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Timing on a 350 mag mpi

quadraboats

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"The engine is a 2004 350 MAG

"The engine is a 2004 350 MAG MPI.

I dropped the engine into my ebbtide on the weekend, took it out today and it was running brilliantly, for about 40 minutes.

All of a sudden it starting pinking and back firing so i turned the boat off and called for a tow back into the local marina. Whilst in the marina i tried to start the boat up again and it wont !

The engine has just been put back together again with all new gaskets and re-conditioned heads. The only thing I can think that may be causing this is the timing, although I was under the impression it was controlled by the ECM ?

HELP.

Thanks in advance."
 
"So why did a 5 year old motor

"So why did a 5 year old motor need the heads removed?
The ecm controls and monitors almost everything.
you need to do some basics as ,spark,compression, fuel delivery, etc."
 
The valves in cylinder 6 had t

The valves in cylinder 6 had tuliped.

I am going to test the compression and the fuel pressure etc in the morning. I am just praying that something serious hasn't gone wrong again.
 
"did you determine the cause,

"did you determine the cause, water ingestion or a very lean fuel mix?
may have damaged the valve again"
 
"The cause was water in the fu

"The cause was water in the fuel.

Guy:

This could be the problem, a previous mechanic damaged the dizzy cap and at the moment its only being held on by a zip tie. The leads are all brand new, but will check to make sure one hasnt come loose.

BT:

I am praying another valve hasn't gone. A compression test in the morning will tell me more regarding the internals."
 
"water in the fuel is a condit

"water in the fuel is a condition, the question is,was that injector damaged by the water?
the cap is bolted down, explain the zip tie, cause a loose cap can break a rotor."
 
"The flow rate on the injector

"The flow rate on the injectors were down, all of them were sent to be cleaned and renewed. The injectors on the engine now have a proven flow rate and are performing at 100%. At the time the fuel pump and filter were both replaced. The fuel tank was dried and filled to the brim with higher octane fuel, the fuel pressure was good when the engine was fired up for the first time.

Regarding the dizzy. The unit it self is bolted down by the U peice and a single bolt but the actual cap covering the rotor arm, is the part which was broken.

Usually there are 2 small hex bolts holding the cap on, but the thread on one side has been snapped off from over tightening therefore I have a zip tie round the upper half of the unit. A gentle wiggle and the cap felt fairly secure."
 
The lug on the bottom half whe

The lug on the bottom half where it screws into is the part that is broke.

You think the cap could cause a problem ?
 
A loose cap could do it. Is t

A loose cap could do it. Is there enough room on the dist. base that the cap rides on to drill and tap a hole for a smaller screw?

Put a timing light on it while it's cranking or running to see if there are consistent pulses.
 
"Went down to the boat this af

"Went down to the boat this afternoon for a look and I think ive found the problem. The two screws that hold the rotor arm unit down had come loose and the rotor arm unit itself was dislodged.

Although after re seating, the boat still wouldn't fire so I think its time for a new unit."
 
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