Smoking exhaust and spark plug questions 1977 135HG Chrysler

[seattle scott]

Exessive smoke/steam is the issue. I don't think steam/blown gasket, since compression is 118-120 psi all cylinders. Any thoughts on this? Seems like excessive/unburt fuel. Spark plugs all look the same, no brownish residue - just too clean with fuel on them. Pics are of same plug, just wiped my finger across it to make plug "clean".

I am enjoying the family this Christmas and waitng for the dishes to stack up before I have to get back to work in the kitchen.

 

[maverick974]

Re: Smoking exhaust and spark plug questions 1977 135HG Chrysler

I'm not a mechanic but I am familiar with plugs that look that clean. I'm guessing you're getting water in the combustion chamber somehow. Head Gasket maybe?
In my experience, I had a head gasket go bad allowing water in the combustion chamber. The water made the spark plugs look brand new. Since 2 stroke engines have oil in the fuel, the plugs get a tan, brown or slightly black coating on them from the burning oil.
My guess would be a head gasket even though the compression is even on all the cylinders but I'm sure one of the tech guys on here will show up soon to give you their opinion.

 

[Frank Acampora]

Re: Smoking exhaust and spark plug questions 1977 135HG Chrysler

How old are the plugs? If you just installed them, don't expect too much accumulation on them. How fast was the engine running? at anything over an idle, on muffs or in a barrel, you would expect that much smoke.

And best you take that engine and remove the black paint before I come out there and give you what for. LOL. Seriously though, I believe they look better in white or the original cream and the black will get so hot that it will age quickly in addition to burning you if you touch it.

 

[jerryjerry05]

Re: Smoking exhaust and spark plug questions 1977 135HG Chrysler

New plugs!!
Setting in a tub and ideling it's gonna smoke a bunch.The longer you idle the more it's gonna smoke.
These motors are meant to run faster than an idle.
The gas and oil isin't regulated like most newer outboards.
My twin 88/85 smoke like crazy on start up.But once I get moving they stop.

 

[tater76]

Re: Smoking exhaust and spark plug questions 1977 135HG Chrysler

Its got to be cold if your in Seattle (just guessing from your handle) you will get steam from warm exhaust water, and alot of smoke as Jerry and Frank said are normal.

 

[seattle scott]

Re: Smoking exhaust and spark plug questions 1977 135HG Chrysler

Thanks all. Plugs are new - they have maybe a total of 30 minutes run time on them. Engine starts right up and runs pretty smooth, but does the smoking thing without change from cold start through warm up ten minutes later. Plenty of coollant water coming out ( new impeller) and temp here in Seattle is about 45F. With inline tester I am getting good spark at the plugs, fresh gas and 50:1 mix. I fixed the dripping carbs with new inlet needles and adjusted the floats. So based on all the comments, I will leave this smoke issue alone for now and move on to the "no charging" issue and the tilt/trim rebuild.

From what everyone else has said on the forum, I assume I am good with the 118-120 compression, even though new spec is 150-165. I have Sea Foamed the engine.

Frank, will paint to white - unless I get the "Black Ops" contract from Fish and Game.

You guys are a great bunch - great bunch of what- I haven't figured out.

 

[jerryjerry05]

Re: Smoking exhaust and spark plug questions 1977 135HG Chrysler

The compressin is low but that can be your guage.All plugs out?
My guage might read a lot more than yours.There is a difference in guages.The less expensive
(cheaper) don't read as well.Mine cost over #100 in 1986.
Trying to say as long as the results are close.That's what counts.120 is good.
Will take some time in open water for the extra oil to go away.J