the orifices. One of the two holes in the calibration pockets seemed to be clogged up enough to give some resistance when running the proper sized tip cleaner through them, then the cleaner went through much easier. I think this may have been a part of my issue, but I am not confident that it is the whole problem. Sprayed some carb cleaner in there, and will pop in the new Welch plugs when I get them in.

I got all new gaskets for the carbs AGAIN. This time I also bought the metal side plates that go on the carbs. They are part # 22 on the chart. I feel like they may be a little bent or warped. This would mess up the whole equation on these carbs. Is it common for these plates to warp or not seat properly?

Tonight I am going to check all of the surfaces on the minlon plastic carbs for any warpage. If I find some I guess I will try to do the ol? glass and sandpaper trick.

All of my fuel connections are done with the proper plastic OMC grabber clamps. All new fuel hoses, rebuilt VRO (running 50:1 pre-mix) and even tried a whole other VRO casing. Even put in brand new anti-siphon valve and fuel pickup line into my freshly cleaned aluminum tank.

Anything else you guys would do/check at this point? I remember throwing a straightedge on my intake manifold, I do not believe it to be warped. Could that teeny bit of crud restricting the idle calibration pocket really have caused all these issues?

 

[sutor623]

Also, if I was getting air in my fuel line would it cause issues at idle, at WOT, or both?

Something else that is very odd to me, is part numbers 13 and 19 are the idle and intermediate air bleed orifices. BRP site states that they are both size #33. On my engine, part 19 is size #31 and part 13 is size #33. Wrong sized jet maybe? Would the idle or intermediate air bleed orifice typically be larger?

 

[sutor623]

Hmmmm, I have just discovered that part #19 is the intermediate jet bleed. Part #13 is the idle jet bleed. The older 120-140's have the bigger air bleed in the intermediate. My idle air bleed is larger than the intermediate by 2 sizes!!!! I think this is why my poor engine is starving for fuel at idle and start-up. I either mixed them up, or they were wrong from the get-go. I finally feel like I am getting somewhere here!!

I am still puzzled though, as to why BRP calls for #33 in both jets, and I have a #31 in my intermediate.

I think that the #31 in the idle circuit will restrict the air flow a bit more giving me more fuel at idle. I think I will swap them and see what happens.

 

[sutor623]

OK, so I confirmed a few of my suspicions. All of the float bowls were warped, one was worse than the others. I hit them on a piece of granite with 400 grit sandpaper. Now they all feel even and clean. Didnt take much off, just enough to get em to set flat.

The surfaces where the carbs meet the throttle bodies were all a little warped, again one was worse than the rest. Seems like all of the outer corners were warped inward a bit. I guess thats from all the tension from the 4 mounting screws. The rubber gaskets that hold the carbs tight to the manifolds are quite forgiving, so I dont know if they would have caused any of my issues. I cleaned em up anyways. My goal is to have them all set nice and flush after torquing them down.

The thing that has me thinking that I have found my issue follows: Two of the metal side plates (#22) that go on the carbs were warped enough that they rocked when I set them on a flat surface. I think this is because of the poor design of the 4 mounting screws. The far tip that doesn't have a screw seemed to be bent outward a bit. I am thinking this may have caused some air leakage. I have new side plates on the way so I will install those before putting the carbs back together.

If this doesn't solve my issues, at least I can rule all of this out!!!

 

[sutor623]

SUCCESS!!!!!!!!!!

So, I have FINALLY solved my hard starting, idling issues. Whether it was warped carbs, warped side covers or dirty calibration pockets, this thing will start right up and idle perfectly!! Can't believe after all this effort I finally figured it out.

Another variable is that I went ahead and put a new fuel pump in. I had air in my fuel line coming in from the old fuel pump, so this may have added to the mix. Anyways just thought I would finish this thread out for anyone in the future.

 

[David Young]

Happy to hear you got it fixed