454 crusader back fires in rpms of 3200?????

[elbichommp]

can any one help?motor back firesd in rpms of 3200..starts fine idles fine and runs fine up until about 3200 rpm.also haveing a bit of heat issue...related in any way???

 

[bassboattech]

Re: 454 crusader back fires in rpms of 3200?????

first thing id do is a compression test and then a leakdown test. this will tell you if the motor is mechanically sound

 

[Alpheus]

Re: 454 crusader back fires in rpms of 3200?????

first thing id do is a compression test and then a leakdown test. this will tell you if the motor is mechanically sound

That will tell you if you have good compression and does not mean its mechanically sound.

Where is the boat backfiring from? Exhaust or out of the carb?

Could be a timing issue (ignition After TDC or way before TDC, valve not seating,plugs,wires distributor. Overheat could be a cooling issue or your engine is running to lean. Need more info to determine...

 

[JustJason]

Re: 454 crusader back fires in rpms of 3200?????

A compression test never hurts (although time consuming on a 454) You can shortcut that to a degree if you have a KV meter.

When was the last time the engine had a complete tune up???

Try running this test as well;
http://forums.iboats.com/showthread.php?t=283269

Part of diagnostics is spending time figuring out what is NOT wrong

 

[Bondo]

Re: 454 crusader back fires in rpms of 3200?????

motor back firesd in rpms of 3200..starts fine idles fine and runs fine up until about 3200 rpm.also haveing a bit of heat issue...related in any way???

Ayuh,.... Check,+ Change the fuel filters....If it's going Lean, it could be the root cause of the Problems...

 

[TilliamWe]

Re: 454 crusader back fires in rpms of 3200?????

Is the bottom of the boat dirty?