Next Step? 1150 1976 Mercury

A

adesoto

Cadet
Joined
Jul 23, 2007
Messages
29
Motor had been sitting for 2 years. I had an issue starting her up, had primed gas bulb nice and tight but when cranked no fuel/no fire... Sprayed some gas/oil mix into piston#1 and she fired. Alright, I was recommened to clean out and replaced the gaskets on all three carbs. Done.. Redid the fuel pump with the valve kit and water impeller,too. This is what happened next, moved warmup control up all the way, turned key, pressed the choke button and all she did what turn and turn and turn.. Looked over the warmup cable to see if it turned anything in the motor, nothing.. adjusted as best I could the cable and still no response. Went back to spraying some gas into piston#1 and she fire up and revs up since the warmup control was up.. starting easing the warmup control back and half way she starts to sputter and when I move the warm up control back to where it supposed to be she she stops running....? The only way to keep her running is if I have the warmup control half way or 3/4 engaged. Any idea what to do next??? Also something to is that when she begins to want to go if I have the choke pushed in (I'm guessing when this happens I didn't need to choke) the motor stops turnning and makes a funny squelling noise and also hear something spinning... I wait for the spinning to stop and she starts without the choke.. I know of a idle stop screen that I saw and I know each of the carbs have an idle mix screen but did not want to mess with anything until I was able to get someone's opinion on this..? (btw when running she peed just fine)..Also I noticed that I have no throttle stop screw...would this cause so issue too?

I know there's alot of question all in there but I all new to this and just trying to get her started up myself before paying the $70 shop per hour fee..
Thanks in advance for your assistance..
 
A

adesoto

Cadet
Joined
Jul 23, 2007
Messages
29
Re: Next Step? 1150 1976 Mercury

I did a compression check and each is within 120 psi.. Spark test have not done this but I know that each plug has spark because I checked it grounded it outside to the block.. How do you do I spark check?
 
diaric

diaric

Chief Petty Officer
Joined
Jul 8, 2006
Messages
532
Re: Next Step? 1150 1976 Mercury

spark usually tested with a fairly cheap spark tester, from auto stores. if your throttle stop screw is gone, then your idle might not be set and thats why it stalls out.
 
T

Tinlizzy

Petty Officer 2nd Class
Joined
May 7, 2007
Messages
121
Re: Next Step? 1150 1976 Mercury

You performed the spark check allready it seems :)

Now follow the timing/sync article.
 
Plainsman

Plainsman

Rear Admiral
Joined
Apr 2, 2006
Messages
4,062
Re: Next Step? 1150 1976 Mercury

Yes you need to get a stop screw

If you prime the bulb, and keep squeezing it, does fuel come out of the carb?

How did you set the mixture screws on the carb? Set them all to 1 1/2 from lightly seated.

hope that helps
 
C

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,102
Re: Next Step? 1150 1976 Mercury

That motor neds to have an idle stop screw, a throtle stop screw and a max spark adv screw, all on the plate above the distributor. They are all phillips head, stainless steel screws 1/4-20 X3". Put SS nuts on the screws and turn the nuts up to the philips head and then screw 'em into the holes in the plate. Th nuts are then backed off to lock te screws into place....

Your motor could very well be dying since the idel stop screw, which sets minimum idle speed is missing.

Oh yeah, if you do not have a manual, get one!
 
A

adesoto

Cadet
Joined
Jul 23, 2007
Messages
29
Re: Next Step? 1150 1976 Mercury

PLainsman- To answer your question, Yes, if I squezze the prime bulb and keep squeezing it after it's tight. Gas does come out of the Carbs.
I have not touched the mixture screws... Didn't know what to do with them..

Diaric: At first when the warm up lever was set high it wouldn't do anything. Not until I tighted the cable up (at the side of the motor, on the cable there's a copper look circle piece that I spun around to tight it up) the warm up lever set on high now rev's the engine up. Just couldn't set it back because the motor would die on me.

Chris: I have the max spark advance and Idle stop screw, just missing the throttle stop screw. If you adjust on the screws, are all the others going to need adjusting as well?

I have a manual but it's kind of hard to understand when your doing and looking at this for the first time.

Thanks for all your assistance guys. Much needed and appreciated.
 
C

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,102
Re: Next Step? 1150 1976 Mercury

Throttlestop screw protects the carb butterflys from the full force of the throttle cable, when you slam it down. You should install one, but is is the least necessary of the three. All are adjusted independently.

It sounds like you need to set the carbs idle mixture and the idle stop.

Look on this forum for the "Timing and synch of Mercury Inlines" post. It will give you a procedure to follow to get the carbs and timing correct.
 
A

adesoto

Cadet
Joined
Jul 23, 2007
Messages
29
Re: Next Step? 1150 1976 Mercury

Looking over the time and sync... I had a couple of questions..

Timing Event One - throttle pickup.
As the throttle is advanced, the spark timing advances toward TDC and then to before TDC. As the timing is just passing TDC what does this stand for?the (1st (minor)throttle pickup Also where is this?)should hit and start to open the carbs. Use the timing light. Adjust the tang or trigger screw to make this a reality. All of them are speced different, but if the 1st pickup hits at 3-4 degrees BTDC advance - you win. Use the timing light with a friend cranking it to complete this setting.

Also had a question, the Idle screw for each carb, how to I get to it if the front cover that has the switch box doesn't allow you much clearance? If I where to take that front part of.. I couldnt start it then?
 
C

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,102
Re: Next Step? 1150 1976 Mercury

TDC is Top Dead Center. It refers to the piston being all the way at the end of the stroke closest to the spark plug. 3-4 degrees BTDC is before TDC, and is where the carbs should just start to open.


The carb mixture screw is adjusted with a long flat blade screwdriver, either thru the front cowling support, or next to the front cowling support.

It sounds like the Link and Sync may be a bit foreign to you. I hope you have a manual.
 
You must log in or register to reply here.
Top