1984 Mercruiser GM 350 engine no start, not even trying to fire

[sdowney717]

Beginning to wonder if valves are stuck open.
Engine is portside, so should be standard rotation.
Distributor turns CCW, is that correct?
And what is the firing order? 1-8-4-3-6-5-7-2 ?

What is compression range for GM 350 MCIE 260 Mercruiser?
What is the spark timing?
I pulled wires and took off cap and everything looks ok, the rotor does not come off.
I static timed by putting cyl #1 at 8 degrees BTDC and turned distributer till it fired the spark.
I did all that after it has continually refused to fire.

History of engine is owner badly flooded engine to the point of the oil level rose way high on dipstick when he was trying to start up, and he burned out the starter. That problem was caused by needle valve in quadrajet laying in float chamber. I repaired the carb, no more flooding. Oil changed, and now no fire, no start. Appears to have very good spark. We changed the spark plugs. Other observation is when cranking some gas is thrown up out of the carb from the intake manifold Stuck intake valves??

Pulling spark plugs and they are dry. Beginning to wonder is engine has lost compression due to intake valves stuck open.
Plan to check engine compression next

 

[Scott Danforth]

What are your compression numbers?

Do you have points, if so service them

 

[sdowney717]

Will check the compression in a few days.
It has electronic ignition, no points.

So is this a standard rotation engine?
Distributor turns CCW

 

[Scott Danforth]

Will check the compression in a few days.
It has electronic ignition, no points.

So is this a standard rotation engine?
Distributor turns CCW

yes, its a standard rotation.

go to the stickies, follow the Thunderbolt Ignition troubleshooting guide.

 

[sdowney717]

yes, its a standard rotation.

go to the stickies, follow the Thunderbolt Ignition troubleshooting guide.

What about the distibutor rotation, everything I see online has it turning CW, this one is turning CCW.
The starter was replaced as it burned out when he flooded the engine.
Maybe it is wrong rotation starter?
Starter gear drive faces bow, brush end faces stern, and it mounts behind the engine

If you stand in front of the engine (like if you could), facing it, the engine pully turns CW when cranked by starter

 

[Bt Doctur]

A aft mounted starter like for a inboard? If Yes, starter rotation is just the opposite of engine rotation. All gm dist turn clockwise even the reverse rotation engines. So if Aft entry, a standard rotation motor uses a reverse rotation starter and a reverse rotation motor uses a standard rotation starter.
Easiest way to firing order is find #1 and use the standard firing order going in a CCW rotation. This will leave you with the correct firing order for a reverse rotation motor
1,2,7,5,6,3,4,8

 

[sdowney717]

A aft mounted starter like for a inboard? If Yes, starter rotation is just the opposite of engine rotation. All gm dist turn clockwise even the reverse rotation engines. So if Aft entry, a standard rotation motor uses a reverse rotation starter and a reverse rotation motor uses a standard rotation starter.
Easiest way to firing order is find #1 and use the standard firing order going in a CCW rotation. This will leave you with the correct firing order for a reverse rotation motor
1,2,7,5,6,3,4,8

I did try switching wires around, BUT, big but, no one had messed with the spark plug wires, or distributor timing and it refused to fire up, so none of that made any sense me changing things around.

The Rotor is most definitely turning CCW on this engine, a GM 350 Mercruiser MIE 260, and if it is not supposed to turn CCW, of course nothing will make it start as it is connected also to the camshaft which would be turning the wrong way too.

HOW DEFINITIVELY do people agree with the distributor supposed to spin CW? Must mean the wrong starter was put on the engine. Is your knowledge like 100% about this distributor rotation issue? NONE of them Mercruiser GM 350 engines did spin CCW in 1984?

 

[sdowney717]

Parts list for starters on this engine mention LH and RH starters.
Meaning Distributor would have to turn either CCW or CW depending on which starter is used. Unless the blocks differ among mie 260 motors.
Dont get why they would list LH and RH starters, if all GM distributors turn the same CW direction? Unless they do something inside the motor, timing gears vs timing chains?
https://www.marineengine.com/parts/.../5907058-thru-0b522505/starter-and-alternator

 

[Scott Danforth]

If you have an I/O you have a standard rotation motor PERIOD

Only with pure inboards were RH and LH motors used, and only when twins

 

[sdowney717]

If you have an I/O you have a standard rotation motor PERIOD

Only with pure inboards were RH and LH motors used, and only when twins

of course, they are inboard.
How about distributor rotation?

 

[Scott Danforth]

of course, they are inboard.
How about distributor rotation?

Cam, oil pump and distributor rotate the same regardless of RH vs LH. Clockwise.

LH motors have a timing chain where cam and crank rotate same direction.

RH motors have timing gears where Crank turns RH and the cam turns LH. the distributor and oil pump still turn Clockwise

 

[sdowney717]

I realized the situation is pretty definitive, the distributor turns the oil pump, distributor then MUST turn CW or the oil pump wont pump oil. So he has the wrong rotation starter installed.
The Velvet drives 1.88-1.91 gear reduction units spin the output prop shaft opposite engine rotation. So he must have that gear ratio velvet drive that reverses shaft rotation from engine rotation.
He will need a new CW starter

 

[sdowney717]

Does this mean the firing order is then

https://www.crankshaftcoalition.com/wiki/GM_firing_orders

1-2-7-5-6-3-4-8
since it is a RH reverse rotation motor

 

[dubs283]

1-2-7-5-6-3-4-8
since it is a RH reverse rotation motor

Yes, that is the gm sbc counter rotated (rh) engine firing order.

Just came to say on most twin inboard engine set ups the standard (lh) rotation engine is the port engine. Stbd engine is counter rotated (rh).

Not saying that it what you have or that you are wrong. 1984 was a while ago and most boats of that vintage have had the engine out at least once. No telling who/what/when anything non oem has happened to your boat. Unless you've owned since new?

Mercury would have included firing order on the engine info tag, either on a valve cover or the rain hat

 

[sdowney717]

Yes, that is the gm sbc counter rotated (rh) engine firing order.

Just came to say on most twin inboard engine set ups the standard (lh) rotation engine is the port engine. Stbd engine is counter rotated (rh).

Not saying that it what you have or that you are wrong. 1984 was a while ago and most boats of that vintage have had the engine out at least once. No telling who/what/when anything non oem has happened to your boat. Unless you've owned since new?

Mercury would have included firing order on the engine info tag, either on a valve cover or the rain hat

I found out some ratio velvet drives change engine rotation to the prop.
1.88 to 1.81 gear reduction units do that. Input is RH, and output is LH
the engine must be a RH reverse rotation as the distributor cannot turn CCW cause the oil pump driven by the distributor wont pump any oil.

RH and LH engines change rotation but keep distributor turning the same way by using either timing gears or a timing chain.

Even though I knew all that, it is still a re-learning experience. You tend to forget stuff when you dont deal with it all the time.

 

[dubs283]

The orientation of the pump in the velvet drive changes the rotation of the transmission/output for fwd/rev

The cut of the gears on the distributor/camshaft is how the rotation of the distributor shaft is maintained to be the same for lh and rh rotation engines.

Ford did the same thing on their 335 series engines

 

[Rick Stephens]

A manual would be really handy. Wonder if there is one available? Fascinating figuring it out.

 

[dubs283]

Ford did the same thing on their 335 series engines

Erp......correction

Windsor/small block engines, not 335 series....

 

[tank1949]

Did you do compression test?

 

[sdowney717]

Did you do compression test?

No, likely wont bother. engine is confirmed turning the wrong way, as in LH when needs to be RH. I don't want to do extra work. Plus it explains why when I removed some pugs, they were totally dry and clean, even after spraying in start fluid and a little extra gas. The intake manifold blew the gas back out the carb, spitting it out when cranking over cause it was acting like the exhaust side. When distributor turns CCW, since it also turns the oil pump, then engine wont be having any oil pressure, and that is incompatible with life.