* NEVER underestimate the value of a GOOD distributor cap ( major tuning event )

* NEVER underestimate the value of a GOOD distributor cap ( major tuning event )

Paul
Paul

June 2nd, 2008, 2:07 am #1

Well I had a major 427 tuning event this afternoon that I want to pass on to everyone, because sooner or later you'll all have the same issue to tend to.

I'm going to be taking a boat load of business associates on a river cruise to dinner later this week, and I wanted to be sure I looked at everything before hand to be sure I had a safe and fun night time run back down the Cumberland River. I changed out the belt on the port sea water pump, which was a joy.

For anyone interested in how this is best done, you remove the 4 bolts in the water pump pulley, pull that off, change out the belt, put the pulley back in place, and force it onto the hub wher you can get at least one bolt in place. The rest is cough, cough, relatively easy from there, lol. Everything is relative when you're standing on your head. Be sure to have a bright fluorescent trouble light down there where you can see everything.

Then I sprayed the big dogs down with Gibbs Brand, wiped everything down, and they looked grand. After a clean up I started both motors and did a basic carb check. All was well.

Janet showed up with pizza, and I took a break before cleaning up all my tools, etc. We sat there and had a couple beers, ate pizza, and it was quite relaxing. As we were getting ready to depart, I decided to fire up both engines and listen for a moment. The Starboard motor that recently got the rebuilt carb fired up instantly. The Port motor started slowly and then it stumbled GREATLY every time I tried to give it a little throttle. As I gave it more throttle, it just went BLAHHHHHHHH, BLAHHHHHHHHHHHH, and it would not even rev. It popped a bit, and although it would idle well, it wouldn't rev at all.

So here I am at the end of the day, with a blankety-blank mechanical problem right ahead of a major cruise with a boat load of people. Crap !

So I did what I would recomment to any of you with the same problem. I swapped carbs. That was easy. All that is needed to swap carbs is the following: a 11/16 open box wrench, a 9/16 open box wrench, a 7/16 open box wrench, a screwdriver, and a needlenose pliers to pull the cotter key from the throttle drive shaft.

Janet sat there and watched me pull the Port carb, sit it on the pizza box, pull the starboard carb and install it. Once installed, I tried to start the starboard motor again, and BLAAAAHHHHHHHH, pop, pop. NOTHING. I looked at here and said, "well, it's not the carb". She said, "but you don't know what it is". I said, "yes that's right, but I do know it's not the carb".

Then I popped the distributor cap and took a look. To my surprise, there were some pretty serious burn marks. What is quite amazing, is LAST WEEK we ran the TRADITION at wide open throttle down the river and it ran well. Today with no warning at all, the starboard motor would barely start. I went to my forward cabinet where I keep the spare parts, pulled out a new crab cap and transposed the wires. I re-installed the cap and wondered if it would make a difference.

Guess what?

VARRRRoooooooooooMMMMMMMMMM, instantly! Yes indeed. Never underestimate the value of a good cap.

These things are out of sight and out of mind. Most of the time we don't even know they're there. However, they do have a life span. They are a consumable part. They MUST be replaced when they get some wear on them, and quite honestly I don't think I got all that many hours out of this one.

I took some close up photos of the carbon tracks and burn marks, and I'll upload these in a little while to go along with this thread.

Cheers! A little preventative maintenance hopefully kept me from having an embarassing and potentially dangerous evening on the water!

Regards,

Paul

FXA 38 3004 R
1966 38' Express
Original 427 power
Last edited by FEfinaticP on May 15th, 2012, 9:59 pm, edited 1 time in total.
Quote
Share

Paul
Paul

June 2nd, 2008, 2:56 am #2

This is a classic.

Motor was running reasonably well last time out. This time, BLAHHHHHHHH, didn't even want to rev past 2000. My initial thought was dirt in the main carb jets.

Well......here is the culprit.



These photos are exactly as the cap came off the motor.









I pay so much attention to other issues, this was clearly overlooked. I should have been checking the caps. Believe me, from now on I will check them carefully and on a regular basis.

I am still pretty stunned at the difference replacing the cap made. It went from "won't start", to VARRRrrrrooooOOOOOOOOMMMMMMMMM. Today was very humid, and I think that is what brought on the issue like it did.

Regards,

Paul







Quote
Share

Paul
Paul

June 2nd, 2008, 3:07 am #3

Well I had a major 427 tuning event this afternoon that I want to pass on to everyone, because sooner or later you'll all have the same issue to tend to.

I'm going to be taking a boat load of business associates on a river cruise to dinner later this week, and I wanted to be sure I looked at everything before hand to be sure I had a safe and fun night time run back down the Cumberland River. I changed out the belt on the port sea water pump, which was a joy.

For anyone interested in how this is best done, you remove the 4 bolts in the water pump pulley, pull that off, change out the belt, put the pulley back in place, and force it onto the hub wher you can get at least one bolt in place. The rest is cough, cough, relatively easy from there, lol. Everything is relative when you're standing on your head. Be sure to have a bright fluorescent trouble light down there where you can see everything.

Then I sprayed the big dogs down with Gibbs Brand, wiped everything down, and they looked grand. After a clean up I started both motors and did a basic carb check. All was well.

Janet showed up with pizza, and I took a break before cleaning up all my tools, etc. We sat there and had a couple beers, ate pizza, and it was quite relaxing. As we were getting ready to depart, I decided to fire up both engines and listen for a moment. The Starboard motor that recently got the rebuilt carb fired up instantly. The Port motor started slowly and then it stumbled GREATLY every time I tried to give it a little throttle. As I gave it more throttle, it just went BLAHHHHHHHH, BLAHHHHHHHHHHHH, and it would not even rev. It popped a bit, and although it would idle well, it wouldn't rev at all.

So here I am at the end of the day, with a blankety-blank mechanical problem right ahead of a major cruise with a boat load of people. Crap !

So I did what I would recomment to any of you with the same problem. I swapped carbs. That was easy. All that is needed to swap carbs is the following: a 11/16 open box wrench, a 9/16 open box wrench, a 7/16 open box wrench, a screwdriver, and a needlenose pliers to pull the cotter key from the throttle drive shaft.

Janet sat there and watched me pull the Port carb, sit it on the pizza box, pull the starboard carb and install it. Once installed, I tried to start the starboard motor again, and BLAAAAHHHHHHHH, pop, pop. NOTHING. I looked at here and said, "well, it's not the carb". She said, "but you don't know what it is". I said, "yes that's right, but I do know it's not the carb".

Then I popped the distributor cap and took a look. To my surprise, there were some pretty serious burn marks. What is quite amazing, is LAST WEEK we ran the TRADITION at wide open throttle down the river and it ran well. Today with no warning at all, the starboard motor would barely start. I went to my forward cabinet where I keep the spare parts, pulled out a new crab cap and transposed the wires. I re-installed the cap and wondered if it would make a difference.

Guess what?

VARRRRoooooooooooMMMMMMMMMM, instantly! Yes indeed. Never underestimate the value of a good cap.

These things are out of sight and out of mind. Most of the time we don't even know they're there. However, they do have a life span. They are a consumable part. They MUST be replaced when they get some wear on them, and quite honestly I don't think I got all that many hours out of this one.

I took some close up photos of the carbon tracks and burn marks, and I'll upload these in a little while to go along with this thread.

Cheers! A little preventative maintenance hopefully kept me from having an embarassing and potentially dangerous evening on the water!

Regards,

Paul

FXA 38 3004 R
1966 38' Express
Original 427 power
Here are a few photos of TRADITION, our 1966 38' Express, FXA-38-3004-R, powered by 427 big dogs.

When they're running well, they're a joy. They run well most of the time, but like all motors, they do need some attention now and then. Don't overlook those distributor caps!

There she sits. My place of refuge when I need to get away, when we want to entertain friends, when Janet and I want to get away for total privacy and fun. There is nothing quite like a classic Commander. Everyone at the yacht club knows this boat, and they also know how fast she is too!




Just over top of the flybridge in this photo is the LADY J, Alan Jackson's 70' immaculate Berger. It recently arrived back at the harbor, after spending time somewhere in Florida.


Our quiet little harbor is one of the better kept secrets in Nashville. It's a private club, and it's a great place to keep a cruiser. Little did I know, after this photo was taken, I would be down there swapping carbs and distributor caps, lol. Ah well, that's boating. If everything always went well, we would have to call it something else.

Regards,

Paul






Quote
Share

Joined: December 21st, 2006, 1:10 am

June 2nd, 2008, 12:32 pm #4

This is a classic.

Motor was running reasonably well last time out. This time, BLAHHHHHHHH, didn't even want to rev past 2000. My initial thought was dirt in the main carb jets.

Well......here is the culprit.



These photos are exactly as the cap came off the motor.









I pay so much attention to other issues, this was clearly overlooked. I should have been checking the caps. Believe me, from now on I will check them carefully and on a regular basis.

I am still pretty stunned at the difference replacing the cap made. It went from "won't start", to VARRRrrrrooooOOOOOOOOMMMMMMMMM. Today was very humid, and I think that is what brought on the issue like it did.

Regards,

Paul






Looks like there is some physical damage in that cap..rotor has struck the terminals. If the cap wasn't seated perfectly this can occur.

Caps are a MAJOR problem on late model chevies that use the flat top cap like yours. In their case, the conductors are molded into the cap from one side to the other.
Quote
Like
Share

Steve
Steve

June 2nd, 2008, 1:14 pm #5

This is a classic.

Motor was running reasonably well last time out. This time, BLAHHHHHHHH, didn't even want to rev past 2000. My initial thought was dirt in the main carb jets.

Well......here is the culprit.



These photos are exactly as the cap came off the motor.









I pay so much attention to other issues, this was clearly overlooked. I should have been checking the caps. Believe me, from now on I will check them carefully and on a regular basis.

I am still pretty stunned at the difference replacing the cap made. It went from "won't start", to VARRRrrrrooooOOOOOOOOMMMMMMMMM. Today was very humid, and I think that is what brought on the issue like it did.

Regards,

Paul






Been there and done that one and now thats one of the first things I look at whenever the motors start to act up or if they happen to stall out in the middle of a channel and I have to put the boat in someone else's slip temporarily......
Also, great photo's of your boat Paul!
Steve
1969 42'Commander
Bear Z Girl
Quote
Share

Paul
Paul

June 2nd, 2008, 2:21 pm #6

Looks like there is some physical damage in that cap..rotor has struck the terminals. If the cap wasn't seated perfectly this can occur.

Caps are a MAJOR problem on late model chevies that use the flat top cap like yours. In their case, the conductors are molded into the cap from one side to the other.
Hi Bill,

Always appreciate your comments and perspective on things. I looked at the rotor and there was no apparant damage to it. Although there appears to be some plastic shedding at the internal terminals of that bad cap, I don't think there was an actual physical contact. I'm normally much more careful than that, but as noted, if the rotor and cap don't match up, being careful really doesn't help because they are going to rub or strike.

I got two freshly rebuilt distributors back from Mallory several years ago, with caps, rotors, etc., and when I put the caps on, the darn rotor struck the underside of the cap.

Upon discussing this with Mark Weller one evening, Mark said there are three types of crab caps, maybe more.

I actually have three different types aboard TRADITION now.

I have the black one on my Starboard motor, I just took a creme colored one off the Port motor and put a new one just like it on that motor and everything works great, and then I have some old red ones.

The creme colored version I just installed does not have a gasket under it.

The red ones DO have a gasket, and Mark was mentioning the gasket to me during a conversation about how these caps fit.

The black one I do not think has a gasket, but I will check.



Natually, I have some spares aboard the boat like eveyone else does. One of my spare red caps has a note taped to the underside that says, "ran well, but with a slight miss". That one will be able to get me home some day, but that's about it.

The interesting thing about the internal contacts in these crab caps, they look like rods that are coming in from the side, and they are ground off accordingly. Some of the contacts are dead-on-perpendicular to the outside of the cap, and some of them come in at an oblique angle, and those look like they have been hit and lodged out of alignment.

After seeing the condition of my bad cap, does this look like I'm running a coil too hot, bad timing, whatever, or is this just the normal life of a crab cap?

One thing for sure. Anyone running a classic boat with these caps, would do well to keep a couple spares aboard. If mine went sour so fast, it can happen to you to, and it is hard to know the condition of these caps unless you LOOK at them from time to time. If you see carbon tracks building up, better get a spare ready!
Quote
Share

Joined: December 21st, 2006, 1:10 am

June 2nd, 2008, 4:16 pm #7

Thanks, Paul. After looking at the firing patterns, it appears you MAY have a spark inaccuracy problem. Some terminals appear to be firing at the side of the terminal, due to early or late spark (timing). This can be caused by sloppy distributor bushings, bent shaft in distributor, worn lobes on the points, or misplaced magnets on the reluctor ring if its pertronix.

I'd put a timing tape on the damper, and make sure EACH cylinder is firing when it should. If #1 is 20 degrees at 2000 rpms, ALL should read 20 degrees at 2000 rpms. A v8 fires every 90 degrees of crankshaft rotation. For instance, 2 cylinders fire at TDC, just 1 revolution apart. A distributor machine will diagnose this also..and I just happen to have a distributor machine, if you can't find one near you.

A coil only makes as much voltage as is necessary to fire at a particular time. A cylinder under load/high combustion chamber pressure requires more voltage for the spark to jump the gap than a lightly loaded cylinder, say at idle. The old English car trick to clean a fouled plug..hold the wire away from the cap. The greater distance requires more voltage to jump, thus a hotter spark at the plug. Same with resistor plugs and wires. So no, the coil is a non-issue in this case.

Thoughts???
Quote
Like
Share

Paul
Paul

June 2nd, 2008, 4:43 pm #8

Just doing a quick confirmation on the timing would be a start. That motor has not been touched in recent days. The other motor has gotten all the attention. Both of them fired up with a vengence last night after all the attention was given. I'm ready to rumble, but I will most certainly do a timing check on both motors as soon as I can. When they're set right, they sure do work well.

Many thanks for the comments. I doubt if I have a work distributor, as both were totally rebuilt at Mallory a few years ago. I suppose they could stand some preventative lubrication, maybe I should remove the top plate and take a look?

One other thing, funny as it is, on the rebuilt carb the idle adjustment screws don't appear to do anything at all. I plan on using that carb, which is presently performing well, as a spare. I will rebuilt the two carbs that were on the boat sometime in the next few weeks and use those. The recently rebuilt carb came off a spare motor I have stashed away.

Hey, we're having some fun now! ?

Regards,

Paul
Quote
Share

John Kloka
John Kloka

June 2nd, 2008, 8:29 pm #9

Been there and done that one and now thats one of the first things I look at whenever the motors start to act up or if they happen to stall out in the middle of a channel and I have to put the boat in someone else's slip temporarily......
Also, great photo's of your boat Paul!
Steve
1969 42'Commander
Bear Z Girl
As our friend and skipper of the Beer-Z-Girl so gracefully alluded... the li'l Klokanuts left me hangin in a 20 knot breeze over the weekend...

I was bringin' the ol' girl to her home dock at MacRay Harbor, the lake was seriously chopped up, when I brought her into the canal and throttled back, she stalled out and would not re-start! The wind blew me towards the rip-rap sea wall, but a good samaritan on shore was able to grab a line I tossed, and between the line to shore and some fancy gaff-hook antics, we were able to get her into a well at the mouth of the harbor entrance. After several attempts at re-starting, inspecting the fuel delivery, etc... who should come motoring up in his dinghy? My old buddy Steve! He saw me come into the harbor and was coming to say "Hi".
Anyway... the carb was squirting fuel alright, but the darn thing acted like the timing was way off. Checked distributor, not loose. Checked coil, hot to the touch. I'm thinking coil or condenser issue. I just picked up a Petronix Ignitor setup to eliminate the points and coil because I HATE points...
It was in the truck back at the dock! I was gonna change it over on Sunday.
So, I ended up calling for a tow-boat to ge her back to my well because the wind was getting worse and I did not want to die mid-canal again!
I'll be elbows deep in that dang distributor later this week, that's for sure!
And thanks, Steve, for not spilling the beans... did I mention the tow-boat skipper was a girl??

John Kloka
Quote
Share

Paul
Paul

June 2nd, 2008, 9:00 pm #10

Hi John,

I experienced a similar issue with my 1966 Skiff and the 327F+

We were motoring along, throttled back to get a slow speed, motor stalled, would not start for an hour.

I had to twist the distributor clockwise to a position where she wanted to start, and finally she did.

Now back at the ranch I tried the same thing. Motor cranked and cranked, no start. I then installed a hot coil I had sitting around waiting for action on another boat. I hit the ignition one time and BLAAAMMMMMMM she fired right up with authority.

Check that distributor cap. Check da coil too.

While you're at it, check the condenser.

Regards,

Paul
Quote
Share