1974 Evinrude 25hp wont run.

[OptsyEagle]

I am not sure where precisely you are on your motor problems since it appears you are fixing around 3 different motors but I can't be sure. As for the fuel pumping issues, if you are running these motors in a barrel make sure your gas tank is on a table or something held up about as high as the motor head. These old fuel pumps can struggle sucking gas up from a gas tank on the ground to the height of the motor head. In a boat that elevation never happens and it might be too much for the low pressure those fuel pumps provide to suck fuel into the carb.

 

[Dalejam]

before blowing $$$$ in suspected air leaks just wrap them up in cellophane tightly to prevent air leaks ... retry .


you must be the unluckiest man in the oldies world at 130 posts ...

i ask alot of questions, realising they are general. so i try to be more spacific, so i get more of a direct answer to my problem. thank you for the celifane idea. but when i squeeze the ball for gas it leaks badly, new clamps didnt help that much.

thank you for the help and idea
Dale

 

[racerone]

The pumps operate on crankcase PRESSURE and most pumps have no trouble pulling fuel up 4 feet.-----Fix any and all leaks including inside the tank.

 

[Dalejam]

I am not sure where precisely you are on your motor problems since it appears you are fixing around 3 different motors but I can't be sure. As for the fuel pumping issues, if you are running these motors in a barrel make sure your gas tank is on a table or something held up about as high as the motor head. These old fuel pumps can struggle sucking gas up from a gas tank on the ground to the height of the motor head. In a boat that elevation never happens and it might be too much for the low pressure those fuel pumps provide to suck fuel into the carb.

i keep the tank about a foot lower then the head of the motor now. i do have multiple motors, but the two motors have the same powerhead, so i ask questions to just the one motor, anything i learn from that i can use on the other. i do appreciate all the help, hopefully will be done with this motor by the weekend.
as for running it in a barrell close enough i am running it in a rubbermaid garbage can, the motor does not hit the bttom about 3 inches off it. so it is running with alot of water.
thank you for all the help and replies
Dale

 

[clemsonfor]

i watched some videos to see about the suction or pressure depends on how you look at it, but most say 1lb, the problem is unless you hook a gage to the line and add a T so fuel can still go to motor when running. you wont feel it if you put your finger over the hole? so out of the three motors i have, none of them create enough that i can feel. then again old cracky fingers from being a worker. but seriously is there any other way to tell on the pulse ?

I do have to get the new fuel line and primer and connector's in. to eliminate a good amount of my issues. didnt realise how much havic it can cause if you are sucking in air through the fuel delivery system.

thanks as always for all the help and information.
Dale

Out of the two 25hp one fuel pump has to be good. You get the same thing if you swap them? I can't remember what you said about rebuilding them now but it's simple and it works. Just buy the Evinrude or Sierra kit...it will be fine. If the engine has compression it will give a pulse to work the fuel pump.

 

[clemsonfor]

i ask alot of questions, realising they are general. so i try to be more spacific, so i get more of a direct answer to my problem. thank you for the celifane idea. but when i squeeze the ball for gas it leaks badly, new clamps didnt help that much.

thank you for the help and idea
Dale

You can use automotive fuel line to test it out. Readily available and cheap.but Walmart sells the lines unless you like me and it's a 50 mile or so round trip and you don't go into town every week or so. But now a days with Amazon and walmart.com they bring it to your house. But for me prime means 3 days if your lucky and more like 3-7 days

 

[racerone]

The motor needs crankcase compression to operate these simple pumps.----It appears you are totally confused by ignition coils under the flywheel and the driver coil under the flywheel.---And is there one set of magnets or 2 Inside the flywheel ??---n brvgffffr

 

[davidmbv]

The pumps operate on crankcase PRESSURE and most pumps have no trouble pulling fuel up 4 feet.-----Fix any and all leaks including inside the tank.

 

[Dalejam]

The motor needs crankcase compression to operate these simple pumps.----It appears you are totally confused by ignition coils under the flywheel and the driver coil under the flywheel.---And is there one set of magnets or 2 Inside the flywheel ??---View attachment 359492n brvgffffr

-It appears you are totally confused by ignition coils under the flywheel and the driver coil under the flywheel ????? i think i might be the way you are asking me.
i thoiught the driver coil was the one that would produce Voltage to go back to the battery to charge it. the Ignition coil was the one that would create the spark then send it to the coil to be amplified so spark is greater ? yes there is 2 sets of magnets under the fly wheel apossing each other only one coil on the top of the motor,
thanks for helping.
Dale

 

[racerone]

The driver coil is to produce voltage for the ignition coils to step up to 30.000 volts at the plugs..-----A battery charging coil would be in addition to that driver coil , with yellow wires going to a rectifier.----Do you have a rectifier ??----Have you tested the driver coil ?----With 2 sets of magnets it is the correct flywheel for your motor.-----And 12 volts from a battery is not used to make spark for the sparkplugs !-----So test that driver coil !!

 

[Dalejam]

The driver coil is to produce voltage for the ignition coils to step up to 30.000 volts at the plugs..-----A battery charging coil would be in addition to that driver coil , with yellow wires going to a rectifier.----Do you have a rectifier ??----Have you tested the driver coil ?----With 2 sets of magnets it is the correct flywheel for your motor.-----And 12 volts from a battery is not used to make spark for the sparkplugs !-----So test that driver coil !!

No i dont have a rectifier yet. i will look for that system after i get the motor to run better.

 

[racerone]

So you miss-understood the purpose of the driver coil.----Once again I am blunt.----If you are not sure how things work then the trouble shooting / repair may take a long time.-----We are now at post #151 and counting.----

 

[clemsonfor]

Post #152 now

 

[Dalejam]

So you miss-understood the purpose of the driver coil.----Once again I am blunt.----If you are not sure how things work then the trouble shooting / repair may take a long time.-----We are now at post #151 and counting.----

Thanks for being BLUNT, I just went and reread what was stated about driver coil and coil packs that go to the spark plug.
To be BLUNT I wrote it down incorrect so you were right to tell me. But I do understand what the process is. Driver coil sends voltage to the ignition coil that steps it up. Simple but that is its function.
If this thread is too long then tell me I will end it,
People get very touchy when people ask alot of questions . We may not have the answer or correct answer, but that is why we are here.

Serious if this is annoying the moderators for the amount of posts. Someone write to me and tell me. I will be happy to seperate my inquires and ask them as individual posts.

Thank you all for your Help & time.
Dale

 

[Roadking57]

The driver coil is to produce voltage for the ignition coils to step up to 30.000 volts at the plugs..-----A battery charging coil would be in addition to that driver coil , with yellow wires going to a rectifier.----Do you have a rectifier ??----Have you tested the driver coil ?----With 2 sets of magnets it is the correct flywheel for your motor.-----And 12 volts from a battery is not used to make spark for the sparkplugs !-----So test that driver coil !!

On my 25R73A with a driver coil can a charging coil be added?

 

[racerone]

The answer is yes.------Since many folks are challenged with 12 volts and wires I can not offer instructions.

 

[Roadking57]

I watched one of Danger marine's videos. (guy with british accent). He used a small rectifier from yamaha. Ran two wires from charging coil to it then red/white to battery, and a ground to block. I think it was a 20hp. Anyway it produced 13.8vdc at a little above idle. I dont know yet if that p/n he showed is still available. I just figured before I reassemble my engine I could install one.

 

[Crosbyman]

plain full wave diode rectifiers are all over the Amazon cheap and high capacity with different shapes to mount. cost vary widely chose what fits the wallet .

they are not regulators !! just rectifiers if that is what you need. I would mail you one ( I bought several years ago) but postalshipping fees ..being a " parcel" would be over the amazon prices :-(

https://www.amazon.ca/KBPC5010-Silicon-Bridge-Rectifier-Single/dp/B07S4LQ9GL/ref=sr_1_9?crid=26QNBM0YX7CH0&keywords=full%2Bwave%2Brectifiers&qid=1651322973&sprefix=full%2Bwave%2Brectifiers%2B%2Caps%2C99&sr=8-9&th=1

 

[Dalejam]

So you miss-understood the purpose of the driver coil.----Once again I am blunt.----If you are not sure how things work then the trouble shooting / repair may take a long time.-----We are now at post #151 and counting.----

so i have done some trouble shooting over the weekend to see if i can figure out fuel issue with the motor.
1) purchased new gas, used the Penzoil oil as suggested.
2) replaced all fuel lines on motor
3) ran motor with gas in carb to see if pressure was coming out to make diaphram move, took fuel pump off so i could feel pressure, could hear it and feel it
4) purchased new hose and squeeze bulb, new clamps no leaks.
5) cleane carb,
6)purchased rebuild kit for carb, installed. turn carb upsidedown and tried blowing into the inlet no air allowed, turned it correct oreintation and blow into inlet air allowed.
7) purchased new fuel pump from AMAZON , used on motor
8) rebuilt another fuel pump from papers that some one posted to me on how too rebuild pump.
9) start motor, runs for a few then stalls, squeeze ball is not full. if i open carb nut on the front no gas drains out of it, but if i squeeze the ball gas will fill carb and come out where i removed the nut.

so question is could it possibly be the float is not dropping enough. seems to allow air to go in and out but taht is me turning the carb upside down.
i have looked for videos to find a answer to this question. when the motor is running should the pule from the crank case be enough to get fuel to come out of the fuel line to the carb ? or does it take the carb to be connected to the line for the system to function porperly. for i have disconnected the fuel line to the carb when motor is running but no fuel comes out of line. just trying to troubleshoot ????


open to suggestions ?????
Thank you all
Dale

 

[racerone]

Answer this question only.-------When you pull the recoil handle a few times , does fuel come out of the pump , yes or no ?