evinrude rough starting and slow speed/carb job

[neil12]

motor has been starting rough and hesitation when hitting the gas. so i took the carbs apart and soaked them in carb cleaner, and used a air compresser to blow the jets out, all the rubber and needle looked great. some where down the line one of the floats got bent in the bag i was holding all the little parts in.. I bent it to where the float was slighty below the carb when holding it upside down. so i put everything back together and tested the motor out and now I have the same problem but it is even worse motor shakes when in idle.. could the float be my problem or what do you think it might be????? its a evinrude 1994 90hp looper v4

 

[neil12]

Re: evinrude rough starting and slow speed/carb job

Anyone have any ideas?? Im thinking maybe the floats are set wrong should they be even with the carb? Thanks!!

 

[ezeke]

Re: evinrude rough starting and slow speed/carb job

Whenever the carburetors are moved, as when cleaning, or for whatever reason, it is required that they be replaced airtight to prevent upsetting the delicate mixture of air and gasoline, so new gaskets should always be used. Additionally, the carburetors must be synchronized so that they open and close at precisely the same time. The throttle plates should be fully closed at idle and perfectly horizontal at WOT (Wide Open Throttle). The importance of these steps can never be overstated because it is impossible for the engine to run smoothly without them, especially at idle speed.

The synchronization of the carburetors requires two steps: first the individual carburetors have to be synchronized with each other; then the carburetor linkage has to be adjusted so that the roller of the cam follower aligns precisely with the embossed mark on the throttle cam while almost touching the cam. Any attempts to adjust these settings other than directly on the carburetors? linkage will usually only make things worse. The throttle cable should be disconnected while making these adjustments.

Once the carburetors are perfectly synchronized and the roller set to the embossed mark on the cam, the throttle cable should be adjusted so that it slips on without causing any movement of the linkage at the engine. To allow for tension, move the throttle arm on the remote control fully forward and back to neutral before adjusting the cable.

 

[neil12]

Re: evinrude rough starting and slow speed/carb job

Thanks for your reply! ok i checked the plates and they are fully closed at idle but at WOT they are about 80% open how could i fix that? I moved one screw on the choke adjustment arm???? and when i stated it the motor ran like it was stuck wide open! So i put it back where it was. I took a picture before I took it off so I know it is where it was before.

 

[neil12]

Re: evinrude rough starting and slow speed/carb job

I forgot to put that the motor runs great once giving a good amout of gas it is just on idle and low gas when it runs rough!

 

[ezeke]

Re: evinrude rough starting and slow speed/carb job

Thanks for your reply! ok i checked the plates and they are fully closed at idle but at WOT they are about 80% open how could i fix that? I moved one screw on the choke adjustment arm???? and when i stated it the motor ran like it was stuck wide open! So i put it back where it was. I took a picture before I took it off so I know it is where it was before.

You do not have chokes or choke adjustments; those were replaced long ago by the primer solenoids which is the device with the red handle (which handle should be aligned with it's cylindrical base).

You have throttle plates which need to be perfectly synchronized so that they open at exactly the same time and reach WOT, or precisely horizontal, at exactly the same time.

 

[neil12]

Re: evinrude rough starting and slow speed/carb job

ok it is the throttle plate arm i adjusted and put back. so do i just need to adjust the arm or is there another way? I took a pic of it and it looks like it is the same as before i took it apart. Thanks!

 

[neil12]

Re: evinrude rough starting and slow speed/carb job

here is a pic of the throttle plates in idle.

 

[ezeke]

Re: evinrude rough starting and slow speed/carb job

Click the thumbnail, please.

Disconnect the throttle cable.

Loosen the lower carburetor level adjusting screw.

Open the throttle shafts and let the throttles snap closed. Press down on the top of the link to remove the backlash and tighten the screw. Check that the throttle plates are now synchronized.

Loosen the throttle cam follower screw.

Adjust the cam follower with the throttle valves closed, so that the cam follower is centered on the embossed mark but not quite touching the cam.

Move the throttle on your remote control all of the way forward and back to neutral.

Using the thumbwheel on engine end of the throttle cable, adjust the cable so that it slips on without moving the engine linkage, and reconnect.

 

[neil12]

Re: evinrude rough starting and slow speed/carb job

Thanks for all your help. I did everthing in your last post and its runing much better, although its still not 100%. It starts up great runs good in idle at first. I drove the boat around the lake and it runs great but when I come back to idle it dies unless i have the motor trimed up. When the motor is down it dies every time. This sucks because anytime you have to go in reverse and then into foward it dies unless you flip it into forward really fast. please help lol

 

[ezeke]

Re: evinrude rough starting and slow speed/carb job

Now that you have the carburetors set up, you need to adjust the idle so that it is at 650 RPM in gear, in the water, unrestrained, with the engine warmed up. You should probably start at around 750 - 800 out of gear.

Turn the idle screw clockwise to increase speed, counterclockwise to lower it. Use small adjustments; if you go too fast you will damage your gears when shifting. See the thumbnail.

 

[neil12]

Re: evinrude rough starting and slow speed/carb job

ok 650 RPM in gear. Do you mean in fwd just past neutral?

 

[ezeke]

Re: evinrude rough starting and slow speed/carb job

ok 650 RPM in gear. Do you mean in fwd just past neutral?

Correct. No warm-up lever.

 

[neil12]

Re: evinrude rough starting and slow speed/carb job

I just got back from the lake I was going to set the idle like you told me. I backed the boat in started it up and i heard a clicking sound coming from the back of the motor i leaned over with one hand on the rim of the motor and leaned in a little further with the other hand then ZAP!!!!!!!! I got the crap shocked out of me! So I look at the motor without touching it with two hands, i saw that the socket part of one of the spark plug wires is on the spark plug still but the wire itself is just hanging there. Do you think my problem has something to do with a wire that was going bad? or something that just happed to happen. I may have even ripped it off when i took the cover off although that would mean it was not on there real good in the first place.

 

[ezeke]

Re: evinrude rough starting and slow speed/carb job

You definitely need to be sure that your plug wires are good. I like the pre-booted ones that come with the CDI ignition coils, but I don't know the part numbers for just the wires; maybe the sales staff here at iboats could help with those if you give them a call.

 

[neil12]

Re: evinrude rough starting and slow speed/carb job

I was able to fix the spark wire so its back on. I took the boat out currently the boat idles at about 1100 rpm (motor up a little) the motor wont idle all the way down. With the motor just in gear it runs about 850-900 rpm kinda sounds like it wants to die but stays running with motor down all the way, but runs strong with it up a little at this speed.

I idled it down the wayyou said and of course it just died so it is back to the above setting where it was before.

 

[ezeke]

Re: evinrude rough starting and slow speed/carb job

It's hard on the gears to shift at that RPM.

If you did not rebuild the carburetors step-by-step according to your service manual, you should consider doing them again.

 

[neil12]

Re: evinrude rough starting and slow speed/carb job

I got a manual for my motor and redid the carbs with new gaskets! It might be running a little better but still likes to die in idle. Im going to get new spark plugs and gap them. I dont really think it is the spark plugs but i guess its worth a try.