... Worth a thousand words and posts

[jafa]

Hi All<br />I've been following the "sticky rings" thread in the Johny and Erude forum quite keenly. Before the pictures were posted comments like "if the damage is not too bad " and " a small amount of scuffing" were going round. After the pictures that changed to " That's toast" and " beyond repair" under more critical examination. <br />For those of us who only work on our own outboards a graphic example of something gone horribly wrong leads to the next question , " What does it look like just before it goes horribly wrong."<br />In the frequently asked questions forum could those who see the insides of motors on a regular basis take some photo's of what things actually should look like and post them up. <br />I've got the clymer manual for my twin stroke Suzuki DT40 but the photographs relating to piston colouration are not much help , the drawings for spark plug condition are awful and i'm sure only relate to four strokes.<br />What I'd like to see would be something like Plug contamination caused by ... , initial signs of overheating , pee streams before and after the impeller change.<br /><br />Comments or any ideas .?

 

[llfish]

Re: ... Worth a thousand words and posts

Great idea

 

[Dhadley]

Re: ... Worth a thousand words and posts

Those pictures are very very typical of coking damage. It would be unusual for that motor to be "beyond repair". Sure you cannot use the piston again but the cylinder is going to need to be bored anyway. Even if it wasnt scuffed its going to be out of round beyond the wear tolerance.<br /><br />That picture is exactly why we do everything possible to keep combustion temps down.

 

[jafa]

Re: ... Worth a thousand words and posts

Keeping combustion temps down runs completely counter-intuitvly (?) , you would expect compustion temps to be high to burn off the lubricating oil , thats another thing i've just learned <br />Could somebody please post some pics of what a two or three cylinder piston or cylinder head 2 stroke should look like.

 

[Dhadley]

Re: ... Worth a thousand words and posts

www.eric-gorr.com/techarticles/pistondiaguide_ta.html

 

[Dhadley]

Re: ... Worth a thousand words and posts

My mistake. When I said we try to keep them down I meant down as opposed to too high. Running the wrong heat range plugs, wrong fuel, lugging, wrong timing -- things like that will add combustion temp. There is a point that things will go terribly wrong.

 

[jafa]

Re: ... Worth a thousand words and posts

I think where I'm heading is something like " 10 things that could save your powerhead". Were all familiar with the regular maintenence items , plugs, impellers, t-stats etc but once in while you see a little gem of a test that most home mechanics can perform. I'm thinking here of something like pump the bulb up and see if holds pressure for 30 minutes , if not fuel is leaking out somewhere. Its the sort of test you could do once or twice a season before a small problem becomes a bigger problem. I would imagine that most of the posters on this board are ocasional users of their boats and , like watching your kids grow up , something seems to happen overnight when in fact it was a much more progressive problem that wasn't picked up early.