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1997 Merc 15hp nostart problem

T

teamguerino

New member
"I just got my first ever boat

"I just got my first ever boat & can't get the motor started. I've fiddled with lawnmower carbs and my International Scout carb some, but marine motors are new to me.

I just replaced the entire fuel system (old one was VERY old): new gas tank, fuel hose & fittings. Symptoms: flush cup attached w/ garden hose for cooling. I (now) get a firm bulb when priming the fuel line. Tank vent is open and stop switch is on RUN. I rotate the idle speed knob full on, pull the knob 3x like the book says and crank away. Usually I get nothing - engine rotates but doesn't fire. I even opened the throttle plate & shot starter fluid down the hole, but no fire.

Twice I've gotten it to idle (very roughly) for about 15 seconds. 1st time it died after that. New fuel & fuel system installed, then 2nd time I panicked a bit when I didn't see water coming out of the spit hole so I shut it off. Since then I haven't been able to get it started.

The spark plugs look fine to me. Any advice before I blindly rip the carb apart and make my life even more miserable?


Thanks

Matt"
 
"Matt:

Take a deep breath,

"Matt:

Take a deep breath, then buy a carb rebuild kit (big $$$$). No doubt the carb is full of crud that's blocking off the passages.

Jeff

PS: I assume you checked both cylinders for spark?"
 
"Yes, I would add - change the

"Yes, I would add - change the spark plugs as well and make sure you install NGK's BP8HS-15's gapped to .060" - don't cross ref to another brand (Champion etc).

That model is an outstanding little motor (I own one) and not really alot goes wrong with reasonable care.

So as Jeff suggests, rebuild the carb. If you don't mind spending about 80 bucks you can get a complete "repair kit" from Merc with everything you need to rebuild the carb, fuel pump and primer assembly - otherwise there are some aftermarket kits around (generally about 25 bucks or so) that simply have a couple gaskets and the needle valves).

Personally, I would do the whole thing. Then if you take care of it you will never touch it again.

Mine is 20 years old and the carb has never been rebuilt at all - fresh gas all the time and properly winterized equals zero problems with these Walbro carbs..."
 
"Thanks for the info gents - I

"Thanks for the info gents - I appreciate the guidance.

*sigh* not a big fan of carb rebuilding, but I'm willing to give anything a shot. I did check the plug type and it is equipped with the NGKs you mentioned, though they were gapped at .04 and .045 respectively, so I changed it. I didn't verify spark at the plug - I'll try that. Assuming It sparks while cranking, I guess I';m in for a carb rebuild..."
 
"Jeff & Graham,

Thanks

"Jeff & Graham,

Thanks for the advice. I bought a gasket and diaphragm kit (65 bones! Yikes) and taught my 12-year-old daughter how to rebuild a carburetor. She and I doused all the parts with almost 2 full cans of carb cleaner, put it all back together with the new gaskets and reinstalled. With a bit of coaxing, the motor fired up for the first time in who-knows-how-long and ran nicely for about 20 minutes! I was able to verify water pump & T-stat function as well as tune the idle mixture and idle speed before shutting it down and winterizing it. Spring should bring some good trout fishing! Thanks again."
 
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