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35HP Dripping Gas Out Exhaust

D

dwjohnso

New member
Hi, I have a 1978 35 Evinrude 2 cyl. with one single carb, that has raw gas coming out of the inner part of prop when sitting on trailer. Seems to have started after I reinstalled the head from having to replace the head gasket, also had head decked while off. That may only be a coincidence though. It has 120# on one cyl. and 115# on the other. I also just replaced the plugs and the power pack before I realized the gas problem.

Boat will crank and run great once I dry out and clean plugs, for about 5 minutes, then seems to lose one cylinder. Plugs always wet when removed but bottom plug always seems wetter. I have cleaned carb a couple times and float does not appear to be sticking. At this point I'm pretty sure carbs are flooding but not sure how, any help ?? Thanks
 
Also, along with checking the fuel pump diaphragm (as below)... check that the carburetor is not flooding/leaking.

********************
(Fuel Pump Diaphragm Test)
(Two Hose Type Only)
(J. Reeves)

Note: This pertains only to the regular Two Hose type fuel pumps.

Leave the hoses attached to the fuel pump. Remove only the two screws that attach the fuel pump to the powerhead. Re-insert those two screws and install a nut to each of them so that the fuel pump is securely clamped together. With the fuel line attached to the engine, pump the primer bulb while observing the pressure/vacuum operating hole on the back side of the fuel pump. Should any fuel leak out that hole, the diaphragm is faulty.

If the diaphragm is faulty, the fuel pump will require rebuilding or replacing. Note that repair kits are not available for all fuel pumps, in which case replacing the pump would be necessary.

********************
(Fuel Pump Diaphragm Test)
(Three Hose Type Only)
(J. Reeves)

Note: This pertains only to the regular Three Hose type fuel pumps.

Remove only the pressure/vacuum hose that leads from the fuel pump to the crankcase. Leave the other hoses attached. With the fuel line attached to the engine, pump the primer bulb while observing the pump pressure/vacuum fitting that you just removed the hose from. Should any fuel leak out that fitting, the diaphragm is faulty.

NOTE: If the carburetor is obviously flooding, clamp the hose shut that leads to the carburetor.

If the diaphragm is faulty, the fuel pump will require rebuilding or replacing. Note that repair kits are not available for all fuel pumps, in which case replacing the pump would be necessary.

********************
 
Thank you very much for the helpful replies. I will check the diaphragm asap. I did find a parts list for my model (35802R) and it does appear if I'm looking at the right one correctly, there is no rebuild kit avaibale. I will have to check and see how many hoses come from the pump as I don't remember.
Let me ask, while checking the fuel pump in this manner, can I also tell if the carbs are flooding as well at the same time or is there another good test for the carbs?
Thanks
 
I am quite sure that a diaphragm or rebuilt kit is available.----Just take the time to look at parts lists for various years / models and compare.
 
dwjohnso said:
Can I also tell if the carbs are flooding as well at the same time or is there another good test for the carbs? Thanks
Click to expand...

Very easily.... Simply have the engine in a vertical running position (Engine NOT Running) and pump the fuel primer bulb up hard while observing the carburetor. While holding pressure on the primer bulb, if the carburetor is flooding, fuel will flow from it from somewhere.
 
Wonderful help, thank you guys very much.
When you say to compare my diaphragm to other years for a replacement, would you mean to take mine apart and try to find a pic that resembles mine from a parts list? I have to get back home and troubleshoot the methods I have been given first to determine the fault, I have been away from home this weekend. Thanks again
 
Facts for you.-----These fuel pumps are very simple.----They work using the PRESSURE pulses from the crankcase.-----They are often replaced as a trouble shooting " hail mary " attempt to fix a motor.-----I do not know what pump is on your motor at this time.----Bring it over and I can fix / replace the diaphragm for you.
 
Thank you sir for those facts, and I would take you up on the help if you were down the road. I'm in SC over near the coastline at Myrtle Beach. I feel pretty good about being able to repair the pump if I had the correct parts in hand. After I diagnose the problem correctly with you guys help, I'll dive into the repair. I did find a parts listing for a new pump, but at $99 I think I'll try to find some parts first.
I gotta get this running better for my son soon, it's on a 12ft strip boat and he duck hunts with it and he's all excited about this year already. Thanks
 
Update on the fuel pump test, my pump is the triangle shaped 2 hose pump.... leaks really bad out the hole in the middle on the back of pump, I believe this is the pulse hole that lines up with the crankcase, so it test bad or faulty. Still no luck finding replacement parts so looks like I may get an aftermarket one off e bay, $20 china made I imagine but looks to be a entire new pump.
Primer bulb would not pump up tight in order to check carb for flooding due to fuel leaking out the pump, but pretty sure the pump is bad.
 
dwjohnso said:
Update on the fuel pump test, my pump is the triangle shaped 2 hose pump.... leaks really bad out the hole in the middle on the back of pump, I believe this is the pulse hole that lines up with the crankcase, so it test bad or faulty. Still no luck finding replacement parts so looks like I may get an aftermarket one off e bay, $20 china made I imagine but looks to be a entire new pump.
Primer bulb would not pump up tight in order to check carb for flooding due to fuel leaking out the pump, but pretty sure the pump is bad.
Click to expand...

Yep... That indicates a leaking diaphragm alright!
 
Update ! Problem Solved
Thanks a million guys, the new fuel pump seems to have fixed the issue. Boat is running super good, even idles lower than ever with no missing, that may be due to the several carb cleans I did or even the new power pack I replaced but either way, what a nice running boat now, again THANKS for all the help, advice and replies
 
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