Evinrude 25 Lean sneeze

[Hunter12345]

Good morning,

I have a 25 Evinrude E25TEECB. I am at a loss as to why I cant figure this out. Every time I take the boat out I have to spend 10 or 20 minutes re-adjusting the syncronization, low speed mixture, and idle screw. after I do that the motor seems to run fine. The next time Im out when i start it it will be misfiring, sneezing, or running extremely rough. I occasionally hear a knocking noise coming from the power head that sounds to me like pre ignition. I have the service manual and have followed the instructions exactly reguarding the sync. I have no problems at full speed except for occasionally it will take a longer than usual time to get on plane. I have done a lot of work on this motor, including; Rebuilt carb w/ carb kit, and float at correct height according to service manual, rebuilt fuel pump with new diaphrams and gaskets, new spark plugs, wires, and good coils with proper resistance, new power pack, new solenoid, and new battery cables. I have removed the flywheel to make sure nothing is installed incorrectly on the magneto.

Any advice will help a lot. Thanks

 

[racerone]

Adjust the rod on the side of the block so that carburetor opens a little later.----Remove slow speed mixture needle and post picture of the tip.-----In my opinion this should be an easy fix.

 

[Hunter12345]

Adjust the rod on the side of the block so that carburetor opens a little later.----Remove slow speed mixture needle and post picture of the tip.-----In my opinion this should be an easy fix.

Are you talking about the throttle control rod?
And I dont have the motor with me but i will do that again, when i rebuilt the carb the needle was very pointy as is should be. Thank you

 

[saltchuckmatt]

Is it sneezing at idle in nutruel or when you go to take off it hesitates?

With those motors, on the link and sync you want the timing to advance a little before the carb starts to open.

 

[Hunter12345]

It is sneezing in neutral and in gear. I also hear a slight knocking noise around 1000 rpm.

There is no hesitation when i give it throttle.

and i have it set so the cam follower pickup point is between the two marks like the service manual states. So yeah the timing does advance a little before the carb butterfly starts to open. But when i do that the idle screw is almost turned all the way in.

Thanks for the response!

 

[Hunter12345]

Is it sneezing at idle in nutruel or when you go to take off it hesitates?

With those motors, on the link and sync you want the timing to advance a little before the carb starts to open.

Sorry my last post was supposed to be a reply to you

 

[F_R]

Are you sure it is in need of fixing? A bit of lean sneezing when starting up is normal till it warms up a bit. Simply "bump" the choke a bit to keep it running.

 

[Hunter12345]

Are you sure it is in need of fixing? A bit of lean sneezing when starting up is normal till it warms up a bit. Simply "bump" the choke a bit to keep it running.

this model has the primer system and no choke plate in the carb. ive worked on many 31.8 OMC blocks and never had one this difficult to figure out. And sometimes itll sneeze to the point that it dies.

Ive also noticed excessive smoke compared to the other motors but i assume they all smoke a little different.

Thank you for the response!

 

[racerone]

Maybe a defective lower crankshaft seal.

 

[Hunter12345]

Maybe a defective lower crankshaft seal.

Would that also be causing excessive smoke? If i do the lower crank seal would you recommend doing anything else while i have the powerhead off and apart?

Thank you!

 

[stresspoint]

when i get a 2 smoke that has a sneeze i spray some carb cleaner around the intake area , well basically i drown the motor in the **** .

one place to also spray carb cleaner is into the air fuel mixture screw on the smaller 2 cylinder motors if it idles up there is your issue ,

 

[racerone]

Perhaps post video of the motor running and sneezing.-----This should not be hard to figure out.----But that is my opinion and others may disagree.

 

[Hunter12345]

Perhaps post video of the motor running and sneezing.-----This should not be hard to figure out.----But that is my opinion and others may disagree.

i will run the motor and post a video as soon as i can. and i agree this should be an easy fix. ive done a bunch of these 31.8 blocks and never had one that was this difficult.

Thank you

 

[goat lady]

Good morning,

I have a 25 Evinrude E25TEECB. I am at a loss as to why I cant figure this out. Every time I take the boat out I have to spend 10 or 20 minutes re-adjusting the syncronization, low speed mixture, and idle screw. after I do that the motor seems to run fine. The next time Im out when i start it it will be misfiring, sneezing, or running extremely rough. I occasionally hear a knocking noise coming from the power head that sounds to me like pre ignition. I have the service manual and have followed the instructions exactly reguarding the sync. I have no problems at full speed except for occasionally it will take a longer than usual time to get on plane. I have done a lot of work on this motor, including; Rebuilt carb w/ carb kit, and float at correct height according to service manual, rebuilt fuel pump with new diaphrams and gaskets, new spark plugs, wires, and good coils with proper resistance, new power pack, new solenoid, and new battery cables. I have removed the flywheel to make sure nothing is installed incorrectly on the magneto.

Any advice will help a lot. Thanks

I have a 40hp Johnson that did that, here is how to fix it, nothing wrong but need the carbs tuned, take the throttle cable loose, now snap the throttle controll rod loose on the front end, adjust it so it measures 7 and 13/16 inches from center of each socket, loosen the the carburetor lever adjustment screw on top carb, and work the carbs with your finger, let both carbs snap back closed and look back into the carbs from the front, making sure the little butterfly flaps are completely closed, if they are closed now hold up on the top carb adjustment screw and tighten it back up, now watch and make sure both carbs start to move at the same time, open the carbs full throttle and look back inside the carbs again, if both butterfly flaps are in the same open position, let go of the throttle and see if both butterfly flaps snap back to a fully closed position, if either one is open the least bit it will still sneeze, make sure both fully close, now adjust both the cam and cam follower so the pick up mark is pointing to the center of the little cam follower roller and tighten the screw, now push the idle speed screw tight against it’s stop, and look to see if the spark lever cam follower is between the two alignment marks, now turn the mixing screw all the way in on both carbs and count the turns you make backing the screws out back them out three full turns, if it is still lean and sneezing continue to back both carbs out 1/4 turn up to 4 full turns if needed, with three turns out and the sneeze has stopped, you can close them a 1/4 turn or more to find the sweet spot without a sneeze, it won’t hurt anything to back them out three turns or four if it takes it to stop the lean mix, now if it idles without sneezing, connect the throttle cable back up, you may have to screw it in or out to fit the new adjustments you have made, note if it is idling good before you connect the throttle cable back up and you should try and give it fuel at the carbs with your finger to speed up the rpm’s it will sneeze again because the timing won’t advance to burn the extra fuel, after connecting the throttle cable then everything will work together, hope this helps,

 

[Hunter12345]

I have a 40hp Johnson that did that, here is how to fix it, nothing wrong but need the carbs tuned, take the throttle cable loose, now snap the throttle controll rod loose on the front end, adjust it so it measures 7 and 13/16 inches from center of each socket, loosen the the carburetor lever adjustment screw on top carb, and work the carbs with your finger, let both carbs snap back closed and look back into the carbs from the front, making sure the little butterfly flaps are completely closed, if they are closed now hold up on the top carb adjustment screw and tighten it back up, now watch and make sure both carbs start to move at the same time, open the carbs full throttle and look back inside the carbs again, if both butterfly flaps are in the same open position, let go of the throttle and see if both butterfly flaps snap back to a fully closed position, if either one is open the least bit it will still sneeze, make sure both fully close, now adjust both the cam and cam follower so the pick up mark is pointing to the center of the little cam follower roller and tighten the screw, now push the idle speed screw tight against it’s stop, and look to see if the spark lever cam follower is between the two alignment marks, now turn the mixing screw all the way in on both carbs and count the turns you make backing the screws out back them out three full turns, if it is still lean and sneezing continue to back both carbs out 1/4 turn up to 4 full turns if needed, with three turns out and the sneeze has stopped, you can close them a 1/4 turn or more to find the sweet spot without a sneeze, it won’t hurt anything to back them out three turns or four if it takes it to stop the lean mix, now if it idles without sneezing, connect the throttle cable back up, you may have to screw it in or out to fit the new adjustments you have made, note if it is idling good before you connect the throttle cable back up and you should try and give it fuel at the carbs with your finger to speed up the rpm’s it will sneeze again because the timing won’t advance to burn the extra fuel, after connecting the throttle cable then everything will work together, hope this helps,

Thank you for such a detailed response. unfortunately mine is a single carb, but i will look at completely disconnecting everything and sync the motor from scratch as you said.

thanks again

 

[oldboat1]

fuel/oil ratio might be too lean, if running premix. Use 50:1.

 

[racerone]

This 25 HP motor never came with oil injection.

 

[Faztbullet]

Crankcase leak or seal issue. Since it stops after using it , thermal expansion will seal crankcase.

 

[Hunter12345]

fuel/oil ratio might be too lean, if running premix. Use 50:1.

i run 50:1 or richer if im going to be full throttle a lot

 

[Hunter12345]

This 25 HP motor never came with oil injection.

yeah its not i mix it in the tank