72e40e johnson, starts with fuel line off, as soon as i reconnect it, it dies

[Lone Duck]

Re: 72e40e johnson, starts with fuel line off, as soon as i reconnect it, it dies

The hoses on left side bottom are not crossed somehow? Hoses to fuel pump are not crossed are they? Your engine is flooding and not breathing properly.

 

[tjhamms]

Re: 72e40e johnson, starts with fuel line off, as soon as i reconnect it, it dies

Did you get the carburetor repair kit, or did you just get a new float. You said it was properly adjusted. With the kit you will get a small clip that attaches to the needle valve and float. As the float rises and falls the needle valve will open and close. If it had an older float and needle it will not have the clip. Also make sue the float is not installed upside down.

 

[Kjruff]

Re: 72e40e johnson, starts with fuel line off, as soon as i reconnect it, it dies

I got the entire rebuild kit for the carb; float, needle/seat, packing washers, hinge pin for float, the hoses are not crossed. I was ASE certified right out of high school and have been tinkering with weedwackers, go carts, and lawnmowers since I was about 9 years old, so I know what i'm doing, i'm just chasing gremlins and was hoping someone would have an answer. I've gone through all the simple problems and I didn't overlook anything silly like switching lines or hoses or upside down float, or backwards bulbs. I am fairly new to outboards but not to engines in general. I guess I was just hoping someone had an answer about some silly recall or issue these motors had that I didn't know about. im going to try the rebuild kit and see what happens. I also just lubed up all the timing advance plates and every other moving piece on the engine.

 

[oldboat1]

Re: 72e40e johnson, starts with fuel line off, as soon as i reconnect it, it dies

Don't stomp on your laptop now, but you might try bypassing the fuel line connectors at the motor, both the quick release on the line from the bulb and the male connector at the motor. Just go direct from bulb to motor with no connectors in between.

 

[Fed]

Re: 72e40e johnson, starts with fuel line off, as soon as i reconnect it, it dies

After about 1-3 minutes it will suck the primer bulb flat

You have already tried dipping the fuel hose into an open tank so the only thing left is a blockage between that tank end of the hose & the primer bulb.
Filter in that line or blocked at the primer inlet?

 

[tjhamms]

Re: 72e40e johnson, starts with fuel line off, as soon as i reconnect it, it dies

1-"This motor is driving me nuts! please help!" Sorry if my reply offended your ASE certification.
2-"i'm just chasing gremlins and was hoping someone would have an answer. I've gone through all the simple problems and I didn't overlook anything silly like switching lines or hoses or upside down float, or backwards bulbs. " Over looking the basics always come back to bite us in the a**
3-"I have the new float adjusted properly. (pump bulb till it firms up little or no fuel dumps from carb intake.) new needle and seat as well".
4-"im going to try the rebuild kit and see what happens". Why would you throw new parts on top of new parts ?
5-"I was ASE certified right out of high school and have been tinkering with weedwackers, go carts, and lawnmowers since I was about 9 years old, " I'll leave this one for you to figure out !

 

[Kjruff]

Re: 72e40e johnson, starts with fuel line off, as soon as i reconnect it, it dies

oldboat1, I will try that as soon as I get my rebuild kit. thank you that was the most helpful info so far lol. hope it comes before the weekend... but I just picked up a nice gheenoe with a couple holes ive already fiberglassed, so at least ill still hit the flats if I cant figure out my motor before then

 

[Kjruff]

Re: 72e40e johnson, starts with fuel line off, as soon as i reconnect it, it dies

i didn't get the entire rebuild kit the first time around. I got the needle, seat, and float from a local marine store. now that I know the float setting I can bend it once and be done with it. I also got the needle and seat the first time with out the rubber tipped needle. also since the packing washers alone cost almost $40 and the entire rebuild kit was only $24 I mind as well install all the parts while I have the carb off. im not just throwing new parts on new parts, but if ive got the carb off and open and all the parts were cheaper than the four I needed, why not install all new?

 

[Kjruff]

Re: 72e40e johnson, starts with fuel line off, as soon as i reconnect it, it dies

rebuilt the carb with the new packing washers and she runs like a dream. Also installed a new float pivot pin and the new float pre bent to match the one I almost snapped off readjusting so many times. also installed a new impeller while I had my tools out. had it idling and running for 20 minutes yesterday on the boot, today will be a river test.

 

[Fed]

Re: 72e40e johnson, starts with fuel line off, as soon as i reconnect it, it dies

It will be interesting to see if it sucks the primer bulb flat at WOT?

 

[oldboat1]

Re: 72e40e johnson, starts with fuel line off, as soon as i reconnect it, it dies

yup. Hope you will post results after running -- been interesting. Good to hear about the progress!

 

[Kjruff]

Re: 72e40e johnson, starts with fuel line off, as soon as i reconnect it, it dies

took it out on the river two days in a row with flawless operation. She starts right up just like my Silverado now with just a flick of the key! had it running for almost 14 hours in the two days. I idled almost 10 miles up some small backwater creeks (lower wekiva) and ran wide open for almost 30 minutes. I could definitely lean out the fuel mix a bit to get the rpms up and idle a bit smoother but i'm very happy overall. I am also going to change out to a different style of plugs and probably change the condensers/coils/and points for some extra insurance. After building this little boat for almost a year its nice to finally enjoy it!

 

[boobie]

Re: 72e40e johnson, starts with fuel line off, as soon as i reconnect it, it dies

Kjruff, read post # 10 again.

 

[Kjruff]

Re: 72e40e johnson, starts with fuel line off, as soon as i reconnect it, it dies

Yes boobie. I figured it was something to do with the carb as well... pesky two strokes :/ i used to have. Dirtbike and a weedeater back in the day that had a plug in the combustion chamber that would cause it to only run wide open and I heard that these motors also had/have reed valves so I was just hoping not to remove the powerhead! Just happy to finally enjoy the boat after all this time building it!