Fuel pump for 4.5 HP Johnson

[Lancerdad34]

I have a mid 80's 4.5 that stalled out a hand full of times last summer due to lack of fuel getting to the carb. I want to try replacing the fuel pump. I did check the filter and it was clean. Attached is a photo. I am hoping someone can steer me to the right part.

Thanks,
Brian in MI

 

[flyingscott]

They make a rebuild kit for those. Easy to do just watch out for the little springs. Pretty sure this is it. Stay away from the cheap chinese $20 ones they are nothing but trouble. A factory pump is $170 the rebuild kit is $16

0393088​

 

[tphoyt]

Agreed go with the rebuild. Your pump is far better quality than what’s out there in the aftermarket stuff.

 

[Lancerdad34]

Agreed go with the rebuild. Your pump is far better quality than what’s out there in the aftermarket stuff.

Thanks for the replies!

 

[saltchuckmatt]

Interesting, typically a visual inspection is enough but just pump the primer ball while running and see if it clears up.

 

[saltchuckmatt]

More likely a carb issue.

 

[jitterbug127]

I rebuilt one of these for the first time recently. Pretty easy to do. Brandon's garage has a really nice video. Easy to follow.

If you decide to buy a new one Sierra has a good fuel pump for around $50. I've had one on my 15 hp for a good year no without issue.

 

[racerone]

Those PRESSURE driven pumps are simple and reliable.----Might need just a diaphragm.----But as stated , use the manual fuel pump and report what happens when you use it.

 

[Lancerdad34]

Interesting, typically a visual inspection is enough but just pump the primer ball while running and see if it clears up.

Pumping the bulb did not seem to matter. It was very random cutting out. One way I found to get it running was spraying starting fluid in the carb. It would start right up and stay running.

 

[Lancerdad34]

Those PRESSURE driven pumps are simple and reliable.----Might need just a diaphragm.----But as stated , use the manual fuel pump and report what happens when you use it.

Thanks for the reply! I am leaning on just going ahead and rebuild the pump. I can try it out in my backyard. The thing about this issue was it was random not good when trying to troll for walleyes!

 

[racerone]

Inspect your fuel line from bulb to tank including INSIDE the tank !----Many newer plastic tanks have pick up tubes that are plastic junk.

 

[saltchuckmatt]

85 to 90 percent dirty carb IMHO. Be careful with the starting fluid in a two stroke...there's no lube in the fuel.

 

[Lancerdad34]

Inspect your fuel line from bulb to tank including INSIDE the tank !----Many newer plastic tanks have pick up tubes that are plastic junk.

Thanks never thought of that!

 

[Lancerdad34]

85 to 90 percent dirty carb IMHO. Be careful with the starting fluid in a two stroke...there's no lube in the fuel.

One question. Can fuel pumps be bad randomly? The stalling out was very random last summer.

Thanks,
Brian

 

[racerone]

What other trouble shooting has been done on this motor.-----The 2 big tests are compression.----Post your numbers here.---Does spark jump a gap of at least 1/4" or more on both leads ?

 

[saltchuckmatt]

Like race says, could be many things...

Mix some outboard oil with gas in a small fuel grade spray bottle (50 to 1)? And spray in carb throat when acting up.

Did that correct it?

Fuel pump is normally not random.

Sinister piece of floating debris zipping through the carb laughing at you? Good chance.
Hot coil not producing energy also laughing at you? Could be.

Get a wooden stake or silver bullet and send it back to hell!

 

[Lancerdad34]

What other trouble shooting has been done on this motor.-----The 2 big tests are compression.----Post your numbers here.---Does spark jump a gap of at least 1/4" or more on both leads ?

Checked compression before I bought the motor. Good spark. This issue is so random it is hard to figure out. I had days where it ran good for over 4 hrs before I quit fishing for the day. I am thinking of putting a clear line from the pump to carb so I can see the fuel flow (or not).