Engine rotation

[paul1970]

I've recently purchased a searay sundancer 300, the left engine starts no problem , but the right engine needed a new starter so I ordered one , but it wont start it just back fires through carburettor, are these engines same rotation ? 1992 5.7 260 hp v8 mercruisers, also left leg says counter rotation on it , any help or info is appreciated

 

[hottoddie]

One way for you to determine if the engine is reverse rotation is to check the location of the plug wires on top of the distributor. Compare to the port engine. My guess is by 1992 both engines are standard rotation and one has a reverse rotation outdrive.

 

[paul1970]

Ok thanks , any ideas as to why it won't start , just back fires out the carb , im thinking timing issue

 

[hottoddie]

Ok thanks , any ideas as to why it won't start , just back fires out the carb , im thinking timing issue

Of course timing could be an issue but start by checking the condition of the distributor cap and rotor. If moisture is present it will cause ignition cross over and cause those symptoms.

 

[Flyer5]

You may be able to tell by the timing tab marker on the front of the engine as well. If both engines timing tabs are the same they probably turn the same as someone previously mentioned.

 

[ttmott]

Where is the starting motor mounted? On the underside of the engine like on an automobile or on the back of the flywheel housing? 1992 era all engines Mercury used were standard rotation from what I know. Earlier, some of the Chrysler engines were counter-rotating and I've heard of some BBC's counter-rotating. The first thing is to mark where the No. 1 spark plug wire is on the distributor body then pull the cap off and note the location of the rotor with respect to where that mark is. Then rotate the engine around until the 8 Degree BTDC mark is aligned with the indicator on the crankshaft dampener. If that distributor rotor isn't either directly on the mark you made or exactly 180 degrees opposite then the timing chain has failed or the distributor has rotated out of position. Most GM based engines used plastic coated cam timing gears and over time the plastic breaks off and the timing goes kaput.