Engine Wont Turn Over

[DemersChrisG]

Hello there ladies and Gents. I have a carburated chevy 350 inboard that wont turn over. I just got done tearing apart the engine to replace seals within the motor. I put it all back together and not it wont start. The fuel pump is working and its getting gas because its backfiring back up through the carb. Anyone have any ideas?

 

[crazy charlie]

Re: Engine Wont Turn Over

Could be crossed sparkplug wires or the distributor is not in correctly.Charlie

 

[DemersChrisG]

Re: Engine Wont Turn Over

If the distributor is in correctly it should sit in flush, and the contact point should be spinning correct?

 

[crazy charlie]

Re: Engine Wont Turn Over

Sorry,I only watched my mechanic put mine back in years ago.If I recall correctly the #1 cylinder had to be at the top to do it correctly but that was a long time ago so I am sure I am heading you in the right direction but do some research before you take my word for it.Charlie

 

[Don S]

Re: Engine Wont Turn Over

Yes, it should set flush, but it also has to be in the correct position with the rotor pointing to #1 TDC when the engine is at #1 TDC on the compression stroke.<br />This is from the Merc service manual.<br /><br />

 

[jeff13601]

Re: Engine Wont Turn Over

The plug wires on wrong are not going to stop the motor turning over. Do you mean it wont turn over or it is turning over but wont start?

 

[DemersChrisG]

Re: Engine Wont Turn Over

I checked my wires and plugs. They are all getting sparks. I am getting fuel. I was able to get the Engine to turn over by manually closing the electric choke. But then it ran rough and shut down after about 15 seconds or so. <br /><br />One thing I didnt do is position the rotor to the #1 cylander at Top dead Center. Do that really mess with the engine that bad? I didnt realize that was that important.

 

[jeff13601]

Re: Engine Wont Turn Over

You have to do what Don told you. If they are not in the right order the engine will not run. It could run rough if two of them were switched

 

[DemersChrisG]

Re: Engine Wont Turn Over

Ok, here is the update. <br /><br />1. The wires are all in the correct firing order. Chev350 1 8 4 3 6 5 7 2<br /><br />2. Spark plugs are receiving their sparks.<br /><br />3. Carb is getting fuel<br /><br />4. The rocker arms were loose, but I tightened them all so that the slack in the pushrods were gone. (I rotated the crank multiple times then re tightened them on both sides of the engine)<br /><br />5. The battery is cranking the engine weak, so I suspect that could be a factor. But is there anything else that anyone can suggest? I want to get this thing in the water tommarow morning......<br /><br />Your input is greatly appreciated. Thanks guys.

 

[jeff13601]

Re: Engine Wont Turn Over

How old is the gas? How long has the boat sat? Do you have points or electronic? You had the dist out, did you reset the timing or mark where it would be close before you removed? Are you sure you got the number one cylinder right? What shape is the carb in? We need this info along with the year.

 

[Don S]

Re: Engine Wont Turn Over

The rocker arms were loose, but I tightened them all so that the slack in the pushrods were gone. (I rotated the crank multiple times then re tightened them on both sides of the engine)<br />

Have you ever adjusted valves on a Chevy engine before? Do you have any kind of a service manual you are using, or is this all done by the seat of the pants method.<br />There is a procedure for adjusting valves without the engine running.<br />Try this.<br /><br />

 

[DemersChrisG]

Re: Engine Wont Turn Over

Hey Don, I was just wondering as to where you came across these diagrams. It there somewhere online you went to get these?

 

[Don S]

Re: Engine Wont Turn Over

All the information i've posted is out of a Mercruiser service manual. But you need to find a manual for your particular engine model and year. So far I don't have a clue what you have except it's a Chevy 350 of some undetermined year.

 

[DemersChrisG]

Re: Engine Wont Turn Over

Its a 1980 Chev. 350. Does Mercruiser have a website with publications for their engines?

 

[Don S]

Re: Engine Wont Turn Over

You can get them from Merc if you know the serial number of your engine.<br /> Merc Service manuals<br /><br />or you can go here and and order by engine and year.<br /> Merc Manuals 2