1982 Evinrude 7.5 carb or fuel pump?

[merkdawg0084]

Hey guys, 1982 7.5. Motor idles great, but when I try to give it full throttle, it dies. Will not start back until I open choke. Pulled carb cleaned everything. Put carb back on and motor is doing same thing? What could be wrong?

 

[boobie]

What happens if you pump the primer bulb ??

 

[rowerowe101]

Sounds like pump to me if you properly cleaned carb and made sure float setting is correct. Have you checked fuel pressure between pump and carb, and if its getting to all carbs?

 

[merkdawg0084]

Boobie I didn’t try to pump primer bulb.

 

[merkdawg0084]

Rowerowe 101 I didn’t pull fuel pump lines yet. It’s getting gas to carb, just won’t really get into full throttle. It’s like you gotta let it catch up?

 

[iggyw1]

Hey guys, 1982 7.5. Motor idles great, but when I try to give it full throttle, it dies. Will not start back until I open choke. Pulled carb cleaned everything. Put carb back on and motor is doing same thing? What could be wrong?

Did you mean it will not start back up until you CLOSE the choke, or OPEN the choke like you stated? After the choke is open and motor is idling fine, there should be a vacuum pulling the fuel out of the carb & into the intake chamber, then forced into the combustion chamber. When you are trying to give it some throttle, cover the carb with a piece of paper & see if there is a suction on the paper so you can tell if the vacuum is there or not. If not, there is a problem with the vacuum sucking the fuel thru the reed valves. Could be the reed valves in that case or maybe a bad intake gasket.

 

[racerone]

If the motor " idles great "----There is no problem with the reed valves !!!

 

[iggyw1]

If the motor " idles great "----There is no problem with the reed valves !!!

I stand corrected. I just thought maybe the reed valves were opening just enough for a great idle, but not opening any farther than a wee bit when you gave her some throttle. This is not possible?

edit: Can he also eliminate a problem with the intake gasket too?

 

[racerone]

Reed valves respond to air pressure !!-----Iggy , time to study the basics of these simple 2 stroke motors.

 

[iggyw1]

Reed valves respond to air pressure !!-----Iggy , time to study the basics of these simple 2 stroke motors.

One last question: Is it possible for the reed vales not to open ( by responding to air pressure) beyond the little bit they are opening to give the motor a great idle? I cannot find anything on line that answers this question. Again, is this a possibility?

 

[merkdawg0084]

No it’s not the reed valves, it will eventually get to full throttle, but it’s like it takes it a few seconds to catch up to the throttle. It hesitates then gets to full throttle,l.

 

[kbait]

If choking helps a warm motor, you have a fuel delivery issue. If carb is full, and low speed mixture jet is set correctly, you most likely have a partially blocked main jet, or contaminated fuel.

 

[merkdawg0084]

Thx Is the high speed jet is a fixed jet in that carb? Looking at parts list doesn’t show it being removed?

 

[racerone]

???---What parts diagram are you looking at ?----Clearly item # 24 is the high speed jet where I look.

 

[merkdawg0084]

Let me look again

 

[merkdawg0084]

Yes racerone #24 is technically the high speed plug. I was wondering if the high speed orifice tube is removable? Thx

 

[rowerowe101]

Rowerowe 101 I didn’t pull fuel pump lines yet. It’s getting gas to carb, just won’t really get into full throttle. It’s like you gotta let it catch up?

Yeah it can get fuel to carbs and still not be the proper pressure. Do your carbs have a high speed screw? and is fuel tank vented?

 

[merkdawg0084]

Only one carb. No high speed screw. And gas cap is vented.

 

[rowerowe101]

I would go through carbs again and confirm pressure after pump is in spec. Ultrasonic cleaning is best for carbs imo.

W.O.T stop screw could be mis-adjusted as well and or throttle cables.

 

[merkdawg0084]

Ok thx. I ordered a new fuel pump. Like 20$. Gonna try that and if that doesn’t fix it, go back through the carb. Just kinda sucks ya gotta pull starter recoil out of the way. Thx. I’ll let ya know.