Help with 98 merc carb basics

[kaw550]

I had trouble with my engine. It would ocasionally run rough then stall. This went on for a couple of weeks.

Now it does it whenever I idle. It will start to run rough. If I try to accelerate it will run rough then stall. It seems to be flooding.

Is there a mixture adjustment I can use to try and lean out the mixture? I took a quick look and didnt find anything on the carb.

I couldn't find the fuel filters either.


I also plan on changing the plugs, cap and rotor this weekend.

 

[kaw550]

Re: Help with 98 merc carb basics

I forgot to add that it is a 4.3 liter.

 

[Don S]

Re: Help with 98 merc carb basics

Do the full tuneup, get your timing set, then worry about the mixture adjustment.
You will also have to put the distributor into base timing to set the timing and adjust idle mixture. I suspect you have the Thunderbolt V ignition.
Your problem could also be water in the carb. When was the last time the fuel filter was changed?

 

[kaw550]

Re: Help with 98 merc carb basics

Do the full tuneup, get your timing set, then worry about the mixture adjustment.
You will also have to put the distributor into base timing to set the timing and adjust idle mixture. I suspect you have the Thunderbolt V ignition.
Your problem could also be water in the carb. When was the last time the fuel filter was changed?

I am not sure when it was changed. Is the water seperator the same as the filter? Any idea what the timing specs are?

I have had the boat 5 years and have only changed the oil. I know jetski's, snowmobiles and am pretty good with car engines but I dont know a thing about boats.

 

[Don S]

Re: Help with 98 merc carb basics

I have had the boat 5 years and have only changed the oil. I know jetski's, snowmobiles and am pretty good with car engines but I dont know a thing about boats.

Sure hope you take better care of the other toys than you do your boat.
You are WAY past a lot of the preventive maintenance items and went straight to "It Won't Run"
Here's a link to a 2001 owners manual. It's almost identical to what a 98 or 97 would be. Have a read so you understand what all you need to do before you take it out again.
Things like pulling the outdrive, changing the impeller, tuneups, gear lube, lubing things. Filters You name it.
It's a bit over 1MB so let it load.

http://www.boatfix.com/merc/Owner/gas/86017101.pdf

 

[kaw550]

Re: Help with 98 merc carb basics

Ha, I have only changed the oil. I have had everything else done at a shop.


Thanks for the link to the manual