Logo
FULL SITE MENU

57 merc Inboard problem

R

rossb

New member
"I am hoping someone can help.

"I am hoping someone can help.
When I start the boat it seems to be making a knocking sound and vibrates the whole boat. When I give it gas the knocking and vibration goes away. The other issue I am having is that the boat will accelerate untill about quarter throttle and then bog and will not go any faster, are both issues related? Is this a carb issue or something else?"
 
"[quote]Is this a carb issue [

"
Is this a carb issue
Click to expand...

You might have More than 1 Issue going on,.....
But,....
I'd Start with the Fuel Filters,+ Carb.......

How Long has it been since this motor was given a Full,+ Complete Tune-Up,..??...."
 
"Sounds a little like an ethon

"Sounds a little like an ethonal water absorption problem, perhaps compounded with a clogged high speed jet."
 
I always hit the 'post&#39

I always hit the 'post' button and think of something else that very instant...

If you pump the throttle does want to rev up normally or puke?
 
I found out that the boat sat

I found out that the boat sat for 2 years. Yesterday I drained 20 gallons of two year old gas from the tank and filter. Any other ideas?
 
"Replace the filter, put fresh

"Replace the filter, put fresh gas in it and run it on the rabbit ears until you get all the bad gas purged out of it. Probably wouldn't hurt to change the spark plugs or at least pull them out and clean them... if it's been sitting that long, a full tune is probably money well spent.
I'm getting in the habbit of putting fuel stabilizer in it all the time. It's hard to find non-ethanol treated fuel anymore and that stuff loves to soak up water. If your in a high humidity area, like Virgnia Beach, and it sits even for only a few weeks, you can have problems."
 
"Thanks,
I will try that toni

"Thanks,
I will try that tonight. I live in Florida, it can get a little humid (all the time)."
 
"Re-formulated gas starts to g

"Re-formulated gas starts to go bad in about three weeks, according to someone I talked to at a shop that does nothing but work on fuel systems (carbs and injection). Two year old gas should smell really bad- not like fresh gas at all. I would have thought the odd odor would have been an immediate tip-off. I would also buy a volume type fuel pump (NAPA or most other car parts stores sell them) and a piece of fuel line, so you can pump the bad gas out rather than run the motor on it. You should be able to take it to a marina or auto service shop to dispose of it. If you can look into the tank through the fuel sender hole, it may be a good idea to dump a gallon of denatured alcohol in, slosh it around and remove it, to get rid of any sludge or additional water from the tank. Wipe any obviously bad stuff out and reassemble, then re-fill the tank. run it for a while before replacing the fuel filters, in case more garbage is sent from the tank, so you don't waste the new filter. Changing it again in a month wouldn't be a bad idea, either. Any metal fuel lines may be corroded inside, so look in the bowl on the carb to see if there's any rust.

Sounds like the previous owner didn't maintain the way he should have, so I would be very meticulous in going through everything."
 
"Thanks alot for everyones hel

"Thanks alot for everyones help. I had the carb rebuilt, it runs great. Turns out no gas was being fed to the left side."
 
Back
Top