Carbon in cap/roter
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=11645
Printed Date: September-29-2024 at 1:31pm
Topic: Carbon in cap/roter
Posted By: 79Tique
Subject: Carbon in cap/roter
Date Posted: August-20-2008 at 5:50pm
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My 94 Nautique, with PCM 351, carb, electronic ignition is getting black carbon on the contacts in the distributer cap and on the rotor contacts. This causes the boat to loose power and increase gas consumption a lot. This happens about every 40 to 50 running hours.
I've replaced the coil, plugs, cap and rotor. The plug wires are the original PCM wires. They look clean on the out side and seem to attach solid. The motor runs good at idle and at speed for about 45 hours then still runs smooth just looses power and drinks gas. When it does this I scrape off the contacts in the dist cap and it runs good again. What's causing the black carbon. I'm thinking resistance on the plug wires? ------------- Work to live, not live to work. |
Replies:
Posted By: 74SkiNautique
Date Posted: August-20-2008 at 6:01pm
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On my 74, with the pcm 351, I too had black crabon in my cap, i found that it led to the plug wires arking inside the cap. I would change your plug wires to see if that fixes it. ------------- 74SkiNautique |
Posted By: 79Tique
Date Posted: August-20-2008 at 6:06pm
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Yeh,
I'm going to replace the plug wires today. I hope that's the issue, but if there is something els I should check please let me know while I'm in there. ------------- Work to live, not live to work. |
Posted By: 79nautique
Date Posted: August-20-2008 at 6:11pm
good luck with that let me know when it doesn't work. Also get a new cap and rotor made by a quality manufacturer like "Standard Electric" replacing the wires won't hurt any as it sound like they are quite old to start with but this will have no effect on the carbon tracks. You have excess moisture in the cap, a cheap cap/cracked cap or a really weak spark. are you saying that the carbon is about the center area where the carbon button in the cap makes contact with the center of the rotor? or are you talking about the tower contacts where the tip of the rotor meets the individual contacts for each spark plug wire? also are you getting the rotor seated completely? the only source is the carbon ball or arcing at the terminals, so if it is in the center and the rotor isn't seated all of the way it will apply excess pressure to the button and make it ware quicker than normal. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
79Tique wrote:Posted By: 79Tique
Date Posted: August-20-2008 at 6:26pm
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The carbon is where the rotor meets the contacts to the plug wires. Mainly on the end of the rotor. I have changed the cap and rotor a couple of times with different brands and it still happens. I agree about the weak spark, that's why I replaced the coil.
The inside of the cap seems very dry, no signs of corrosion or moisture. ------------- Work to live, not live to work. |
Posted By: 79Tique
Date Posted: August-21-2008 at 12:11am
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Some one suggested timing. Anyone know if that could cause this? ------------- Work to live, not live to work. |
Posted By: 79nautique
Date Posted: August-21-2008 at 11:04am
yes if it is too far one way or the other then when it does arc/fire it's at the very tips of the terminal and rotor segment and would be prone to leaving tracks beside the terminals. Also What plugs are you using they will effect resistance more than anything in the system. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: behindpropeller
Date Posted: August-22-2008 at 12:57am
Where do we buy "standard electric" parts??? ------------- |
Posted By: 79Tique
Date Posted: August-22-2008 at 3:59am
To adjust timing on the lake: Have my wife drive the boat WOT and I'll turn the distributer until we reach the fastest engine speed and then back it off to witch direction just a bit? Only kind of joking.  ------------- Work to live, not live to work. |
Posted By: 79nautique
Date Posted: August-22-2008 at 11:10am
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NAPA used to carry them just have to ask for it. But use a quality part not the cheapist thing you can find atleast for the cap and rotor, wires no big deal you just replace them sooner. But spend the extra couple of bucks and get the good stuff. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: 79Tique
Date Posted: August-25-2008 at 2:36am
I was running NGK's but just replaced them with Auto lite's. Also I replaced the old 7mm PCM plug wires with a new set of Taylor 8mm and noticed a big performance increase. I think maybe the wire from the coil to the cap was the main issue. I guess I won't know for about 50 more running if the carbon problem is gone. With the change in engine tone and power increase I bet it's fixed. ------------- Work to live, not live to work. |
Posted By: 79nautique
Date Posted: August-25-2008 at 11:31am
if you just cleaned the contacts in the cap and the carbon tracks and didn't replace the cap and rotor when you changed the plugs and wires then you WILL HAVE THE EXACT SAME PROBLEM within hours not after 50, so replace them and you won't have to worry about them for maybe 150 hours provided the timing is set correctly. once the tracks are in the cap they are always in the cap and you will never ever be able to clean it well enough to prevent them from coming back because it's burned into the plastic of the cap and returns quite quickly. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: 79Tique
Date Posted: August-25-2008 at 2:21pm
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I did replace the cap and rotor. Sorry I forgot to mention it as it was the first thing I did when I got home from the lake.
79 Nautique,do you have a brand of spark plug you prefer? ------------- Work to live, not live to work. |
Posted By: 79nautique
Date Posted: August-25-2008 at 3:25pm
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use autolite you don't have a foreign motor you have an american motor that requires america speced plugs. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: 79Tique
Date Posted: August-25-2008 at 7:18pm
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All my mechanical experience prior to the Correct Crafts is on European cars and diesels. On the EU stuff the none of the European plugs run as good as a NGK so I just carried that over to the boat.
The Autolite's do seem to run better. I'll stick with them I guess. I like the price better as well: $6.70 for eight Autolite plugs v/$26.00 for eight NGK's. ------------- Work to live, not live to work. |
Posted By: 79nautique
Date Posted: August-26-2008 at 10:43am
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just be sure and replace the plugs each year or they will rust in place, they do make a platinum series that are made with stainless steel and a marine series too I belive that are SS as well and those you do not have to worry about, so say use never seze on the std plugs but I never did just replaced them a lot. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: 79Tique
Date Posted: August-26-2008 at 11:00pm
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I replace my plugs every spring. They always look pretty bad after winterizing. ------------- Work to live, not live to work. |
Posted By: 79nautique
Date Posted: August-27-2008 at 11:50am
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I would always leave the old ones in for the first tank of gas before replacing them in the spring no need to feed new plugs junk, let the old plugs take it then install the new ones after the bad gas and fogging oil is burned off. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: 74SkiNautique
Date Posted: August-28-2008 at 12:36am
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I put the Autolites in mine this year, doing great. If your plaugs are fouling, something is not right. I left my champions in for 3 years, took them out to replace and almost nothing on them! Either you have a week spark, or the fuel mixture is too rich. id go with the Autolites b/c they cant rust like Champions. ------------- 74SkiNautique |
Posted By: 74SkiNautique
Date Posted: August-30-2008 at 3:43am
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Should i use the engine fog? I just remove my water pump, drain the engine block and manifolds, then refill with antifreeze. Also i drain the float bowls to keep the floats from getting stuck open. ------------- 74SkiNautique |
Posted By: 8122pbrainard
Date Posted: August-30-2008 at 8:27am
Always a good practice, This is why Chris recommended above using the old plugs in spring to burn off the fogging oil. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: horkn
Date Posted: September-07-2008 at 2:05am
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wow.
One can use NGK or autolites, or any brand as long as you keep all 8 the same brand. Then again on my jeep forum I hear folks say you can ONLY use champion copper plugs because that is what they come with from the factory. LOL. 90k later on my Bosch Platinums and I still laugh. German plugs on a 100% american 4.0 I6? Or how about Champion (american) plugs in a japanese fuji snowmobile motor. anyway.... 74, you remove your water pump? do you mean the RWP, or the engine circulating WP? I do neither, but I replace the RWP impeller when needed. ------------- 78 martinique- refloored, reinforced, stringers re glassed, re engineered interior GT40P heads Edelbrock Performer intake acme 4 blade http://img.photobucket.com/albums/v64/horkn/fish/nautique.jpg |