OMC 2.3 L - Backfiring @ start up and then hard to start

[natecollins]

Hi,

I am working on a 1989 OMC 2.3 L. The owner of the boat has not used the boat for about 3 yrs. I did the following:

Sucked out old gas and replaced w/ new.
Replaced spark plugs
replaced oil & filter
replaced water separating fuel filter
replaced lower unit oil
replaced water pump impeller

Upon trying to start the engine up, it was backfiring and would not start up. I found that the shaft that turns the distributor and fuel pump had a stripped out gear. I replaced the shaft. everything seems to turn freely, so I am not sure why this would have stripped out.

Now when I try to start the engine for the first time, I have to move the throttle back and forth a few times and then put the throttle in a far advanced position. The engine backfires a several time upon starting up, but then runs smooth in idle and at higher RPMs. I do notice a couple of pops (backfire at the flame arrester for the first minute of running). The timing shows steady at 10 btdc. After running for a few minutes I turn off the ignition and try to restart. It is always hard to restart and backfires at first, but once I get it running it stays smooth again. I pulled the line after the fuel pump to see if it was pumping, and it appears to be pumping fine. The electric choke on this motor is broken and is no longer available through OMC. I would imagine this would have some to do with it being hard to start the first time, but I wouldn't think it would cause it to backfire each time you try to start it up. Please help.

Thanks,
Nate

 

[Haut Medoc]

Re: OMC 2.3 L - Backfiring @ start up and then hard to start

Possibly lean fuel from crap in the carb.....
Check timing......
Check condition of ignition wires.....​

 

[1730V]

Re: OMC 2.3 L - Backfiring @ start up and then hard to start

Check your cam to crankshaft timing. That engine has a timing belt. It will run with it jumped one tooth, but it will backfire.

That is a Ford Industrial Engine. It is serviced by Ford Power Products Distributors. (Google search Ford Power Products) It differs, little, from an industrial engine other than the marine stuff: manifolds, carburetor/fuel pump/alternator and starter.

Ford Power Products (not car/truck dealers) should be able to fix you up with the choke parts. By the way, it is 128 HP at the propshaft.

 

[natecollins]

Re: OMC 2.3 L - Backfiring @ start up and then hard to start

I checked the belt timing and it was off about 6-8 degrees. I think the timing belt may be stretched because I can either get it about 6-8 btdc or 10 atdc when the cam mark is where it is supposed to be. It is very hard to get the belt notches to fit in the grooves of all gears at the same time before tightening up the tension wheel. I am going to buy a new timing belt then try it again.

 

[a70eliminator]

Re: OMC 2.3 L - Backfiring @ start up and then hard to start

Double check the fireing order, the popping & backfiring is the clue, I think all of us have been bit by that one.

 

[natecollins]

Re: OMC 2.3 L - Backfiring @ start up and then hard to start

Thanks,

I put the new timing belt on and the same situation occured. I can never get the cam and the crank shaft to match up perfectly. I am either about 10 degrees before or after tdc based on how I install the belt. I had installed and checked the spark plug wires a bunch of times during the repair process, but decided to recheck them after the last comment to this post. Sure enough, the were installed in the wrong order. I appreciate you helping me catch my mistake. Everything seems to be running good now and I am going to test it on the lake in a few minutes. I am still a little concerned that the crank and cam can not line up perfectly.