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east tx skier
11-07-2005, 01:10 PM
Okay, so I winterized this weekend and decided to fog my cylinders directly. Every plug appeared to be wet fouled (black and oily). After a little internetting on the subject, that would seem to indicate that I might be running rich. However, part of me is thinking that they looked like that because I had just been running my boat at idle on a bucket and had just fogged the engine through the carb. In other words, to properly read plugs, I need to run the boat at certain rpms, stop, read, rerun at different rpms, and so on.

Plugs were installed at the end of last season (will install new ones next spring). Boat has run like a top all season (except for 300 or so drop in rpms when I run it for a few seconds at 2,375 rpms). Only change has been Edelbrock performer intake installed last winter).

Was it because I'd just fogged through the carb? Was it because I'd been running only at idle? Both? Neither? Mixture too rich?

martini
11-07-2005, 01:17 PM
I would say you're on the right track with regards to an accurate reading of the plugs. I wouldn't worry about it right now, since you've winterized. Wait until next season, say mid summer, once your new plugs have been used for a while and check them then. I can't believe you've winterized already, it's 85degrees!

bigmac
11-07-2005, 02:17 PM
Okay, so I winterized this weekend and decided to fog my cylinders directly. Every plug appeared to be wet fouled (black and oily).

Was it because I'd just fogged through the carb? Was it because I'd been running only at idle? Both? Neither? Mixture too rich?

The concept of "reading the spark plugs" is a kind of slippery one. The point is to try to tell from the plugs whether or not you're running rich or lean - grey/white being lean and black/oily being rich.

The problem is that the plugs only "read" what combustion was like at the moment you shut it down. You can be rich at open throttle positions and lean in the mid range, normal everywhere else, depending on the accuracy of your carb jetting or your EFI map.

You won't learn anything important from reading the plugs after idling and fogging.

MarkP
11-07-2005, 02:28 PM
Okay

Was it because I'd just fogged through the carb?
Yes!
That is exactly what fogging is supposed to do ..

LakePirate
11-07-2005, 02:45 PM
To insert a little redneck knowledge here
In NASCAR when a guy runs a good 1st qualifying lap and is not going to attempt a second his crew chief have him kill the engine and coast back to the garage in order to get a clean read on the plugs while running at speed.

BriEOD
11-07-2005, 02:55 PM
Doug,

You're a smart guy, but have you ever heard of the concept "if it isn't broken don't fix it?" You tinker to much man. Remember your spring on the throttle.

Leave it alone!!

AirJunky
11-07-2005, 03:01 PM
How do you fog thru the carb? I thought the only way was thru the plug holes.

88 PS190
11-07-2005, 03:16 PM
W/ the engine running and the spark arrestor off you spray fogging oil down the carb throat until the engine stalls.

Then its fogged. No problems.

east tx skier
11-07-2005, 03:20 PM
Thanks for the responses.

Martin, I know. It's warm. Got a sister-in-law about to have her 3rd baby. Will be out of town visiting them. If it is still warm after Thanksgiving, I may recomission for a run.

Brian, wasn't looking for anything, just had them out and thought I would ask. And yes, I'm smart. ;)

Okay, I feel better.

east tx skier
11-07-2005, 03:21 PM
Thanks for the responses.

Martin, I know. It's warm. Got a sister-in-law about to have her 3rd baby. Will be out of town visiting them. If it is still warm after Thanksgiving, I may recomission for a run.

Brian, wasn't looking for anything, just had them out and thought I would ask. And yes, I'm smart. ;)

Bill, what 88 190 said.

Okay, I feel better.

P.S. Anybody have any tips on a better way to get at that port-side plug (3rd one back) on the 351W. :rant:

JimN
11-07-2005, 03:33 PM
Doug- don't try to read the plugs unless the motor has been run to normal operating temperarure, under normal use. After fogging, all you can tell is that the fogging oil got into the cylinders.

Regarding the spark plugs and getting them out, if you're using a ratchet and socket, try a box wrench. Once they loosen, you should be able to slide an old plug wire boot (the straight kind) onto it and back it out. If you have an old plug or coil wire, clip the wire off so it's about 3" long and it'll let you remove the plugs even when they're smokin' hot.

east tx skier
11-07-2005, 03:50 PM
Thanks, Jim. I should've mentioned that I always use a box wrench. I'll be swapping the wires in the spring and will save a couple of boots so I can get that thing turning easier.

88 PS190
11-07-2005, 05:05 PM
Box wrench and a bit of vac. tube line or fuel line available at napa etc. I know an old plug wire would work but its just as easy to get a bit of hose at napa or the hardware store, then you can just spin them out. You can start plugs with it too, but be sure not to crossthread.

A marina I used to work at would grind the metal back on the exaust manifolds so that the plugs could be easier to remove/access, but I do not endorse that unless you remove the manifolds and ensure you do not over thin the manifold.

east tx skier
11-07-2005, 06:24 PM
Good deal. On that one plug, the box wrench is a very tight fit. Chevy makes it much easier. Thanks for the tips.

88 PS190
11-07-2005, 07:14 PM
Its far worse on I/O's and V drives. DD leave you a nice place to lay down and get in there. Esp. if you remove the engine cover.

Hoff1
11-08-2005, 07:54 AM
Doug, here's my method of extracting spark plugs. Works very well. Mine was a so tight that a box wrench wouldn't seat over the plugs, so I needed an inch or two extension, but a full socket would be too much. It took me about 10 minutes to modify the tool.

http://www.tmcowners.com/teamtalk/showthread.php?t=2461&highlight=spark+plug+drill

MYMC
11-08-2005, 10:05 AM
Doug,
As said before in this thread don't bother with the "plug check". After doing thousands of these I can tell you it takes a while to learn what to look for and how to correct it. Also when we did these the car had run with the throttle wide open down the longest straight at which time the driver would kill the engine and knock the trans into neutral...if he missed neutral it usually hit the wall. This is the only way to get a "clean reading". Also the "plug check" worked and was easy in the days of leaded race fuel...unleaded fuel burns much differently and is much harder to "read".

The best way to check fuel/air is to have someone come on board with a Horiba fuel air analyzer (which will require a modified exhaust manifold) and map the exhaust while you drive. This could also be done if you put the engine on a dyno that is properly equipped.

east tx skier
11-08-2005, 12:43 PM
Thanks, all.