73 Merc 1150 6cyl inline (no start)

[stbiblecg]

Ok, I have just re-built all 3 carbs, the fuel pump, water pump, new ignition coil 725 cold cranking amp battery, new fuel lines, new shaft and rotor inside distributor, new cap, new wires, new plugs, and had a tech ensure all wiring was correct on my 1150 thunderbolt ignition. She will not start, if i spray fuel in the carbs through a squirt bottle hold idle rev up and hold choke down she will try and try almost firing every time she cranks for maybe one second after i let the key off then dies. I printed the link & sync out for my engine specifically and the front of the engine says on it what degrees it should be....just wondering if anyone has any step by step for timing this thing to advance or slow the spark or any info at all. Someone told me something about taking all the plugs out putting a dial indicator in #1 on tdc and zero the dial, turn flywheel back 1/2 inch then forward to whatever degrees the engine say's on it, then move the timing mark to match that number on the flywheel. then something about taking throttle off put timing light on #1 and doing something any better instructions or any help on ensuring the timing and spark is set right? Thanks for any help!

Tim

 

[stbiblecg]

Re: 73 Merc 1150 6cyl inline (no start)

ok well just went out and check compression all cylinders have 110psi except 1 has 30 and 5 has 90 any suggestions or ideas or places to get parts to rebuild it

 

[Moody Blue]

Re: 73 Merc 1150 6cyl inline (no start)

Wow, that's alot of time and money into that motor. You didn't check compression before starting all that work?

Is this a new motor to you, or one that just recently stopped running?

Carbs rebuilt or just cleaned?
Float levels set properly in the carbs during rebuild?
All plugs and fittings removed, soaked then blown out with compressed air?

Verified spark at plugs?

What tech verified the wiring was correct? What was replaced or changed?

There is an excellent write up on the link & sync procedure here

http://forums.iboats.com/showthread.php?t=168855

As for verifying TDC for timing purposes, remove plug #1 and insert dial gauge. Turn flywheel by hand (key OFF and battery disconnected) until #1 piston reaches TDC. Verify that the timing mark on the flywheel lines up with the TDC mark on the timing decal.

 

[stbiblecg]

Re: 73 Merc 1150 6cyl inline (no start)

yes everything was done correctly david something was the mercury tech at port milford ct, been workin on merc for 40 yrs replaced some wires that were old carbs were rebuilt everything was done right i am a mechanic spark good did you read my second post

new motor to me and the compression did get tested when i bought it but i guess it went during all this time cranking must have been one of those freak things were the guy sold it at the right time

 

[merc850]

Re: 73 Merc 1150 6cyl inline (no start)

Okay true story--- I bought a Merc 85 last year and this year I put it on a boat, I timed the arrows to the dots on the flywheel and even replaced the timing decal and turned that motor over for a long time and once it backfired thru the exhaust, that's all. Then I stuck a pen in #1 and found TDC and the timing dots were off , someone had taken the flywheel apart and reassembled it 230* out of synch
It started great after I fixed it. Never assume PO's know anything!

 

[merc850]

Re: 73 Merc 1150 6cyl inline (no start)

PS there were socket marks on the hub paint, that should have been a dead give away!

 

[Chris1956]

Re: 73 Merc 1150 6cyl inline (no start)

Tim, Remove the spark plugs and using a screwdriver, set the top piston to top dead center. On the '73 models, the timing marks are on the cowl support. The timing decal and the timing mark on the cowl support should match. If not, the outer flywheel is installed improperly, and must be realigned.

Make sure the cast arrow on the distributor pulley points to the punch mark on the flywheel. Adjust the timing belt to make it so.

You will need to choke the heck out of her for it to start when cold.

 

[stbiblecg]

Re: 73 Merc 1150 6cyl inline (no start)

Everyone is skipping over my second post that the engine is done all cylinders have 110psi except 1 has 30 and 5 has 90.......i'm screwed

 

[Dave1027]

Re: 73 Merc 1150 6cyl inline (no start)

It seems you are screwed but I don't understand how two cylinders lose compression from cranking? I would think the battery would go first. Besides, the problem precipitated the cranking, right?

I think you better double check your compression test making sure you have a perfect seal in the spark plug hole. Maybe you have stripped spark plug hole threads?

 

[stbiblecg]

Re: 73 Merc 1150 6cyl inline (no start)

well i have been cranking it after every new part since i bought it 3 4 months ago so the battery has gone dead plenty of times. But no i did the ole soapy water test on the holes the same time i was checking compression

 

[Moody Blue]

Re: 73 Merc 1150 6cyl inline (no start)

compression did get tested when i bought it but i guess it went during all this time cranking must have been one of those freak things were the guy sold it at the right time

He sold it at the right time alright, when it was time for a rebuild .

 

[freshness247]

Re: 73 Merc 1150 6cyl inline (no start)

When you say you have "new wires" does that include the Trigger and Stator wires?

I had a similar problem with my '77 850 not starting about 3 years ago. Mechanics wanted to write it off as the "reed valves". I disagreed as my Dad purchased this motor brand spankin' new in august of '76, all maintenance, garage kept etc has been done. Never once had a problem with this motor up to that point.

Changed the Trigger and Stator wires and, according to dad, it has ran "better than new" since.

However, now, 3 years later and we're experiencing a rough idle around 700-1500rpms, but runs perfect after that. So we're working through that problem now.

 

[ChrisfromVT]

Re: 73 Merc 1150 6cyl inline (no start)

There's absolutely no need to troubleshoot anything else until you figure out your compression issue which you should know since you say you are a mechanic. Did you think to have your merc mechanic test run it for you after doing all that work?
Enjoy the new anchor!