460 tune up question

[Bkhitech]

Hi,
My Brother purchased a 1988 Chris Craft 312 sting with twin OMC 460 engines. It has been a while since I have been playing around with engines and while checking the spark plug conditions I found the gap to be more close to .045 on most of the plugs. Manual calls for .035". Stock motor raft coils still installed and still using points. Any reason someone may have increased the gap to 045 other than they just bout plugs and never checked the gaps?
thanks for anyone's help in advance.
BK

 

[alldodge]

Many will change the gap setting thinking it may help an issue they were having or may even think this would increase performance. Could be they bought plugs that were already gaped at .045 and didn't check.

 

[kenny nunez]

Do like AD said on the plugs. Change the points to a Petronics electronic system.
Obtain a set of genuine Holley gasket sets. Over time the gaskets under the metering blocks tend to shrink and the small passages for fuel and air get compromised resulting in a rough idle and flooding. The idle mixture screws should always be near 1.5 turns from seat. Any time that changes is a signal to replace the gaskets.
Next to fuel injection a Holley is the most responsive of all the carburetors I have worked on.
Needless to say, stay away from any Ethanol added fuel.

 

[HT32BSX115]

Hi,
My Brother purchased a 1988 Chris Craft 312 sting with twin OMC 460 engines. ...................Any reason someone may have increased the gap to 045 other than they just bout plugs and never checked the gaps?
thanks for anyone's help in advance.
BK

Howdy BK Welcome aboard!

I wouldn't worry about why the plugs are gapped wrong. Just gap them correctly and move on.

It's of the utmost importance to check those drives carefully for alignment and do a drain and refill of the drive oil if it has NOT already been done.

If someone else did it, be sure to check the oil levels and if it has not been run since drive-oil change, either make sure whom ever changed it either did it correctly or drain and refill them again (IAW the OEM OMC manual.......NOT CLYMER NOT SELOC and NOT according to your pet Volvo mechanic etc) Filling those drives wrong will destroy them (and they're fast becoming NON-replaceable)

Do like AD said on the plugs. Change the points to a Petronics electronic system.
Obtain a set of genuine Holley gasket sets. ////////////
///////////
Needless to say, stay away from any Ethanol added fuel.

I would agree on switching to Pertronics.......good system etc.......except, I (and my brother who bought my [formerly]460 powered boat new) NEVER had an ignition problem (1987-2005) with the original distributor with points.

I disagree on the ethanol fuel.

That's all my 460 ever got from new and it's all I use now with the newer (1997 carbureted) Mercruiser 7.4L V-8.

I just put the boat away with as little gas in the tank as possible so I can fill it up with fresh fuel at the beginning of the next boating season. (fuel tank condensation is still a myth by the way)


Cheers,

Rick