75 evinrude carb adjustment

[keykev]

Re: 75 evinrude carb adjustment

yeah, timing would be something to check to . i would try tweaking it a little bit here and there. also, you say fuel bulb emptys quickly, i am sure you have done this but is tank vent open and not pluged, is your fuel good, no water, maybe pump a sample into a glss jar to check. i think in 1975 they still had a manual choke, you can try partial choke in water with an assittant to see if that helps accellation and lean sneeze. you can also try the old trick of bringing rpms up alittle bit and closing choke momentarly. it may be ashot in the dark but this could pull through the little speck of dirt you may have missed, good luck.......

 

[F_R]

Re: 75 evinrude carb adjustment

jher, it sounds to me like maybe your timer base is sticky. That makes it lag behind the carburetor butterflys' opening and that will cause immediate lean stalling. Bottom line, the carburetors must not open too soon, in relation to the degrees of spark advance.

BTW, running wires through the jets is very poor practice. They are precision holes, easy to damage. Just a word to anybody else contemplating it.

 

[jherlyn]

Re: 75 evinrude carb adjustment

Could somebody post a link to the top secret file? I am not lazy, just Veeeerrryyy busy, and it could be the timing I could see that. I did dip the carbs in carb cleaner for the recommended time, twice, and I have pulled the orifices completely out.

Is the timing easy to do? I actually have a stock tank now that replicates it in the water, saves me a hell of a lot of money to the boat dock, and embarrasment from all the other boaters who seem to think I don't know what I'm doing.

Thank you for your help.

 

[levi_tsk]

Re: 75 evinrude carb adjustment

yeah it is easy - all you need is a timing light and to know how many degrees of timing its sposed to be advanced (look in your manual )

heres the procedure remember whatever your book says subtract 4 degrees and thats the number youre looking for with your timing light good luck man i know this things been giving you a time

http://forums.iboats.com/showthread.php?t=228183

 

[jherlyn]

Re: 75 evinrude carb adjustment

alright, so I checked the timing, and there is a problem there, but I just don't know what yet, so....more help please.

With the throttle at full and the base timer all the way at the stop, my timing light off of the top piston reads 24 degrees. according to my boat motor, it needs to be advanced to 16. If I take the four off like J Reeves said, then it should be 12.

The problem is, once I get the base timer to 12, it doesn't look like my adjustment screw will come out that far. At the same time, when I let go, the spring in the arm bounces forward again, like even if I could get the screw adjusted there, it's still not right because I have overextended the spring.

So here's my questions. First, is the top piston the one I should be timing (is it the first one in the firng order?) second, am I missing something adjustment wise here and it's a simple fix, or is there something else wrong such as maybe the base timer? I am pretty certain fixing this will help, but I don't know what to do.

Thank you for your help.

 

[levi_tsk]

Re: 75 evinrude carb adjustment

heres a pic of your power head
these guys may correct me but the screw on the top is the one you should adjust

 

[jherlyn]

Re: 75 evinrude carb adjustment

Okay, so I give up

The thing just absolutely FLAT refuses to run right. I know the carbs are good because I can see fuel spraying from the high speed orifice tube and from all the little tiny holes in the valve body.

Yet, EVERYTIME I REACH FOR THE THROTTLE it sneezes, no power, NONE!!. Talked to a 30+ year boat mechanic today, and he won't even listen to the timing idea saying that it has NOTHING to do with timing. Plus, he tells me to time it is actually a little more complicated than what the forums say. Guy's down to earth, so I believe him.

I took this motor off to paint the boat, and then put it back on. Then I replaced the frozen shift and throttle cables cuz they were bad. Could my problem be somewhere in the linkage? I dunno anymore, I have tried everything!!

I am giving it this weekend, if there are no more bright ideas, I'm taking the thing to a mechanic and telling him I don't want to see the god forsaken thing till it runs right......in gear......IN A TANK WITH A LOAD ON IT. And I'm going to want to see that happen before I pay the bill with my own two eyes.

*** ****** I'm frustrated!!!!!!!!!!!!!!!

 

[jherlyn]

Re: 75 evinrude carb adjustment

Oh, one more thing from my post above that I find interesting

So it won't run right, my dad took a squirt bottle of premix fuel and squirted it into all 3 cylinders to see what it does. First and second cylinders it flooded it, third cylinder it didn't do anyhting. It didn't rev it up, it didn't bog it down. So I pull the spark plug thinking no spark while it was running, and it bogs down when you pull the spark plug off. So......adding fuel doesn't affect its performance either way, but pulling the spark plug off bogs it down? What's that about? Is that a sign of weak spark, misplaced timing, what?

 

[Daviet]

Re: 75 evinrude carb adjustment

You know, this one is a head scratcher. Just some thoughts. It will drop #3 if you pull the plug wire but will not flood out by squirting fuel in the carb. Just grasping at straws but, swap the top and bottom carb, redo the fuel squirt thing and see if the problem moves from #3 to #1, if so the problem has to be in the carb. If the problem stays on #3, swap coils between #1 and #3, and retest, if problem stays on #3 you must have an internal engine problem on #3. You basicly swapped fuel and ign and the problem did not move, the only thing left is internal on #3. I didn't notice, what was you compression?

 

[jherlyn]

Re: 75 evinrude carb adjustment

125 on all three cylinders. I am just wondering what it might be. I am wondering that if the carburetor is working in a weak manner causing my sneezing issue. I too am grabbing at straws. Hopefully the compression numbers help.

 

[Daviet]

Re: 75 evinrude carb adjustment

The compression should be ok, a little low but it should run ok. The only other thing I can think of at the moment is reed valves.

 

[jherlyn]

Re: 75 evinrude carb adjustment

I think I am going to do what you said and switch the two carbs around tomorrow and see if the problem follows the carb. I am also going to double check the spark to make sure its not weak.

I might even pull all the fuel hoses apart and double check them. This way I can get the bottom carb to the top and watch how it operates in a better angle. Make sure all the low speed jets are spraying and whatnot. Its hard to see when its at the bottom.

How do you know when a base timer is bad? Is there a way to test it? The timing thing still has me scratching my head because it doesn't seem right to me even though the mechanic says that I don't know what I'm looking at or how to adjust. I will give him that fact though, I really don't when it comes to timing. It just seems that when I move the throttle assembly farther back, which moves the base timer arm, It runs really crappy. And if I move the whole assembly forward, it runs really good. could it be the spring on the throttle arm that moves the base timer, because that doesn't seem right either. is it supposed to be sitting right against the stop in the idle position. just thoughts running through my head. If there really is a problem in that linkage, I might have to have a mechanic look at it, way above my head, ya know? It's just that I question whether I got the linkage adjusted right when I put the new shift and throttle cables on and the problem that I am having is self made.

Look at me....I'm rambling.

 

[levi_tsk]

Re: 75 evinrude carb adjustment

dont worry man we all do it especially when we're frustrated ... and sometimes it helps
you say you changed the cables? i dont remember you mentioning that before ... try taking the throttle cable off and making sure that it slides RIGHT on when the engine is in neutral and the idle lever is all the way in the down position - if it doesnt then adjust it to were it does .... you dont want to move the throttle lever even a milimeter to get it on there -it can throw everything off

 

[jherlyn]

Re: 75 evinrude carb adjustment

O.K. so I adjusted the throttle to where you said it should be and then switched the carbs around. While I was at it I took all questionable connections out of the fuel lines (factory zip ties and such) and even inspected the connecting tee and blew through the hoses to make sure there was no clogs.

fired the engine up..

It still has problems. It's raining today so i could only get it on a hose and not in a tank. Here are my findings. The top and middle carb flood out when you spray premix gas into them. The bottom one picks up, but just oh so slightly. If you pull the spark plug out while the engine is running on the bottom plug, not much happens, but when you put it back on, it seems to surge and then quiet back down. I know you guys are going to say carburetion, but I moved the carburetor that WAS acting up, and now its fine, the problem stayed with the cylinder.

Funny thing is, when I start the engine, every now and then the starter will actually stop the engine, like its trying to make it turn backwards. I'm thinking it's a timing issue, especially because now it seems to have a pretty constant sneeze just idleing. And when I say timing issue, I think something has gone bad on the motor, like the base timer, and it's beyond just an adjustment. so......off to a boat mechanic it goes. I mean, I'm gettin to be pretty good with these things, but not that good.

Any thoughts or suggestions would be helpful, considering it's not going in for at least a couple days (memorial day weekend and all) Also, just in case I'm right, and the base timer is shot, anybody got a connection to a base timer for a 75 Evinrude 75 Hp Hustler? They don't make them anymore, and I'm fearing having to track down the part.:facepalm:

 

[levi_tsk]

Re: 75 evinrude carb adjustment

oh they make em .... but you wont like the price...... but you could do it yourself and save on labor?? to make up for the cost? im sure one of these guys here can tell you how to test it
http://www.marineengine.com/newparts/part_details.php?pnum=CDI133-1251&ptype=&Engine=&Model=

make a stator ...http://www.marineengine.com/newparts/part_details.php?pnum=CDI173-1235&ptype=&Engine=&Model=

power pack too....
http://www.marineengine.com/newparts/part_details.php?pnum=CDI113-1726&ptype=&Engine=&Model=

ill tell you what though lets back up and assume its nothing fuel related .... have you got a hairdryer or a heat gun and a multi meter??

 

[jherlyn]

Re: 75 evinrude carb adjustment

yeah, I do.....wwhhhhyyyy......

 

[levi_tsk]

Re: 75 evinrude carb adjustment

heat up your coils one at a time with the hair dryer set your multi meter to 2k ohms and test the windings first the primary and then the secondary

this is what your coils look like right?

test the primary windings which will be the black wire to the fins that should be about 50-100 ohms and the secondary will be orange to black and that should be 500-600 ohms do it while the coil is warm to the touch as itll expand and expose any breaks in the windings do this with all three coils
if you get no continuity or a dirrect short the coils bad

follow this procedure to test the power pack- but do it while its warm to the touch as sometimes the diodes will pass at room temp but fail once the engine warms up the pack
http://www.cdielectronics.com/InstallSheet/113-1726.pdf
if after that youve got nothing take it to the mechanic ... im all out of ideas

 

[jherlyn]

Re: 75 evinrude carb adjustment

(steps up to microphone, puts on glasses, and clears throat) I......cornelius m. lancaster the third (not my real name btw)....am.......an.......IDIOT!

first off...I can't figure out how to run those tests with the multimeter. Maybe I have the wrong one. but ALL my readings are way off from what they say. Far enough that if they are right, the engine shouldn't un at all. but while I was looking at the wiring, I noticed that when I switched the coils around when I thought there was a problem there, I didn't reconnect a ground (thwack!!:facepalm I reconnect that wire and fire up the engine, the sneeze is gone. But there's a miss.

Now I'm assuming that I messed up the coil because that ground wire was prolly shorting through it. So I move the coil down to the third cylinder, to see if the problem follows the coil. I fire up the engine, and still there is a miss, so I pull the third spark plug to see if the miss goes away, and the motor LOCKS. I mean locks hard, like a fuel lock. I put the third plug back on and restart the engine. Now the idle is adjusted a ways up, because I was told it was idleing too low. the engine just fricking ROARS to life. I had to kill it because its RPMS went way too high. Now, all of a sudden, this thing runs MEAN, just MMMEEAAANN! You can hear the blade whir and its pushing the boat forward, without the prop in a tank.

So what changed? Did I fix something temporarily with that engine lock, or is it fixed? once it stops raining I'll tank test it just to make sure, but this is the best its ever run while under my watch. Do I need to switch that coil out? Or is that a sign of a failing power pack? I just don't trust it because I really didn't fix anything. It runs now, and I have more questions than EVER!! Anybody have any ideas? I'm thinking I should change that coil out, just to be sure, but what do you guys think?

 

[levi_tsk]

Re: 75 evinrude carb adjustment

that IS really strange... could have been a loose or bad connection..... sometimes its just that simple..... BUT:

coils are 25 each... if it where me id replace em all with the newer style coils AND the power pack..... which is 75-80 that would pretty much rule out ANY ignition problems

oh and i messed up telling you were to set the multi meter - my bad the primary should be 200 ohms and the secondary should be set to 2k(thats probably why you were getting funky readings)

 

[jherlyn]

Re: 75 evinrude carb adjustment

where are the coils 25 each. The ones here are 47 each, and the power pack is like 150. So if you souldn't mind telling me where, I just might go ahead and replace them.