Johnson 1984 115 excessive smoke problems

[reb0707]

I recently purchased this engine and it seems to smoke a lot. The motor will usually fire imediately and stay running. Yesterday I noticed for the first time oil drip from the prop. I guess thats unburnd fule oil. I am running 50:1. No VRO. My mechanic said the thermostat had been removed and I didn't need one here in Florida because the water stays warm. I fellow boater told me yesterday to put one back in because the engine is not getting hot enough to properly burn the fuel. If my fellow boater is right where does this thermostat go? About how much do they cost. I am sure I can install on if I need to. Thanks All

 

[Daviet]

Re: Johnson 1984 115 excessive smoke problems

Take a look here, #124, maybe it will help.
http://www.ishopmarine.com/ishop/js...nown&isFrPG=false&forItemCode=&pCode=C0081525

 

[Daviet]

Re: Johnson 1984 115 excessive smoke problems

Forgot to mention, yes you should run thermostats to keep engine at proper temp.

 

[Monte1961]

Re: Johnson 1984 115 excessive smoke problems

Most engines are designed to run there most efficient at certain temperatures. Manufactures dont just put t-stats in because they can. Heat makes horsepower. So running a cold engine simply isn't the norm anymore.

 

[Auxlarry]

Re: Johnson 1984 115 excessive smoke problems

I live in central FL and was told the same by a mechanic. Ran my engine for a few months without the t-stats and noticed a increase in fuel usage, a bigger fuel/oil slick in the water when I docked and a noticable difference in engine performance. Reinstalled the stats and the engine runs like it should!
Agree with Monte...the engines are designed to run a certain temp and t-stats are the answer!

 

[reb0707]

Re: Johnson 1984 115 excessive smoke problems

Thanks guys, the thought of better gas milage was enough to get me to order #124. Are there any other gasgets I may need as well? Also davit, any thoughts on this post about my motor running too high? http://forums.iboats.com/showthread.php?t=482467&p=3262978#post3262978?

 

[countvlad]

Re: Johnson 1984 115 excessive smoke problems

tstat could be one of you problem but also a good decarb and checking the fuel recirculation check valves might not be a bad idea, with time they get stuck and dont circulate unburned fuel/oil. without the vro your motor burns 50:1 oil at idle unlike 100 or 150:1 with the VRO. that makes a big difference. you could try different oil and see how it does...

also, i've seen a big difference in smoke after i changed the reed valves to boysen reeds...