Jump to content

Mercruiser 120 specs 1964- 72 Gm

FishingTheFL

FishingTheFL
in This Old Boat

 Share

Recommended Posts

Shellback

Shellback

Posted
Posted

So he has the plugs right in picture I posted.

Sent from my XT1528 using Lake Ontario United mobile app

Your picture in post #34 shows the firing order is correct. But as rolmps stated, your #1 position has to relate to where the rotor is pointing when the engine is at top dead center on the compression stroke. If you bring the engine to TDC and the rotor is not pointing at #1, you can move #1 wire to the position the rotor is pointing, then plug in #3, #4, and #2 following #1 in a clockwise direction. 

Link to comment
Share on other sites
Shellback

Shellback

Posted
Posted

In an earlier post, you listed the point gap at .022. Set the points at that, and don't worry about the dwell. That 4 cyl, point ignition, carb motor is about as basic as you can get. Engine TDC on compression stroke, rotor pointing at #1 wire, firing order correct, and it's getting gas, you should only have to adjust the distributor timing a little as it cranks, then it should run if the cam and lifters were installed properly. Once started and running, set the timing with a light.

Link to comment
Share on other sites
FishingTheFL

FishingTheFL

Posted
  • Author
Posted

Let's say he had everything with the timing right. Black ash like material was coming out of the exhaust and floating on the surface. I'm going to put it back the way he had everything and put muffs on it see if its still doing it. Could it be the carb messed up? He said it seemed like it was getting to much fuel. If I remember right he adjusted the carb but it made no difference

Sent from my XT1528 using Lake Ontario United mobile app

Link to comment
Share on other sites
Shellback

Shellback

Posted
Posted

Yes the carb could be messed up. Did he have it off when he did the cam job? If it was upside down or sideways, it could have effected the float. I don't see a reason to have the carb off doing the cam though, and think it's unlikely to be your problem, but you can't rule it out. Personally if everything was right with the distributor timing and firing order, I'd start thinking about valve adjustment. Could some be set too tight? That will cause a problem for sure. 

Link to comment
Share on other sites
Shellback

Shellback

Posted
Posted

67374456f0f313f8cf6c4ecfec18fb6f.jpg

df326838296c314edf4b3aa0d2f5653a.jpg

Sent from my XT1528 using Lake Ontario United mobile app

At tdc

Also the rods can still be twisted. Thought they were suppose to be tightened till they couldn't twist any more and then add 3/4 turn?

Are you speaking about the pushrods for the valves? I've always adjusted them with the engine running. Back off the nut till they start clacking, then tighten till they stop and add a 1/2 turn or so. The pushrods should still rotate when adjusted properly.

Link to comment
Share on other sites
stoneam2006

stoneam2006

Posted
Posted

So I just started it up... Turned the distributor ccw around 45*... Now it runs beautifully... Idk what the deal is... Didn't touch the lash just took the cover off... Fired it up... Turned distributor... Bam...she runs. Gave her gas right up to 40k.

Sent from my XT1528 using Lake Ontario United mobile app

Awesome I am glad to hear that

Sent from my SM-N920V using Tapatalk

Link to comment
Share on other sites
L&M

L&M

Posted
Posted

So I just started it up... Turned the distributor ccw around 45*... Now it runs beautifully... Idk what the deal is... Didn't touch the lash just took the cover off... Fired it up... Turned distributor... Bam...she runs. Gave her gas right up to 40k.

Sent from my XT1528 using Lake Ontario United mobile app

 

Nice to see you got it running, but you'll be replacing more than a cam if you keep running that up to 4k with no load on it . Just sayin ;)

Link to comment
Share on other sites
rolmops

rolmops

Posted
Posted

Now after a few tries to make sure it was good... Won't fire... Improperly gapped maybe? Would switching this to electronic ignition get rid of the issue... Seems this could be simply but not really lol

Sent from my XT1528 using Lake Ontario United mobile app

Check for a loose wire

Link to comment
Share on other sites
Xxx

Xxx

Posted
Posted

When you go to time it make sure your rpm's stay below 650, if when timing it if it starts to gain rpm's keep backing the idle screw out to bring the rpm's below 650. You do this to keep the mechanical advance out of the scene, time her up to specs and lock the distributor down. The mechanical advance works with the rpm's of motor. If you did the timing say at 800 rpm the mechanical advance would be advancing the timing already then you would be off, say retarded at the whole rpm range because it already had advanced it's self. Sound like you got'er licked. Now you got a hell of an education, one you won't forget!!! LOL

Link to comment
Share on other sites
FishingTheFL

FishingTheFL

Posted
  • Author
Posted (edited)

I forgot to lock the distributor down... I'm going to repeat everything I did today. The rpms where closer to 1000 when I get it running. Take it to reduce the rpms I gotta mess with the carb?

I'm definitely getting a crash course on mechanics. Now I just need to buy the tools lol. Got a timing gun last night.

Sent from my XT1528 using Lake Ontario United mobile app

Edited by FishingTheFL
Link to comment
Share on other sites
Xxx

Xxx

Posted
Posted

Yes

Sent from my XT1528 using Lake Ontario United mobile app

X2 !! I have a wrench that's bent like off set right then strait for about a foot or more then offset left if I remember right there 9/16 box end. It helps having a whole snap-on box given to you from my father who's of 30 + years being a mechanic,

Link to comment
Share on other sites
Xxx

Xxx

Posted
Posted

Great to hear it's running, but not good on the knock. Don't forget that washer/shim isn't in there, maybe your sound could be coming from that? Or is the sound more deep and lower. Like a wrist pin or a bad bearing,, I'm pulling for ya bud!!!

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing
×
×
  • Create New...