Whaler Central - Boston Whaler Boat Information and Photos

Posted by MCathcart on 05/07/11 - 7:17 AM

I came here expecting numerous threads with people having carb problems from the 10% ethanol gas. My 2003 40 Mercury has turned into a PIA since last year. I pulled and cleaned the carb last year and this year I've ran it maybe 5 hours and it's back to running like Crap again. I'm at the point to where I'm considering a new 4 Stroke OB. (13' Boston Whaler Sport) My '03 engine still runs like a Champ when the carb is nice and clean but one little spec of trash and it's floods, won't idle, pops and fouls plugs.

Guess I'll pull the carb off and hunt for that Turd in there somewhere.

Also... What Spark Plugs Are You Having The Best Luck With? I've always used NKG's in anything that was a 2 Stroke with good luck. Another idea I'm pondering is going up one heat range to see if that will help.

Thanks!

Posted by Tom W Clark on 05/07/11 - 8:23 AM

Cleaning the carburetor is good but you should inspect and, if necessary, clean your fuel tank and perhaps replace your fuel line and filter.

What type of fuel tank you use?

What type of fuel line you use?

Posted by MCathcart on 05/07/11 - 10:05 AM

I have a Mercury filter-separator cartridge (and the second Mercury filter on the engine). Gas line is the original gray. I got some new gas line last week.

I went to the boat and pulled the carb off this morning (it stays in the marina). Going to open it up again and clean it right now. I'm surprised that anything gets in the carb that will cause a problem since the filter mesh on the engine is so small.

Posted by Derwd24 on 05/07/11 - 11:47 AM

Check the integrity of the fuel lines on the engine too, sometimes these can degrade and be the source of the particulates that end up clogging the carb passages.

Posted by MCathcart on 05/07/11 - 2:24 PM

The carb was spotless! Must be in the fuel or electrical. I have found that looking up plugs NGK shows two types.

NGK BP8H-N-10
*NGK BPZ8H-N-10
0.040 in. (1.0mm)

*Suppressor (resistor) spark plug

It has the BP8H-N-10 plugs. Looking at the side of the engine yesterday the Mercury tag says BPZ8H-N-10's. On NGK's site they warn about running the Non-resistor plugs in a CDI ignition that they'll start to fail at idle etc. I ordered 2 sets of BPZ's to try.