1991 25hp evinrude starting issues

saltchuckmatt

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I will try to get a video tomorrow

I have it in an enclosed 55 gallon trash can. I have had it on ear muffs but the same issue.

I will set everything to what the book says to. I would line the cam roller up between the two marks but it won’t kick over. Then I would turn the throttle plate screw in a few turns where the cam roller is just past the second mark. It will then start, then I would adjust the idle speed screw starting at 1 1/2 turns then adjust it tell it sneezes then turn back a quarter of a turn.

Seems to be idle good put as soon at I go up on the throttle it starts to die. To me it’s seems that it’s not getting the right air to fuel mixture or the timing just doesn’t stay. I have messed with the air intake and fuel so many times.

But there is not much to timing on these things. It does seem to me that the throttle cam plate sticks, when I loosen the screw all the way out seems like it won’t move all the way back with it.

Hope this makes some since
Okay, and your letting it warm up before you play around with the low speed idle jet I assume.

Other than components like reed valves and such it sounds fuel related. When you rebuilt the carb how bad was it inside?

Did you clean every passage ways completely?

In the carb throat at the top is two or three tiny holes. When the carb is off and you turn it upside down I pour carb cleaner in there and see if it drains down those holes. Tough to know if those are clean.

I recently worked on one and when I pulled the carb it was missing it's nozzle. It looks removable but it's not.

Is your bowl plastic on that engine?

Any pictures of the carb when you worked on it.

I use welding tip cleaners when I take carbs apart.
 

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racerone

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?----Post #9 says it has a new flywheel key.----All indications are that this motor is in fine shape.----I step aside here.
 
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Okay, and your letting it warm up before you play around with the low speed idle jet I assume.

Other than components like reed valves and such it sounds fuel related. When you rebuilt the carb how bad was it inside?

Did you clean every passage ways completely?

In the carb throat at the top is two or three tiny holes. When the carb is off and you turn it upside down I pour carb cleaner in there and see if it drains down those holes. Tough to know if those are clean.

I recently worked on one and when I pulled the carb it was missing it's nozzle. It looks removable but it's not.

Is your bowl plastic on that engine?

Any pictures of the carb when you worked on it.

I use welding tip cleaners when I take carbs apart.
 

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racerone

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Some testing on your part needs to be done !-----When a motor like that is shifted into gear it should not struggle / nearly stall like yours !!!-----Find out what is wrong with your motor.-----Plenty of suggestions have already been posted for you.-----Remove top plug wire.-----Try and start motor on bottom cylinder.------Repeat test by removing bottom plug lead.---See if it will start on top cylinder.
 

stresspoint

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may not be your issue but i will put it out there for concideration.
i worked on a 25 that the owner had used an incompatible powerpack that appeared to be engaging the engine kill circuit when the throttle was advanced.
when i disconnected (from memory going back a few years ) black / yellow wire it ran fine , so i replaced the power pack with the correct part number one ,it worked fine from then on.
 
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Okay, and your letting it warm up before you play around with the low speed idle jet I assume.

Other than components like reed valves and such it sounds fuel related. When you rebuilt the carb how bad was it inside?

Did you clean every passage ways completely?

In the carb throat at the top is two or three tiny holes. When the carb is off and you turn it upside down I pour carb cleaner in there and see if it drains down those holes. Tough to know if those are clean.

I recently worked on one and when I pulled the carb it was missing it's nozzle. It looks removable but it's not.

Is your bowl plastic on that engine?

Any pictures of the carb when you worked on it.

I use welding tip cleaners when I take carbs apart.
Here is some pics all holes are clean
 

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saltchuckmatt

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Frustrating I'm sure.

Have you been under the flywheel? If so was it clean? Did you replace anything and if so we're those components aligned properly.

Could be one cylinder but it seemed like it leaned out and quit at the end of your video.

Have you tried a portable gas tank....wondering if you have a tank problem.
 

racerone

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There is a high speed jet ( orifice ) in the very bottom of the float bowl.----Is it the correct size and clean ??----Is the nozzle gasket in place ??
 
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saltchuckmatt

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There is a high speed jet ( orifice ) in the very bottom of the float bowl.----Is it the correct size and clean ??----Is the nozzle gasket in place ??
Which would be part number 20 and 22.

Also I can't tell, is part number 1 in?
 

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Some testing on your part needs to be done !-----When a motor like that is shifted into gear it should not struggle / nearly stall like yours !!!-----Find out what is wrong with your motor.-----Plenty of suggestions have already been posted for you.-----Remove top plug wire.-----Try and start motor on bottom cylinder.------Repeat test by removing bottom plug lead.---See if it will start on top cylinder.
Good catch the number 1 fires right up and the second one tries but doesn’t
 

racerone

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Some will argue.-----You might need to look into compression issues in the crankcase.----Possibly a bad lower crankcase seal .---Possibly a reed valve issue.
 
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That is a good idea but i already did a compression test both 105, also a leak down test both less then 10 percent.
 

racerone

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As I said " some will argue "-----Compression in the crankcase has nothing to do with compression in the cylinder.----I would say that you do not fully understand the finer points on your motor.----The reed valves could be missing and you will still get good compression in the cylinder !!!----Hurry to a shop and get help !
 
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As I said " some will argue "-----Compression in the crankcase has nothing to do with compression in the cylinder.----I would say that you do not fully understand the finer points on your motor.----The reed valves could be missing and you will still get good compression in the cylinder !!!----Hurry to a shop and get help !
 
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Thanks for the information not everyone knows everything. If I wanted to take it to a mechanic I would have. I hope one day you don’t need help and someone tells you you don’t know the finer things about it and hurry up a pay someone to do it. LMAO
 
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