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83 Mercruiser 470170Hp back firing through carb

haymannnh

Member
"I believe I got the firing or

"I believe I got the firing order correct now,I brought piston 1 up to TDC and rewired from the cap 1,3,4,2 firing order.
Now when I crank this pig it back fores through the carb and we get a little camp fire going in the carb throat.
Timing off?Distributor to far advanced?"
 
"Are you sure you wired the ca

"Are you sure you wired the cap in the correct direction (CW vs CCW)?
To be sure, pull the cap, crank the engine and note which way the rotor turns.
Also check your initial timing.
Just a thought.
Rod"
 
"I checked the rotation of the

"I checked the rotation of the rotor which is cw,set cylinder #1 at TDC and turned my distributor so that wire# 1 is lined up with the rotor.Then made sure that #3,4,and 2 were in the correct spots on the cap and still get the same thing.
The grove on my balancer on the front of the motor is also line up with 0 on the timing marks when pist #1 is at TDC.
I am at a loss,have been messing with these for years on cars and never had a problem like this."
 
"hey donald..
try flipping


"hey donald..
try flipping the dist. 180 degrees, you might have set the tdc on the wrong cycle, i.e., on the intake cycle instead of exhaust, worth a shot"
 
that was happening to me on my

that was happening to me on my boat and what i found was the problem was the rotor in side the cap was to big or some thing and was stuck on the number 2 cyc and was stripped out so it would not turn
 
"Well I got it to fire up toda

"Well I got it to fire up today,found out that I was 180 Degrees off on the distributor,once I resolved the problem it started like a charm and I was able to set the timing and dwell.
Thanks for all the input,now I just need to straighten out some small electrical issues from the previous butcher, change the oil and I am going to change the gear oil in the lower unit and test drive her next weekend."
 
"I used a fram ph 5 oil filter

"I used a fram ph 5 oil filter which was the replacement for the dh540 that was on there.Took it out yesterday for her madien voyaage and it works great.Still need to run the old gas out of it but but it still ran very good.
The only issue I had was when I wen to load it on the trailer and it stalled and cranked really heard to get started again.
Brought it home and my suspision where right,the bolt for the distributor was not tight enough and the distributor turned and timing was off again.
reset the timing to 8degrees advanced and tightend bolt and is running good again.My top speed was approximalty35 mph."
 
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