Nissan NS8b gving me fits

[dcdunbar]

I love this engine...

However, I have cleaned the carb three times, new fuel twice, new fuel filter, new plugs and same problem. I think I'm down to the fuel diaphram but not sure....

The engine starts ok- not as good as it used to before all this happened. But, now everytime I run it for about 20 15 minutes it dies. Can be running along at 1/2 throttle and then nothing. I can usually start it but it then will only run at a high rpm. If I pull the choke out it seems to run better after it dies but still this has got to be fuel related right? Not sure where to turn on this. I clean the carb again- soak for 3 hrs or overnight in carb cleaner and then blow out w. air compressor. I am looking for suggestions on this one though. BTW, what is the compression supposed to be on these engines- i could check that but dont necessarily think that it is the problem.

Many thanks
dave

 

[Sea Rider]

Re: Nissan NS8b gving me fits

How old or new is that engine ? When engine is about to die after 15-20 min run, prime fuel bulb again, if engine catches rpm, its a fuel pump related issue, usually bad diaphragams. Check condition/replace. Also could have faulty connector o'rings, letting air in and engine missing.

Depending on it's age, could be a faulty worn, dried up head gasket, idles good, when giving juice to engine problems starts. Gasket has lost it's perfect seal, worst at medium to full wot.

Happy Boating

 

[pvanv]

Re: Nissan NS8b gving me fits

Could also be a thermally-reacting ignition part... actually could be almost anything. You must diagnose, rather than guess. If priming the bulb helps, it's a lack of fuel delivery, which is likely a pump issue.