Wont start

[Days away]

Just bought a murcruiser 302 with a 888 outdrive.
It will start it backfire and pops through the carb.I have not done a compression check yet .
I have checked the firing order and so forth though.ANY OTHER IDEAS.?????

[Fanie]

Make sure the ignition timing is right. If this is out the firing is done out of sink with the cylinders and the motor won't run.

If the firing timing is correct then there can only be only two things, fuel and spark. If there is fuel and spark it must go.

[Days away]

I was doing the wrong firing order come to find out it is a 5.0L HO.Thanks anyway.Sherman

[PAR]

Clearly there is fuel and spark Fanie, otherwise it wouldn't be back firing!

It sounds like it could be one a several things, but more detailed information is necessary and a procedural diagnosis begun. It's likely a fuel delivery issue such as a stuck needle or float, from gum or varnish.

How long since it's been running normally? Is this a sudden departure from normal or have things been slowly getting worse until now? How old is the fuel? The fuel filters? Water separators? Any leaks?

In all honesty, a mechanic can take a quick look and figure out what issue(s) you engine has in a just a few minutes. A few simple tests or checks and he'll be ready to order parts. It would be a wise investment to get a repair manual for you engine/drive combination (at the very least) if you expect to do any real service on your boat.

[CDK]

The most logical explanation for an engine to backfire is that the mixture is too lean. One or more jets clogged, sediment in the carb etc., quite normal for engines that have been out of service a long time.

[gonzo]

The 302 and the 5.0 are the same engine. Make sure you are timing it like a Ford and not a GM. I have seen that a lot and it will backfire like you say. 1-4 cylinders on left bank.

[Frosty]

Gonzo means the rotation of the distributor is different, Ford-- GM.

East to see way of rotation ,--its the way the rotor arm advances.