Help

[CarrierSquid]

I have 2 issues.

1. When in a hose the engine runs fine. Better than fine like new. But when i put it in water it looses RPMs like a big dog and dies many many times. I have replaced the fuel filter and the fuel lines. My thought is I need to either rebuild or replace the carb. I have also replaced the alternator, the plugs and wires and tuned the carb that is on there now.

2. I loose vacume when I throttle it up in the water. Again works fine on the hose. Replaced PCV valve and sealed the one vacume line that i have found.

Any input will be of great help!!!

Info on engine:
1973 Mercruser I/O
165 Horse
Inline 6
any more info needed please let me know

 

[jerryjerry05]

Re: Help

Sometimes that can be the sign of a bad coil.Or the shift interupt switch is opening.Possible shift cable replacement or adjustment.
Start it up.See how hot the coil gets.You should be able to touch it without burning.
Measure the voltage to the coil.Should be about 9 volts.
Somethings to think about.J

 

[CarrierSquid]

Re: Help

I did replace the shift intrupt switch when i got it. It wouldnt go into gear at all before i did that. Which coil are you talking about? and i did adjust and reset the shift cable to the manufactures specs...

Oh forgot to add.... it does run great in the water for about 2 min and then looses it....

 

[zbnutcase]

Re: Help

I did replace the shift intrupt switch when i got it. It wouldnt go into gear at all before i did that. Which coil are you talking about? and i did adjust and reset the shift cable to the manufactures specs...

Oh forgot to add.... it does run great in the water for about 2 min and then looses it....

The shift interrupt switch is for coming out of gear, not going in to gear.

 

[CarrierSquid]

Re: Help

will that cause it to loose RPMs?

 

[Bondo]

Re: Help

2. I loose vacume when I throttle it up in the water.

Ayuh,... Have you done a Compression Test,..??
How do ya tune a faulty carb,..??

It surely sounds like it's starving for fuel,...
What to the sparkplugs tell you,..?? What color they runnin',..??

Vacuum is caused by the throttle plates closing the intake throat,....
When the throttle plates are Open, there's little restriction, hence little Vacuum....

 

[CarrierSquid]

Re: Help

Yes i have done a compression test. It was fine... i tuned the carb by turning it back to zero and starting over. like i said ran GREAT on the hose... but put a load on it and runs like CRAP!!!

I havent rechecked the spark plugs after i replaced all of them. so cant answer that question.

with the vacume issue... will replacing the carb possibly fix that??

yes my spelling SUCKS!!!

 

[LemmyAce]

Re: Help

I had similar issue. would run fine in the driveway but once in the water it would stall when putting it in gear. turned out to be the shift linkage was sticking. Try taking the linkage off the engine and moving the shift cable that goes to the outdrive. it should move smoothly. try the same with the control cable. Mine was the linkage inside the drive. but i wasnt loosing vacuum and it sounds like you can get in gear

 

[Vanover]

Re: Help

If you just leave it in nuetral on the water will it die? If it is a fwd/rvr gear problem maybe timming is off and you are not advancing. If it runs in nuetral regardless i would check the plugs for lean/fouling and get a timming light and check it out.