determining 2 or 4 stroke

wisconsin guppy

Recruit
Joined
Aug 1, 2003
Messages
1
How can one tell if an outboard is 2 or 4 stroke just by looking at it? Do all 2 stroke engines need mixed fuel? How do the crank and rod bearings get lubricated if there is no oil reservoir? My model J8RCRW is an '84 Johnson 8hp, s/n E5879955. My dad bought it new, ran it for about 10 hours (tops), then stored it in the garage for the next 10 years. A month ago I put new gas (in a new tank) and motored about for 10 minutes but it died. The mechanic then put a carb kit on it but said it may need new crank and/or rod bearings soon. Did I hurt it by not mixing my fuel?
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
Messages
10,161
Re: determining 2 or 4 stroke

Hi guppy,<br /><br />All two strokes need some way of getting oil to the bearings or other metal to metal moving parts whether by mixing the lubricant directly with the gas, having it mix in a special pump or by having a pump that does nothing but pump oil to the moving parts.<br /><br />In your case, you need to mix the fuel/oil together in order to get the lube to the bearings or other moving parts.<br /><br />The mix ratio for your engine is 50:1 or 16oz of two stroke lube to 6gals. of gas. The lubricant used should be made for marine engines. Most say TCW-3 maringe lube.<br /><br />Did you hurt your engine? Hard to say. I've heard of larger engines running through a half tank of gas without lube and surviving.<br /><br />To be on the safe side, have a compression test done before restart. Did the mech who did your carb run the engine? If he did, then mix some lube with the gas and run. The additives in the gas may have been enough to save the metal to metal parts in your engine. Monitor the engine temp closly. Look at the spark plugs for any sign of metal deposits. It's a 50/50 deal guppy but I think the odds are in your favor. Keep us posted and thanks for posting on the iboats forums.
 

bossee

Senior Chief Petty Officer
Joined
Jul 18, 2002
Messages
727
Re: determining 2 or 4 stroke

How can one tell if an outboard is 2 or 4 stroke just by looking at it? <br />---------<br />Hi,<br />Many 4-strokes has a label on the outside of the cowl "4-stroke" or "four-stroke".<br /><br />Do all 2 stroke engines need mixed fuel? <br />---------<br />Yes, premixed directly (by You) in the fueltank or mixed automatically from a oil reservoir and oil pump (usually inside the cowl).<br /><br />How do the crank and rod bearings get lubricated if there is no oil reservoir? <br />-------<br />They get not lubricated then... not good at all as You can imagine so that is why in your case You must pour 2-stroke oil in the gas tank.<br /><br />My model J8RCRW is an '84 Johnson 8hp, s/n E5879955. My dad bought it new, ran it for about 10 hours (tops), then stored it in the garage for the next 10 years. A month ago I put new gas (in a new tank) and motored about for 10 minutes but it died. The mechanic then put a carb kit on it but said it may need new crank and/or rod bearings soon. Did I hurt it by not mixing my fuel?<br />-------<br />Maybe, maybe not. Pour 2-stroke outboard oil in<br />the gas tank with mixture:<br /><br />50:1 (gas:eek:il)<br /><br />Good luck.
 
Top