1993 70 nissan light backfire

[junior1113]

just got this boat. been sitting for years. i got it running good except the light mis in bottom cylinder. seems like a little smoke comes up from main gasket. bottom of lower cowling. havnt done carbs could this be the problem. p.s this is on the hose running

 

[pvanv]

Re: 1993 70 nissan light backfire

The smoke could be oil and junk burning off, or you may need a new base gasket -- where the exhaust housing bolts to the powerhead.

Prudent to go through the carbs and check everything over.

 

[TOHATSU GURU]

Re: 1993 70 nissan light backfire

Is this a 70 A or a 70 B?

 

[junior1113]

Re: 1993 70 nissan light backfire

thanks for your time NS70A2. HAVENT TOUCHED CARBS COULD THIS MAKE THESE SYMTOMS? PULLED NEW PLUGS AND BOTTOM PLUG WAS BLACK JUST FROM 10 MIN IDLE ON HOSE

 

[TOHATSU GURU]

Re: 1993 70 nissan light backfire

Carburetors can't cause a backfire, however they can cause the engine to run rich if they are not set correctly. But, you need to consider something before you go any further with this engine....It's 17 years old, they stopped making parts for it years ago and virtually nothing is available for it anymore. Be very careful with the money you spend on it as whatever you fix today will not count when something else breaks tomorrow.

 

[junior1113]

Re: 1993 70 nissan light backfire

really, just want to know what could cause this coughing (backfire).?

 

[TOHATSU GURU]

Re: 1993 70 nissan light backfire

If you have a true backfire: Broken flywheel key, bad trigger coil, bad CD module or a twisted crank....The crank and trigger coil are no longer available.

 

[junior1113]

Re: 1993 70 nissan light backfire

ok, adjusted carbs and runs perfect. lower carb low speed jet clogged. carb can make engine light backfire.

 

[TOHATSU GURU]

Re: 1993 70 nissan light backfire

Actually, a carburetor cannot cause a backfire. I think you are confusing a miss/pop with a backfire.

 

[junior1113]

Re: 1993 70 nissan light backfire

hey it was a miss/ pop sorry i worded it wrong thanks for your time though.

 

[TOHATSU GURU]

Re: 1993 70 nissan light backfire

Not a problem at all. The only reason I try to make things like that clear is because the terminology makes a difference when you try to diagnose something without being there