Engine Decarbonizing

[JimS123]

After reading all these oil threads, I got to wondering whether I have been lax in maintenance all these years. Never decarbonized one yet.

The motor I'm concerned about is a 1984 Evinrude 9.9 sitting on an OMC bracket on a 19' bowrider. It has a sailboat prop to keep the rpms higher. I did have some issues with plug fouling the first year, but got that resolved.

The motor is used strictly for trolling at 1.9 mph. It is usually run once or twice a week in season for 4 hours each time. At the end I run her up to full throttle for a few minutes. Originally, it smoked when I did that, but as I said those issues were resolved.

Anyway, last fall the motor turned over 600 hours. My question is should I decarbonmize or leave well enogh alone?

 

[foodfisher]

Re: Engine Decarbonizing

Two thoughts. Decarb can't hurt and "if it works, don't fix it"

 

[CaptainHook]

Re: Engine Decarbonizing

Two thoughts. Decarb can't hurt and "if it works, don't fix it"

What kind of advice is that??? Do it, don't do it???

 

[Silvertip]

Re: Engine Decarbonizing

Decarb will not hurt the engine. If it has never been done, do it. If you see no difference, only a few bucks were lost in an attempt to prolong engine life. However, if the engine has been used primarily for slow speed trolling it will benefit from the decarb process. You might want to check compression before and after.

 

[kenmyfam]

Re: Engine Decarbonizing

Yep, give it a decarb.

 

[JimS123]

Re: Engine Decarbonizing

. You might want to check compression before and after.

Should the compression go up or down?

 

[foodfisher]

Re: Engine Decarbonizing

If it needed it the compression will go up. Captainhookbviously the answer is yes.

 

[AguaSki]

Re: Engine Decarbonizing

You should see compression increase because your piston rings are sealing better once the carbon has been removed.

 

[Proselect]

Re: Engine Decarbonizing

I just bought a new to me fishing boat last year with a rude 112. I would like to decarbonize it for the fact I am not sure if its ever been done. Can somebody explain how or point me to a good thread. I will do some more searching. I do have the schrader valve on mine.

 

[ondarvr]

Re: Engine Decarbonizing

I just bought a new to me fishing boat last year with a rude 112. I would like to decarbonize it for the fact I am not sure if its ever been done. Can somebody explain how or point me to a good thread. I will do some more searching. I do have the schrader valve on mine.

http://forums.iboats.com/forumdisplay.php?f=31