View Full Version : Carb issues with 25 horse 1996 merc
raptorschild
12-08-2008, 09:01 PM
What do you guys think.......
I fired up my motor all year with no reliability issues at all.....then went duck hunting the other day, and the motor wouldnt fire. Checked the spark plugs and they were not wet and they were good. I replaced them anyway because the gap looked a little wide.
Anyway....We bought a can of ether and sprayed it in the motor and she fired up, and then died as soon as the ether burnt off.
So....fuel is in the fuel filter, yet it is not getting through the Carb.
Who thinks this will be expensive?......I suppose the fuel could be bad or too much oil....but she fired up great only 2.5 months ago??? Maybe the first thing I should do is change gas and add fresh oil?
Anyway....hopefully i don't need to replace the carb...the motor looks clean and flawless under the cowling!
I will give an update after I take into the boat mechanic...hopefully he doesnt take advantage of my dumb arse!
I love the money pit that is a boat!
bigredapes
12-09-2008, 07:38 AM
stuck float valve?
take a stick or wrench and tap (lightly) on the float bowl on the carb. Generally that will unstick a float valve.
fishkisser
12-09-2008, 08:00 AM
Drop the float bowl on the carb and clean the jets after you remove the water and gunk in there ... next fuel tank stick some marine sta-bil in there ...:twocents:
I wouldn't use ether. To dry, need some oil.
Clean your carb(s). And check for water, like Barney said use Stabil.:)
Clean the carburetor jets. Use a air pressure hose to blow the jets out. Then be sure and drain the Carb or run it completly out of gas after you use it for the day. Never leave it stand with gas in the Carb for more than a week. Always run the engine to completly empty the Carburetor, when you stop for the day. Some engines have a drain valve for this purpose. If your engine has this feature you will not need to run it empty at the end of the day.
If you do this, you will not need to use any other additives to the gas.
Good Luck
raptorschild
12-09-2008, 03:43 PM
Thanks guys.......I'll mess with the carb myself and see what happens.
fishkisser
12-09-2008, 04:08 PM
There is cause for debate on draining the fuel every time your motor is run ...
I have found having your float bowl empty of fuel will cause white powdery oxidation to form that will break loose upon filling and clog jets and passages in your carbs ...
Also the fuel evaporating over repeated times in the tiny jet metering holes will cause varnishing and restrict the fuel metering and change the way your motor runs ...
I prefer to treat all my fuels with sta-bil and I never drain my carbs and have had no problems in many many years of doing it this way ...:twocents:
Barney ...:wave:
I have no doubt what the problem is. The fuel pump is a rubber diaphragm in the carb. Ethanol infected gasoline will rot the diphragm. A rebuild kit costs about 65-75. Send the bill to the brainiacs in Congress who thought Corn was a good substitute for petroleum based gasoline.
Pelagic Captain
12-10-2008, 09:39 PM
What do you guys think.......
I fired up my motor all year with no reliability issues at all.....then went duck hunting the other day, and the motor wouldnt fire. Checked the spark plugs and they were not wet and they were good. I replaced them anyway because the gap looked a little wide.
Anyway....We bought a can of ether and sprayed it in the motor and she fired up, and then died as soon as the ether burnt off.
So....fuel is in the fuel filter, yet it is not getting through the Carb.
Who thinks this will be expensive?......I suppose the fuel could be bad or too much oil....but she fired up great only 2.5 months ago??? Maybe the first thing I should do is change gas and add fresh oil?
Anyway....hopefully i don't need to replace the carb...the motor looks clean and flawless under the cowling!
I will give an update after I take into the boat mechanic...hopefully he doesnt take advantage of my dumb arse!
I love the money pit that is a boat!
I had this same engine only a 98 model...same problem ...the darn thing would not start after leaving it sit for a few days...it's not getting any gas...after 3 visits to the shop ..the last 2 on their dime..apparently the needle valve sticks and will not let gas flow through the carb. My fix was simple...everytime the engine was run when we finished the gas hose was unhooked and the engine was run dry..this drops the float and lets the needle valve to drop out of the flow chamber...never had another problem