need help, gas dumping into #2 cyl and wont stay running

[Andy in NY]

okay, heres the deal. my buddy rebuilt the carbs and fuel pump for me, im at his place right now in massachusetts 300 miles from home.

when i squeeze the bulb, fuel runs out from the intake and exaust and collects in the #2 cyl. the bulb never gets hard.

when I can get it running it will stay running if you pump the bulb. we aslo bypassed the pump all together with a soda bottle with gas mix in it, and it stayed running when you squeeze it.

my friend is very famaliar with auto mechanice, but not really with marine stuff. im going home sunday and would like to try to fix this asap. if anyone can help me with some advice i would appriciate it.

maybe someone has time to give me a call? my cell # is 518 353 2834. or respond here.

 

[ondarvr]

Re: need help, gas dumping into #2 cyl and wont stay running

First we need to know what engine you have, year, HP, etc.


If the bulb won't get hard and fuel just flows through the motor, then the floats are stuck, or installed wrong. You need to pull it back apart and check them.

As for the fuel pump, I don't know anything about merc pumps, but you'll need to check it also.

What type of problems were you having before the work was done?

 

[Andy in NY]

Re: need help, gas dumping into #2 cyl and wont stay running

First we need to know what engine you have, year, HP, etc.


If the bulb won't get hard and fuel just flows through the motor, then the floats are stuck, or installed wrong. You need to pull it back apart and check them.

As for the fuel pump, I don't know anything about merc pumps, but you'll need to check it also.

What type of problems were you having before the work was done?

right, forgot... its a 1966 merc 500.

the problem i was having was that it was a dog under load, so a carb rebuild was recommended. both were rebuilt, as was the fuel pump. after being reinstalled it dumps fuel right into the #2 cyl. we put a clamp on the line going to the carbs, and it seems like its dumping fuel via a passage that is behind the pump that goes into the #2 cyl.

 

[ondarvr]

Re: need help, gas dumping into #2 cyl and wont stay running

I had to leave and go to class for a couple hours.


The fuel pump has a problem then. The pump works by sensing the pulses from that cylinder and moving the diaphragm, there should be no pass through of fuel into the cylinder. Sounds like you need to take it apart again.

 

[rosser1]

Re: need help, gas dumping into #2 cyl and wont stay running

sounds like fuel pump diapham may be wrong and or needle and float stuck

 

[Andy in NY]

Re: need help, gas dumping into #2 cyl and wont stay running

the passage from the cylinder, is there any kind of check valve in there that would stop the fuel from flowing directly into the cylinder?

 

[ondarvr]

Re: need help, gas dumping into #2 cyl and wont stay running

For fuel to pass through it into the cylinder right after a rebuild means it wasn't put together correctly. You need to pull it apart and do it again.

 

[jimg984]

Re: need help, gas dumping into #2 cyl and wont stay running

hoses are hooked up wrong

 

[Andy in NY]

Re: need help, gas dumping into #2 cyl and wont stay running

IT RUNS!!!

Seems that my buddy put the pump together and forgot the actual diaphram!

but now its not peeing...

 

[CharlieB]

Re: need help, gas dumping into #2 cyl and wont stay running

Any chance that your 'Buddy' was starting the motor with NO WATER supply?

The water pump impeller will be toast and maybe the upper pump housing also.

Drop the lower unit and LOOK.

 

[Andy in NY]

Re: need help, gas dumping into #2 cyl and wont stay running

Any chance that your 'Buddy' was starting the motor with NO WATER supply?

The water pump impeller will be toast and maybe the upper pump housing also.

Drop the lower unit and LOOK.

ya, we just finished replacing the impeller, and when we reinstalled the lower unit it wont shift back to neutral (the manual said to put it in forward gear to remove the unit). any ideas?

 

[Andy in NY]

Re: need help, gas dumping into #2 cyl and wont stay running

well we finally got everything all set and just got back from a test run... she did great! 27mph on gps... not bad for a 14 footer... but REALLY slow to plane. but shes up and running.