Mercruiser not running---still

[jedimaster]

Ok, so After changing the head gasket I have compresion between 105 and 110 on all 4 cylinders
Timing is dead on at 6degrees btdc while cranking with muffs on
New spark plugs
New cap
New rotor
Plugs are gapped right
Has strong white/blue spark

Still not running.
I have tried draining the carb and fuel lines and running direct off of a can of fresh gas and still no dice.

Not even a rumble studder and quit
Just cranks over and won't fire

I am going to eb picking up a carb rebuild kit this afternoon and trying that tonight as it is due for a rebuild anyway.

I have tried pouring straight gas down the carb and still nothing.

The only thing is I noticed the plugs seem very wet and may be flooding(hence the carb rebuild kit).

Anything else I should be looking at?

It ran fine last year when it went into storage.

Its an 88 3.0 mercruiser 140hp with a 2 barrel rochester

 

[Bt Doctur]

Re: Mercruiser not running---still

Where and how are you checking for spark? firing order 1-3-4-2

 

[Coors]

Re: Mercruiser not running---still

wet plugs don't like to fire-clean or replace?

 

[jedimaster]

Re: Mercruiser not running---still

1342 no problem, how do you know for sure what distrib post is number 1? any easy way the distributor is not marked. I am pretty sure its ok, since the wires never came off from last year when it was running.
Perhaps a little diagram or something on the web?

 

[jedimaster]

Re: Mercruiser not running---still

Maybe take this picture and put an arrow onto the one that is number one?

 

[jedimaster]

Re: Mercruiser not running---still

Also anyone have a carb rebuild instruction pdf or something for the 2 barrel rochester? I am sure I can fidle my way through it but instructions never hurt. The shop manual I have is up at the cottage and the boat is at home in the driveway with me about 300 miles away from each other.

 

[bjcsc]

Re: Mercruiser not running---still

When you pull your plugs to clean them, put your finger over the #1 plug hole and turn the engine by hand. When the timing mark comes around to TDC and you feel pressure pushing air past your finger, stop at TDC. Whatever terminal your rotor is pointing to is #1.

 

[goblenick]

Re: Mercruiser not running---still

Also anyone have a carb rebuild instruction pdf or something for the 2 barrel rochester? I am sure I can fidle my way through it but instructions never hurt. The shop manual I have is up at the cottage and the boat is at home in the driveway with me about 300 miles away from each other.

Did your rebuild kit not come with the instructions? I'll scan it out of my manual and post it if no one else has by the time I get off work tonight.

 

[jedimaster]

Re: Mercruiser not running---still

I don't know it may, I havn't picked it up yet. Still at work.

 

[whywhyzed]

Re: Mercruiser not running---still

If the carb were the problem, pouring a little bit of fuel down the throat and then cranking the engine - it will start.
If it doesn't start like that, rebuilding the carb is a waste of time.
3.0's are not finicky starting engines.
If they have fuel, air and a spark somewheres between 15 BTDC and 5 ATDC , they kick and go.

 

[jedimaster]

Re: Mercruiser not running---still

Well I am sure the carb needed to be rbuilt anyway, but what else do you think it would be? The carb kit has the instructions.

 

[Coors]

Re: Mercruiser not running---still

he has already fouled his plugs, no more gas is needed.

 

[jedimaster]

Re: Mercruiser not running---still

Fixed.......

wasn't the carb
wasn't bad gas
wasn't misaligned spark plug wires
wasn't timing
wasn't the blown head gasket...although that needed to be fixed.

Broken ignition kill switch wire

The thing I don't get is why did I have spark but it wouldn't run? Does the kill switch wire just restrict voltage or something, but still allow spark?

 

[Don S]

Re: Mercruiser not running---still

HOW, (in detail), did you check for spark?

With a broken wire to the kill switch there is no way you could have spark.

Now, if you have a points system, with the resistor bypass wire, you will have power to the coil while cranking only. But it should have fired and started, but died when you let off the key.

 

[jedimaster]

Re: Mercruiser not running---still

Its a points system, and would not run and die, just wouldn't fire at all.
I took all the plugs out and rest them on the block and cranked it over and looked at them for spark.
I also have an inline lightup spark tester and it lit up while cranking.

 

[Don S]

Re: Mercruiser not running---still

You may have bright blue spark, but is the dwell and timing anywhere close?
Back to the firing order. Is it correct, Is the firing order actually starting at #1 TDC. A flooded condition will not allow the plugs to fire.
If the engine is not turning fast enough, it won't start or even sound like it's going to start.
You have put gas in the carb and it still wouldn't fire. Sounds to me like you need to find a real mechanic to have a quick look.

 

[jedimaster]

Re: Mercruiser not running---still

I dunno, but it is running and purring like a kitten.
All I know is when I found that wire from the kill switch was broken it started up instantly. I thought it was very odd even though there was spark at the plugs. Firing order was fine as I mentioned. Timing also was fine. dwell was fine. Everything was as it was from last year when it got stored. The only thing I found was a wire got broken near the kill switch on the throttle. As I said odd that there is spark when cranking with the kill switch wire broken. Anyway. Its working. thanks for everyones time and thought.

 

[180shabah]

Re: Mercruiser not running---still

Glad it's running, but "that don't make no sense!"