Almost No Compression ?

[AshleysRevenge]

I've got a 1983 merc 260 5.7l v8. Alpha 1 gen 1.

Had a hole rot through my intake manifold in july. I finally got every thing put back together and can't get it started. So I started from scratch and did a comp test.
#1 0 psi
#2 0 psi
#3 30 psi
#4 30 psi
#5 0 psi
#6 60 psi (after a few extra cranks since I saw it was at least holding and gaining psi)
#7 0 psi
#8 0 psi

Now ether I don't have a clue and forgot how to do a comp test or worse I totally screwed something up putting the new intake back on. I do have the manual for the motor from this site but would love some suggestions on what I've done wrong.

One other thing...

Upon putting the intake back on, with the distributer out the motor got turned over. I followed the procedure for getting that back to where it needed to be but in the process the motor was turned backwards to get TDC (just a little). Which now I read in the manual that little bit can destroy the water pump in the stern drive. I only bring this up because it would seem now that my stern impeller or water pump is not functioning on muffs. Is there a way to check the impeller with out taking the stern drive apart? I've also replaced the log type exhaust manifold and riser on the starboard side during all of this.

Thanks again all

David

 

[AshleysRevenge]

Okay, sorry With muffs water is not making it into the engine. Or even to that thing under the exhaust manifold on the starboard side that has a line running to the power steering. I can hook a hose up there and get water to come out the exhaust but nothing from the muffs to the motor.

 

[alldodge]

I've got a 1983 merc 260 5.7l v8. Alpha 1 gen 1.

Had a hole rot through my intake manifold in july. I finally got every thing put back together and can't get it started. So I started from scratch and did a comp test.
#1 0 psi
#2 0 psi
#3 30 psi
#4 30 psi
#5 0 psi
#6 60 psi (after a few extra cranks since I saw it was at least holding and gaining psi)
#7 0 psi
#8 0 psi

Now ether I don't have a clue and forgot how to do a comp test or worse I totally screwed something up putting the new intake back on. I do have the manual for the motor from this site but would love some suggestions on what I've done wrong.

One other thing...

Upon putting the intake back on, with the distributer out the motor got turned over. I followed the procedure for getting that back to where it needed to be but in the process the motor was turned backwards to get TDC (just a little). Which now I read in the manual that little bit can destroy the water pump in the stern drive. I only bring this up because it would seem now that my stern impeller or water pump is not functioning on muffs. Is there a way to check the impeller with out taking the stern drive apart? I've also replaced the log type exhaust manifold and riser on the starboard side during all of this.

Thanks again all

David

Tell us more about the hole in the intake and was any rust involved?
What kind of compression gauge are you using and you are putting it in the spark plug hole, right?

As for the impeller, only way to be sure is to separate the drive and look

Why the exhaust manifold only on the starboard side?

 

[AshleysRevenge]

No Title

Starboard side because the bolts that held the riser on were leaking rust and salt water all over the starter solenoid and starter. I figured if the intake went it was probably time for what was also showing signs. AND there Expensive!

Photo of comp tester and yes I am screwing them all the way in (all meaning every cylinder). Turning over enough times to get a good reading.

Hole just by (I think) the water temp sensor and bolt.

BTY the rust all over the intake was not from the engine, this thing has been sitting out for a month and a half now. I don't even know why I still have it.

 

[alldodge]

With all reading that low my first thought is, are the rockers and valves working? Nothing else was done other then replacing the intake?

 

[Bondo]

Ayuh,..... Take the spark plug end of yer tester, 'n screw it into a cylinder,...
Bring That cylinder to Tdc, hold the crank, 'n apply 50 psi or so, then follow the sound of excapin' air,.....

Yer tester may, or may not have a tire valve in that end,... if so, take it out,....

Sounds like ya mighta had too much saltwater where it shouldn'ta been, for too long,.....

 

[AshleysRevenge]

All the rockers, push rods, and springs were replace at least 3 to 4 outings before this intake thing happened.

# 8 intake spring was broke and crushed
# 3 exhaust spring was broke and crushed
# 5 ? was the same

This was back in May/June this year when she was running rough and a comp test showed #8 was way out from the rest of the cylinders. #3 and #5 were just found while replacing every thing with out pulling the heads.

#7 exhaust stud pulled out and I had both exhaust and intake studs replaced at a machine shop (while the heads were still on the boat)


? Could my valves be stuck open? From rust. The valves were all working beautifully before this happened. The motor has not run since July 13, 2014

 

[AshleysRevenge]

Any thing suggested tonight here I will do tomorrow. Like putting air into the cylinder.

That being said, here is something. With the starter turning the motor over, when stopped you can hear a clicking/tapping sound coming from the motor, like pressure is stuck and trying to leak out or something like that. This was not so before July 4th. This is with plugs in or out

 

[alldodge]

All the rockers, push rods, and springs were replace at least 3 to 4 outings before this intake thing happened.

# 8 intake spring was broke and crushed
# 3 exhaust spring was broke and crushed
# 5 ? was the same

This was back in May/June this year when she was running rough and a comp test showed #8 was way out from the rest of the cylinders. #3 and #5 were just found while replacing every thing with out pulling the heads.

#7 exhaust stud pulled out and I had both exhaust and intake studs replaced at a machine shop (while the heads were still on the boat)


? Could my valves be stuck open? From rust. The valves were all working beautifully before this happened. The motor has not run since July 13, 2014

Yep, that would be my guess.

You did all this work without pulling the heads? If this is the case then there is rust everywhere and needs a full rebuild or replacement

 

[achris]

Sounds like you may have screwed the rocker bolts down too tight. I would redo the valve adjustment. As for turning the engine backwards screwing up the impeller. You must be reading a seloc :facepalm:, because that's not in any Merc manual. In fact the procedure for re-installing the drive is to be turning the propeller backwards with the drive in forward gear. That turns the impeller backwards... And doesn't do a single negative thing to the impeller. As for not getting any water up to the engine with the muffs on... That is also correct for when the engine's not running. When the impeller is not turning, the vanes block the flow between the water inlets and the pump outlet. If you had water running up to the engine without the engine running, you'd have a bladeless impeller.

As for sitting for 'so long', I've been away since 26 June, and my engine hasn't turned in that time. It's also winter here (read 'cold and wet'), and I expect that when I do eventually get the boat wet, the engine will fire straight up.... Unless you had water sitting in all the cylinders, sitting for 'so long' is not the source of your problem....

Chris......

 

[AshleysRevenge]

Thank you Chris, I'll be back to let y'all know how it goes

 

[Grub54891]

Try a different comp tester,had the same issue,and the valve on the tester went bad. Replaced it with a tire valve and still did not work. Got a valve from snap on,works like new!

 

[AshleysRevenge]

Okay so far from air tests the valves are not closing. I'm guessing rust. Every valve moves smoothly some close and most don't. I think it is not the end of the world yet and if I could just get it running for a bit and change the oil 2 or 3 times, she'll clean her self up.

I replaced the ignition mod/amp, it was definitely dead.
Replaced the coil, not yet sure if I needed to do that yet

Problem with this now is not having spark. Now before you get started I have done the diagnostic step by step, albeit vague.
Specifically when you get to step
Remove Hi-Tension Lead
from Dist. to Coil.
Insert a Spark Gap from
Coil Tower to Ground
Remove WHT/GRN Lead from Dist. Terminal – Ignition Key in Run Position. Strike the Terminal on the WHT/GRN Lead Against Ground




What why/grn? The one coming from the dist. or the one coming from the ignition mod/amp?

IF it is the ignition then yes I do have spark... and then should replace the sensor in the diet?
If it is the wire from the diet then no I don't have spark

 

[alldodge]

Okay so far from air tests the valves are not closing. I'm guessing rust. Every valve moves smoothly some close and most don't. I think it is not the end of the world yet and if I could just get it running for a bit and change the oil 2 or 3 times, she'll clean her self up.

I replaced the ignition mod/amp, it was definitely dead.
Replaced the coil, not yet sure if I needed to do that yet

Problem with this now is not having spark. Now before you get started I have done the diagnostic step by step, albeit vague.
Specifically when you get to step
Remove Hi-Tension Lead
from Dist. to Coil.
Insert a Spark Gap from
Coil Tower to Ground
Remove WHT/GRN Lead from Dist. Terminal – Ignition Key in Run Position. Strike the Terminal on the WHT/GRN Lead Against Ground




What why/grn? The one coming from the dist. or the one coming from the ignition mod/amp?

IF it is the ignition then yes I do have spark... and then should replace the sensor in the diet?
If it is the wire from the diet then no I don't have spark

Your just pulling our leg right, just having a little fun :frusty:

 

[Bondo]

Your just pulling our leg right, just having a little fun :frusty:

Ayuh,.... Just douse everything with WD-40, 'n she'll be Just Fine,..... ,.....

AR,.... Ya gotta pull yer motor,....

Ignition ain't no good without compression,... She's got Much bigger problems right now,....

 

[achris]

Remove WHT/GRN Lead from Dist. Terminal – Ignition Key in Run Position. Strike the Terminal on the WHT/GRN Lead Against Ground [/FONT]

What why/grn? The one coming from the dist. or the one coming from the ignition mod/amp?

IF it is the ignition then yes I do have spark... and then should replace the sensor in the diet?
If it is the wire from the diet then no I don't have spark

I'll ignore everything else the others have already commented on... The Wht/Grn is the wire that gives the signal TO the ignition amplifier, so when you do the test it needs to be still connected to the amplifier, so remove it from the distributor. BTW, did you check for 12 volts on the Wht/Red wire? If there is no 12v, then the sensor in the dist can't switch the Wht/Grn wire. Also make sure the amplifier and the dist body are BOTH grounded properly. Again, if the ground on either is 'resistive', you can lose spark. If you don't have a wire from the dist body to the engine block, put one on.... Same goes for the amplifier....

Chris......

 

[AshleysRevenge]

My sensor in the diet was bad. Now the coil, amp, cap, rotor and sensor have been replaced. Do you think it matters that I replaced a V8-24s with a V8-22a?

I almost burned the new starter up last night. It wants to start but like bondo said ignition with out compression, I've got nothing. I am starting to except the fact that my end of season was back in july and I should probably start now to be ready for next spring. I don't know about pulling the motor (out of my league at the moment) but I can pull every thing else along with the heads for now. I at least have that much confidence.

It did sit too long with too much salt water where it shouldn't be. To me it sounds like I am about to do an overhaul or should I be looking for a new motor? That scares me too.

 

[Bondo]

My sensor in the diet was bad. Now the coil, amp, cap, rotor and sensor have been replaced. Do you think it matters that I replaced a V8-24s with a V8-22a?

I almost burned the new starter up last night. It wants to start but like bondo said ignition with out compression, I've got nothing. I am starting to except the fact that my end of season was back in july and I should probably start now to be ready for next spring. I don't know about pulling the motor (out of my league at the moment) but I can pull every thing else along with the heads for now. I at least have that much confidence.

It did sit too long with too much salt water where it shouldn't be. To me it sounds like I am about to do an overhaul or should I be looking for a new motor? That scares me too.

Ayuh,.... In all honesty, a reman Long Block is yer Best, 'n probably Cheapest way out,....

To pull the motor,....
Pull the Drive off,....
Disconnect at the wirin', 'n plumbin' to the motor, then lift straight up, 'n out,....

 

[AshleysRevenge]

No Title

Rust it is.

Look at number 8 exhaust. It's stuck at least 1/8" open. These heads will be in the shop tomorrow, maybe I'll get them back in a week.

Nothing but the bolts and stern drive left to pull the motor and send it to the shop.

Thank you all for all the motivation, I wouldn't have done this on my own.

Do you think I should start a new forum to let you all know how this turns out? Or just post back here in a week or so?

 

[achris]

If it's the same topic and an 'update', right back here would be fine.