NS8B problems, need advice

rhm

Recruit
Joined
May 30, 2012
Messages
2
I bought a old sailboat and it came with a ~1992 Nissan 8hp 2stroke on it. The seller said it just needed a carb rebuild. So, I took it apart and cleaned it with spray, put it back on and would start and run better, but not great. I got some stuff to soak the carb, and did overnight. It ran better when I put it back on, but a week or two later (the next time I tried) it would not start. I ordered a carb rebuild kit and resoaked the carb. After that it ran awesome. Until a week or so later it would not start so I took the carb bowl off on the spot and it had some gunk, I re-re-re-cleaned it and it worked. I got some fresh gas went out and it cranked first pull every time for a couple of days. A couple of weeks later I tried to take it out again, and it started, but kept cutting out. Today, I tried re-cleaned the carb, there was a small amount of gunk. After cleaning it, it still would not run. It will start and sound good for about 20 seconds. Then it will bog down, and not want to start for a while. If I try to lightly rev it, it bogs down. If I really rev it it will run, but bog down when I let off the gas. I took the plugs out, (i put in new ones, as soon as I got it), and they seemed fouled. I am going to try new plugs next, but what am I doing wrong with the carb?

Thanks in advance.
 

pvanv

Admiral
Joined
Apr 20, 2008
Messages
6,579
Re: NS8B problems, need advice

Clean out the entire fuel system. You are probably re-contaminating the carb after cleaning it. Flush out or replace all hoses, and get the tank spotless.
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Re: NS8B problems, need advice

Which type of gunk is it ? small white, ligh yellow micropellets ? Does gunk accumulates inmediately after fuel pump on lower bowl area ? If so, could be E fuels badly filtered at plant, gas staion bypassing tank and engine filter. If fuel line is that old, better buy a new one and clean tank and internal & external filters inmaculate clean.

Happy Boating
 

rhm

Recruit
Joined
May 30, 2012
Messages
2
Re: NS8B problems, need advice

The gunk is orange color. It is not solid, but kind of gummy.

The fuel line is new.

I just bought an water separating filter and a new tank. I read somewhere else that the ethanol in gas can scour the junk off the inside of an older tank, even if it looks clean.

Hopefully that will fix it.
 

pvanv

Admiral
Joined
Apr 20, 2008
Messages
6,579
Re: NS8B problems, need advice

Yep. Some fuels leave a stain behind. If you empty the carb, that junk won't be there to evaporate.
 
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