I am STUMPED! please HELP!

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chiefcatchemall

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Re: I am STUMPED! please HELP!

Might be a dumb question but why would timing cause my plugs to go black?
 
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chiefcatchemall

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Re: I am STUMPED! please HELP!

Well I have some very bad news guys...I went to put my new head gasket on and I looked at my piston heads and they are BLACK again. This is only after running it for about 5 mins in a can...Does this mean my rings are shot? I shouldnt have taken his word for the compression...Not very happy about it. I have replaced the magneto, rebuilt the fuel pump and carb, and did a lot of other work to it. There is no turning back now...Any ideas what it will set me back?..and where I can get these parts?...the cyl walls look in good shape..


This doesnt make me happy, but its good in a way. I have really started to learn this outboard, and I am assuming after new pistons, and rings and everything it should be like a newer motor. Lesson learned here is to not take anybody's word!!!
 
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scuba_redneck

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Feb 2, 2012
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Re: I am STUMPED! please HELP!

Quick question- when you cleaned your carb, did you replace the packing around the slow speed adjustment needle? Carb cleaner has a nasty habit of destroying any plastics it touches. I had one that refused to idle and when I went over it I realized that there was air leaking past the needle severely leaning out my air-fuel ratio and causing an extremely poor idle and run. The plastic needle seat that was in there previously had been completely dissolved by the carb cleaner. Make sure everything in the fuel system/carbs is tight and not allowing air in. That will cause major headaches until resolved.
 
nwcove

nwcove

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Re: I am STUMPED! please HELP!

chiefcatchemall said:
Well I have some very bad news guys...I went to put my new head gasket on and I looked at my piston heads and they are BLACK again. This is only after running it for about 5 mins in a can...Does this mean my rings are shot? I shouldnt have taken his word for the compression...Not very happy about it. I have replaced the magneto, rebuilt the fuel pump and carb, and did a lot of other work to it. There is no turning back now...Any ideas what it will set me back?..and where I can get these parts?...the cyl walls look in good shape..

so you didnt do the compression test yourself? you should do it and post the numbers. black piston crowns and plugs arent the end of the world, more like its running rich.


This doesnt make me happy, but its good in a way. I have really started to learn this outboard, and I am assuming after new pistons, and rings and everything it should be like a newer motor. Lesson learned here is to not take anybody's word!!!
Click to expand...

so you didnt do the compression test yourself? you should do it and post the numbers. black piston crowns and plugs arent the end of the world, more like its running rich.
 
nwcove

nwcove

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Re: I am STUMPED! please HELP!

........not sure how i added my thoughts to the op's post in the quote?????? yikes!!!!!
 
RogersJetboat454

RogersJetboat454

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Re: I am STUMPED! please HELP!

If the compression numbers are correct, and it does sound like its trying to run, I wouldn't go ordering a set of pistons and rings quite yet, as it sounds like they are probably fine.

As it's been pointed out, you have to hold the throttle open at WOT to get this to run, and everything gets coated in black, this says VERY rich fuel mixture to me.
The choke is to the open/run position while you are trying to run this correct? Also, when you go to prime the fuel system, does the fuel bulb on the fuel line eventually get firm, or does it stay soft? If it stays soft then fuel is most likely entering your crank case either through the carb or fuel pump when it shouldn't be.
 
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chiefcatchemall

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Re: I am STUMPED! please HELP!

it seems to stay pretty hard...I prime it before I start the motor..
 
Brokeback Johnson

Brokeback Johnson

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Re: I am STUMPED! please HELP!

Your compression is fine. Get the carb and fuel pump straightened out and it should run well IMO.
 
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tx1961whaler

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Re: I am STUMPED! please HELP!

Is the nozzle gasket (#40) in there?
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chiefcatchemall

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Re: I am STUMPED! please HELP!

yup, it sure is. But I did notice when I went to screw my slow speed needle in (#42) it wouldnt screw in with part #35 sitting in there. I believe its the needle bearing? I did also notice that when rebuilding the carb there wasnt one in there before either...
 
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Haffiman

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Re: I am STUMPED! please HELP!

LOL, that was a good one!! #35 is the seat for the needle valve. Without it is like having no jet in the carb, fuel flows freely. No wonder you are running black and sooted plugs.
 
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chiefcatchemall

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Re: I am STUMPED! please HELP!

haha, I didnt see one in before hand! the needle valve still screwed in tight. I couldnt get the needle valve to screw in with the seat in
 
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chiefcatchemall

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Re: I am STUMPED! please HELP!

why would my top piston head only be black? The lower one wasnt nearly as bad...
 
RogersJetboat454

RogersJetboat454

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Re: I am STUMPED! please HELP!

chiefcatchemall said:
haha, I didnt see one in before hand! the needle valve still screwed in tight. I couldnt get the needle valve to screw in with the seat in
Click to expand...

You need to investigate this. Despite the fact that you say the needle is screwing in tight (and please do not screw these needles in too tight, they are easily damaged by anything more then a light seating), that may not mean that the needle is coming in contact with a proper seat. This needle metering the proper size orifice is everything as far as fuel mixture is concerned. #35 is not an omissible part. Pull your needle out, and get a bright flash light to carefully examine the inside of the opening. There is a good chance someone may have seriously buggered this up, especially if they tightened the needle down too tight.
 
oldcatamount

oldcatamount

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Apr 4, 2010
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Re: I am STUMPED! please HELP!

Did you re-check the compression numbers? Also, what plugs do you have in it? They should be Champion J4C gapped at .030.
 
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chiefcatchemall

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Messages
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Re: I am STUMPED! please HELP!

RogersJetboat454 said:
You need to investigate this. Despite the fact that you say the needle is screwing in tight (and please do not screw these needles in too tight, they are easily damaged by anything more then a light seating), that may not mean that the needle is coming in contact with a proper seat. This needle metering the proper size orifice is everything as far as fuel mixture is concerned. #35 is not an omissible part. Pull your needle out, and get a bright flash light to carefully examine the inside of the opening. There is a good chance someone may have seriously buggered this up, especially if they tightened the needle down too tight.
Click to expand...


Okay I will be taking a look here in a minute. Thank you
 
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