Post rebuild questions

[hoeser]

Hi Guys,

I'm still in the process of breaking in my 84' Evinrude 140 that I rebuilt. It is running very well and is on around hour 4 of the break-in. I have two questions;

1) Do I need double oil for the entire 10 hour process?

2) Should I decarb after the first 10 hours? Seems like a lot of carbon could build up during this time with double oil.

My plugs are quite black after the last inspection, I suppose this is to be expected with this much oil.

 

[reeldutch]

Re: Post rebuild questions

i'm about done with the break in of my 1988 v4 looper 140.

i checke4d the plugs constandly and they did not seem to get to dirty.
the porselin insulator should be a coffee color with milk. Tannish.
did you check the temp you dont want to run it to cold. that will cause carbon buildup.
should idle around 145 give or take 5*
i personaly prefer ql77jc4 for plugs. gapped .035
and im using yamalube 2m witch is a synthetic blend of tcwIII.
are u mixing 25:1 ?

i use 87 octane .

i dont think it can hurt to do a decarb but after only 10hrs i dont think you need it unles something is causing exesive carbon buildup.

-cold temp
-floats to high (rich mixture)
-wrong sparkplug
-oil mixture to high (VRO)

 

[hoeser]

Re: Post rebuild questions

After pulling the plugs I would say the insulator is more of a coffee color with less milk than desired. Heh. It's not "Black" but its not "Tan" either, I'm a guy so I would call it "brown" but I'm sure it has another word.

I am using TCW-III but it is not synthetic.

To be honest I never temp gunned it but I would suspect it is in that temperature range. The heads are very warm to the touch but you can still hold your hand on it which to me suggests around 140 degrees Fahrenheit.

My plugs are L77JC4's gapped to .040.

I'm mixing 50:1 in the tank, VRO is taking care of the rest.

Mixture seems O.K, after an "extended" period of idling... like say, 2 or 3 minutes, if I drop the hammer it shudders a bit while transitioning but gets to balls out speed pretty quick. If I drop it off that same plane, back to idle, then hammer it again after only a brief period at idle, it picks up with no shudder. I am assuming it's the double oil.

 

[reeldutch]

Re: Post rebuild questions

if you say you can hold your hand on it for how long do you mean?
if you can hold your hand on it longer than about 3 seconds you are running cold.

if you can hold your hand on it as long as you want you are defenatly running cold and explains the extra carbon buildup.

check the temp.
cold running is asking for your rings to buildup with carbon.

reeldutch

 

[hoeser]

Re: Post rebuild questions

To be honest I could probably put my fingers on the head all day without a problem... so I'll get out the temp gun tonight and verify. It doesn't *seem* that cold to me.

If it is cold, I'm going to assume this is the thermostat. If I put a new one in, how easy it is to change with the powerhead on?

 

[reeldutch]

Re: Post rebuild questions

if you have a bubble back crosflow than it is a pain inn the a** to do it with the ph on. you can do it its just a pain.
theres a few threads that can help you out.
i have done it before but now i would pull the ph.


yep thats way to cold.
you will idle a lot smoother when the engine is at the right temp.
you will be amazed.
also you will burn a lot cleaner deu to combustion temps. more complete burn.
fuel atomizes better so overall it will run better.

a good indicator is if you can hold your fingers on top of the cylinderhead for 3 seconds you will be about right.
if you can leave your fingers on it all day long chances are your tstats are stuck open.

the best way to check the temp is put your boat in the water and let it idle a few minutes check for the temp with the gun.
it should be around 145 ideal.
135 acceptable 155 and over to warm.

reeldutch

 

[hoeser]

Re: Post rebuild questions

Well I actually boated in to work today so I took her out at lunch. I left her idling for 2 or 3 minutes at the dock when I got there then pulled the cowl and put my fingers on it. To be honest it gets hotter at idle than it does after a WOT run. I couldn't really hold my fingers on it very long at idle, after barreling down the river at wot and then pulling the cover, it was cooler. Touchable but still warm. I will get the gun on it later though.

 

[hoeser]

Re: Post rebuild questions

Oh and yeah... it's a bubble back crossflow... I'll do whatever it takes to get it done without pulling the powerhead again.

 

[reeldutch]

Re: Post rebuild questions

its normal to be cooler after a wot run because the presure pushes the presure releve valves open and dumps as much water out of the moter as the impeller can put in.
thats ok.
intermidiate and idle it should be hot to the touch.145 F
at this stage the tstats handle the amount of water flow threu the engine.

i know how it is ive been there.
just to make you feel better these tstat could be stuck closed also leading to overheating your freshly rebuild ph.
are you running stainles or brass tstats?

 

[reeldutch]

Re: Post rebuild questions

i think youre fine.

but check it anyway to be shure.

 

[hoeser]

Re: Post rebuild questions

Yeah I figured it would be moving much more water through at WOT and that would translate into cooler running temperatures. I have no idea of the composition of the thermostat or any related components, if/when they were ever serviced it was long before I was working on this engine.

They are probably genuine OMC parts if anything though, if that tells you anything.

How long do they typically last?

If it's stuck, I'm glad it's open. Damn thing runs tip top right now.. my original question was probably phrased a little incorrectly, when I said "seems like a lot of carbon build up" I meant "It seems like running double oil would CAUSE a lot of carbon build up" - not unique to my engine... I don't think I'm getting more than anyone else, I just think that this much oil must leave an excess fo carbon.

At lunch I was at about 2000rpm putting up the river for a while, maybe 5-7 minutes and when I dropped the hammer it shuttered for 2 or 3 seconds and dumped a cloud of blue behind me, again, I blame the 2x oil for that... I just wonder if its leaving a lot of waste behind in my engine that should be cleaned out post break-in.

 

[reeldutch]

Re: Post rebuild questions

i wouldnt wurie about it.
after you switch to vro only it will clear it all out.
i would decarb it at the end of the season or after 50hrs of use.
and for the tstats boy they can be stuck ore closed every year.
sometimes they dont give you problems for years and sometimes every season.
keep on flushing the motor out is my advise.
i had more luck with sierra tstats.

i think if your plugs dont look pitch black just a little more oilier you are fine.

you might want to put new plugs in after the double oil period.
the plugs will give you a lot of info how the motor is running with the vro oiling the fuel system.

good luck