OMC Backfiring

[DirtBikeFanatic]

Ok I have a 1988 OMC 3.0 litre GM, I have rebuilt the Carb. put in a water fuel separator, changed the fuel filters and changed the dist.cap, points, plugs and plug wires (they didn't have a new rotor button) and I am still getting backfiring thru the carb and no acceleration...Could it be a timing problem??? I am at wits end with this thing, this is a problem I have been trying to deal with for the past few weeks....btw it runs great when there is not a load on it but as soon as I hit the water and put it in gear the backfiring starts..
Any help is greatly appreciated...Thank You

 

[Bt Doctur]

Re: OMC Backfiring

compression and leakdown to rule out a burnt valve

 

[DirtBikeFanatic]

Re: OMC Backfiring

I'm an idiot I don't know what you mean by what you said, please clarify thank you

 

[a70eliminator]

Re: OMC Backfiring

Double check you firing order.

 

[DirtBikeFanatic]

Re: OMC Backfiring

Thank you I will go have a look see at it and will give you an update....Thanks again