fring order on mercruiser 140

[mr.mechanic]

I bought seaswirl a few years back never had chance to get arround to it now i do. First there was no spark fixed that problem now i cant seem to get the firing order right. So i looked on here and it said it was 1342 and i tried that and now it wont even start. Before it would start up but wouldnt stay running unless i ran it off of 3 cyclenders. Im not even sure what the firing order was befoire i changed it can anyone help me im not sure what year it is because i cant seem to find a hull number or serial number on the boat and when i bought the guy never gave me any paperwork on it. I dont know what do with this thing im ready to junk it.

 

[Don S]

Re: fring order on mercruiser 140

First you have to determine where #1 TDC on the compression stroke is. Once you have the crankshaft set to that, look at your distributor rotor and determine where it is pointing. That is #1TDC and where #1 spark plug wire should be. Doesn't matter what the book says it should be, if some one put it in at a quarter, half, or three quarter turn off, it will still run and time out fine. Just not where the book says it should be.
That is just a fact of how engines actually work.

 

[mr.mechanic]

Re: fring order on mercruiser 140

Thanks for replying. Where should spark plug on be in the front or the back of the engine? Ive never worked on a boat before

 

[Bondo]

Re: fring order on mercruiser 140

Ayuh,......

#1 is the Forward cylinder,...... #4 is the Aft cylinder......

 

[Don S]

Re: fring order on mercruiser 140

You aren't working on a boat, you are working on an engine. On any inline engine #1 cylinder is on the front of the engine.
What engine EXACTLY are you working on? While the firing order won't change, the possibility of a free online service manual (that you really need) may be online.

 

[mr.mechanic]

Re: fring order on mercruiser 140

the engine is mercruiser 140 and thats all i know. Ive heard that its the same as a 140 chevy engine

 

[mr.mechanic]

Re: fring order on mercruiser 140

i will find out exactly what it is tommorow because its dark right now

 

[brunolund]

Re: fring order on mercruiser 140

it is 1-3-4-2. it has been for 40 years.
agreed with doing it by which way the distributor is pointing, but make sure your on TDC between compression and power.(timing pointer at 0 degrees, BOTH valves closed. the engine is identical to one in a car