75 evinrude carb adjustment

[jherlyn]

I have had a long journey with this engine, and I have another question. It is a 1975 Evinrude 75 hp Hustler.

The engine would idle fine in driveway, but I took it to the lake, and it wouldn't run. So I took it home, and found out it was only running on 2 out of 3 carbs. tested compression, all valves at 125 psi.

Cleaned all three carburetors, and it ran great in drive way. I didn't kit them. I know it needs to be done, but I was hoping to wait till the off season to do it. I also cleaned the fuel filter. It honestly didn;t look that bad.

Now it idles in the water, but when I go to shift it dies. It's not the linkage, because I looked at that. It almost seems that the carbs are flooding. Ok, so I go to adjust the carbs......and I'll be damned if I can find the adjustment.

Now maybe I'm just stupid here, but WHERE ON EARTH are the carb adjustments on these carbs. All accessible screws on the outside that I would possibly be led to think would be adjustments are screwed in tight. IS THERE A CARB ADJUSTMENT ON THESE THINGS?

 

[Daviet]

Re: 75 evinrude carb adjustment

There are no adjustments on your carbs, they are fixed jets.
It sounds like your idle might be a little low, should be about 700-750 IN gear, if it is to low it will stall when put in gear.

 

[jherlyn]

Re: 75 evinrude carb adjustment

Thanks for the fast reply, I feel like an idiot because I just figured that out, so I might have to pull them again and run a wire through them or something. But another question, could it be the fuel pump causing this too? I adjusted the idle and it didn't really help. Whenever I shift or ramp the throttle the motor makes a sneezing, mild backfire sound, and then sputters like its going to die. And depending on how fast its idling, it'll just bog wwwwwaaaaaaayyyyyy down or flat out die. Does it sound like I might still have gunk in the low throttle orifices?

 

[Daviet]

Re: 75 evinrude carb adjustment

Try having someone pump the primer bulb constantly and see if it helps, this will bypass the fuel pump.
The way you are describing it, it sounds like the carbs may need to be overhauled.

 

[jherlyn]

Re: 75 evinrude carb adjustment

Yeah we pumped the ball to no avail. I'll pull the carbs apart again (for the third time) and try to pull the low speed and high speed orifice plugs out and clean them out with wire, and then soak them again. Any suggestions to pull the low speed orifice out? It just doesn't seem like they make a screw driver with a shaft skinny enough to get down in the hole with a flathead big enough to get a good bite on the orifice so you don't f***k it up.

 

[Daviet]

Re: 75 evinrude carb adjustment

They make a special tool for it. I just reground a screw driver to fit.

 

[jherlyn]

Re: 75 evinrude carb adjustment

Ok, so just got done checking the carbs. The low speed orifices were as clean as they could be, and so were the high speed orifices. I even went as far as doing a lync and sync just to make sure (even though I didn't change anything to begin with.) And I also ran a needle through the orifices just to make sure. I saw a little gunk in the top housing where the low speed orifice sets on the top carb, so I cleaned it out.

What's frustrating is it will idle, shift, and throttle up wonderfully all day long in the driveway, but it won't in the water. So it's not like I can just test it.

So I'm sure it still will disappoint me at the lake, however......

When I hooked it up to make sure it would at least still run, I noticed that the gas connection on the motor was seeping gas. It has to be the motor side because I JUST REPLACED the fuel side. Could this be causing it? I know its bad, and I am getting the part, but do I still need to look at my fuel pump as the main culprit, or what???

Any suggestions/thoughts would be REAAAAALLLYYY helpful.

Thanks

 

[Daviet]

Re: 75 evinrude carb adjustment

If the fuel system is leaking fuel, itcould also be sucking air.
What is your idle speed, should be about 750 rpm IN GEAR in the water, not on a hose.

 

[Monte1961]

Re: 75 evinrude carb adjustment

If the carb/s are factory and still have the old cork floats in them? If so get rid of them or you will be fighting this in-till you do!

 

[jherlyn]

Re: 75 evinrude carb adjustment

My idle speed is fine, right where it should be.

As far as the cork floats, I dunno. Like I said, I am going to kit these things, I would just like to wait till the off season. What would the old cork floats do that could be causing this, especially where it idles and ramps up perfectly in the driveway, but not in the lake.

Even with the idle way up, in the lake, the minute you hit the throttle, the motor sneezes and then bogs down. It'll idle just fine all day in the lake, until you ask it to do something, which screams to me fuel starvation. the fuel connection makes sense, but so does the fuel pump. I just don't know what to do next. I'm replacing the fuel connection hopefully tomorrow depending on whether the store has the part, but what are my chances that this is the problem or the fuel pump?

 

[levi_tsk]

Re: 75 evinrude carb adjustment

i agree with monte and daviet...
fix the connection, try it, if it still does it kit the carbs i can get brp full kits(new floats needles seats and viton gaskets) for around 25 each shipped (a little less if you get three at a time)

i know that 75 bux seems like alot of dough but think of it this way my tohatsu kits cost me 140 for three... and all the parts for it are like 50+ each at least youve got a johnnyrude and parts are cheap and readily available
this motor i have's only saving grace is that it came with a nice boat and trailer and only cost me 800 bux but ive got a 50rude waiting in the wings if it give me ANYMORE crap

so kit the carbs and do the fuel pump for another 20 bux if that doesnt fix it pm me if you want my contact for the carb kits

 

[jherlyn]

Re: 75 evinrude carb adjustment

woah, wait a sec, 20 bucks for the fuel pump? where are you getting that price, last I checked the fuel pump was 100. If you're getting the fuel pump for 20, lemme know where.

 

[levi_tsk]

Re: 75 evinrude carb adjustment

no for a rebuild kit for the fuel pump theyre super easy to do sorry for the confusion however i CAN get a new pump for around 70

 

[jherlyn]

Re: 75 evinrude carb adjustment

Where are you finding the kits at. From all the parts breakdowns I have seen, it seems that you can rebuild the fuel filter assembly, but I haven't seen an actual fuel pump rebuild kit. Are you finding them at Crowley Marine or somewhere like that? Because 20 bucks doesn't sound so bad. Please let me know.

 

[Monte1961]

Re: 75 evinrude carb adjustment

Carb kit w/ float about $18.00 a piece here at iboats! have them in stock!

 

[levi_tsk]

Re: 75 evinrude carb adjustment

Where are you finding the kits at. From all the parts breakdowns I have seen, it seems that you can rebuild the fuel filter assembly, but I haven't seen an actual fuel pump rebuild kit. Are you finding them at Crowley Marine or somewhere like that? Because 20 bucks doesn't sound so bad. Please let me know.

theres a couple of different pumps and thus a couple of different kits to match can you post a pic of your fuel pump please ?

 

[levi_tsk]

Re: 75 evinrude carb adjustment

i think this one is for yours it was the only 75 hp kit listed .... DO NOT BUY ANYTHING WITH A GASKET MADE BY SIERRA -complete GARBAGE BRP has switched to Viton gaskets to hold up the ethanol- seirra hasnt done that yet and thats why theyre cheaper ALSO the BRP kits come with detailed instructions sierra doesnt and if youve never done one before, i HIGHLY reccomend the instructions
alright this isnt My parts guy but you see where im going with this
http://cgi.ebay.com/ebaymotors/OMC-...4946559QQptZBoatQ5fPartsQ5fAccessoriesQ5fGear

 

[jherlyn]

Re: 75 evinrude carb adjustment

OK, so let me list everything I have done to this motor:

Pulled and cleaned all 3 carbs
Cleaned low and high speed orifices with needles/carb cleaner
New fuel line connection on hose end
new fuel line connection on motor end of fuel hose
performed link and sync
rebuilt fuel pump with good fuel pump kit
cleaned fuel filter
made sure I was idleing at the right speed in water in gear

IT"S STILL NOT RUNNING RIGHT!!!

Here's what it does (In water not on hose)
It will start and idle just fine
It will shift into gear and push the boat
It WILL NOT idle up! The minute I do, it just bogs down, sneezes and dies!! If you shut the engine off and restart it, it restarts immediately. However, if you let it bog down and die, then you need to run the starter for a while with the choke on, then it will start and immediately die. Then hit it once more real quick and it fires right up. If you pump the ball while you rev it up slowly, it will eventually climb to higher RPMs. So, it;s starving, but why.

Interesting part is when you rev it up while squeezing the ball, when the motor sneezes the ball will go immediately flat, like it dumps a Sh*t ton of fuel somewhere. Now, there are no leaks, so could it be a stuck float? I am really stumped and frustrated here, so any help would be nice.

 

[levi_tsk]

Re: 75 evinrude carb adjustment

ok you said it sneezes ? thats called a lean sneeze and its usually a fuel problem .... i know youve cleaned the carbs a couple of times now but did you take the high and lowspeed orafices out?? it only take a micro spec of crud to mess up the whole darn thing ...
did you hose everything with carb cleaner or drop it in a can of carb dip overnight?

you might be able to dip the carbs and not pull the orifices but you probably wont break all the gunk loose with just a can of carb cleaner hosed up inside its stong stuff but you just cant beat a good overnight dip... unless you do a full dissasembly and an overnight dip the tool for those jets is only 20 bux or you can take a grinder to a screwdriver and make your own, if you want ill take a pic of mine and post it up here so you can see what your shooting for

it could be a needle and seat sticking or the float or anything else in the carb but its deffinitely in there somewhere but its not getting enough fuel and when it "sneezes" its sucking the bowl dry and the fuel line too and blowing the fuel out of the front of the carb which is why its a pain to restart after it does that the bowl(s) are empty

if you were to take the air box cover off and make it lean sneeze youd see a spray of fuel coming out of the carb(s) the wrong way and its actually a backfire of sorts two strokes cant really backfire as they dont have any valves and the reed valves prevent it from coming out of the intake manifold for the most part - becareful because if it is lean sneezing and im amost certain it is it can damage your reed valves


have you checked the timing?? the top secret files have the link to a way to do a link and sync without taking it out on the lake or running the engine

 

[retiredfornow]

Re: 75 evinrude carb adjustment

Just a note. Mine is a 60hp rude, and it was doing the same thing, and I did the same thing that you did, and rebuilt the carbs. I did the WOT timing in the Top Secret file and the timing was 9 degrees off!!! This motor was on a boat I just bought and I never ran it before. Has your motor ran good at one time, like last year? If it's new to you, then check the timing. Mine runs like a new one now. Good luck!