1992 150 hp evinrude backfire rough

guyo

Petty Officer 3rd Class
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Mar 9, 2005
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81
1992 150 hp evinrude backfire rough

Only got 4300 rpm and engine hard to start, needed to be warmed up or it would stall rebuilt carbs to spec,replaced all filters and plugs /motor only ran on manual prime/ I back flushed all fuel components now engine runs :But it occasionally lets out a puff of smoke and seems to back fire// concerned about relaunching dont want to stranded at sea/<br />/ help//
 

Walker

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Jun 15, 2002
Messages
3,085
Re: 1992 150 hp evinrude backfire rough

Re: 1992 150 hp evinrude backfire rough

Test the recirculation valves.
 

guyo

Petty Officer 3rd Class
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Mar 9, 2005
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Re: 1992 150 hp evinrude backfire rough

Re: 1992 150 hp evinrude backfire rough

where are the recirculation valves, or do you mean to check fuel lines/?
 

guyo

Petty Officer 3rd Class
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Mar 9, 2005
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Re: 1992 150 hp evinrude backfire rough

Re: 1992 150 hp evinrude backfire rough

? i need to see up close part diagrams of my engine so i know how it ticks. Is there a web site that can help me. ps;I already have the seloc engine manual.
 

Dhadley

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Feb 4, 2001
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Re: 1992 150 hp evinrude backfire rough

Re: 1992 150 hp evinrude backfire rough

The puff of smoke and pop is when the raw fuel in the exhaust ignites or a cylinder thats not firing, does. While its sitting there running, pull off one plug wire at a time with plastic pliers. When you get to the cylinder(s) that nothing changes, thats the one not firing.
 

Joe Reeves

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Feb 24, 2002
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Re: 1992 150 hp evinrude backfire rough

Re: 1992 150 hp evinrude backfire rough

What is the compression.... actual psi readings of the cylinders?<br /><br />With the spark plugs removed, the spark on all cylinders should jump a 7/16" gap on all cylinders with a strong blue lightning like flame. Does it?<br /><br />If by "backfire" you mean that the engine sort of spits back at idle, and especially if the engine has been sitting for a few months or more, that is usually caused by fouled, clogged, gummed carburetors (common problem). In which case the cure is to remove, clean, and rebuild "all" of the carburetors.<br /><br />To test for a carburetor problem, remove the carburetor face plate so that you can see the carburetor throats. With the engine running, stick two (2) fingers into a carburetor throat which will act as an individual choke.<br /><br />If the problem vanishes on a particular carburetor finger test, or improves, that carburetor is faulty.<br /><br />Keep in mind that simply cleaning one carburetor would be simply transfering the problem to a later date.
 

guyo

Petty Officer 3rd Class
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Mar 9, 2005
Messages
81
Re: 1992 150 hp evinrude backfire rough

Re: 1992 150 hp evinrude backfire rough

thanks guys for the quick replies !!<br />carbs already rebuilt to specs<br />I have good spark on all 6 cyl<br />re compression all cyl 100 except top two are at 95 i think its ok within 10 percent
 
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