1969 merc 1250 prob

[slim6969]

hello all i just got a 1969 merc 125 hp i can get it started but once started it seems to run full throttle (or close to it ) the floats are not stuck the linkage is good the carburetor function as they should i did see some or the wires have dry rot would this cause the motor to run really fast if they were touching somewhere i have added a pic so you can see what im talking about Thanks

 

[Faztbullet]

Re: 1969 merc 1250 prob

No only timing or carb/fuel issue will cause high idle.....

 

[andrewddrennon]

Re: 1969 merc 1250 prob

Have you tried moving the distributor back to the idle stop by hand? Idle stop may be screwed way in? Your sure synk and link is good?

 

[slim6969]

Re: 1969 merc 1250 prob

Have you tried moving the distributor back to the idle stop by hand? Idle stop may be screwed way in? Your sure synk and link is good?

I will take a look tonight and post my findings thanks for the replys

 

[slim6969]

Re: 1969 merc 1250 prob

I will take a look tonight and post my findings thanks for the replys

so it seems that the distributor can turn closed more then the plate in the back of the carbs if i turn it with the carbs closed i could turn it maybe a 1/8 of a turn does this mean anything ? also i did see that the top carb was 1/8 open when the other 2 are fully closed i rest it and it now is closed with the others would 1 carb being 1/8 open when it should be closed make it rev way up on start up ? thanks for all the help

 

[andrewddrennon]

Re: 1969 merc 1250 prob

Yes you are supposed to get timing advance before you start getting more fuel. It is supposed to do that. You need to synk the throttle plates. Part of your fast idle problem id say.

The throttle plates should all be completely closed at idle and flat horizontally at wide open. Each carb will have a single small bolt on the butterfly. Loosen the three bolts when you have the throttle pushed against the idle stop. Then simply retighten them when each carb is closed. Sounds to me like you need to go through all the lynk and sink on that motor.

You should try to get a manual.

 

[slim6969]

Re: 1969 merc 1250 prob

Yes you are supposed to get timing advance before you start getting more fuel. It is supposed to do that.

alright thanks i really know nothing about boat outboards but i am good at tinkering i guess most of the time i get lucky lol im going to put it all back together and start it up and see what happens if it still runs fast what kind of tests should i do before ripping it back apart ?

 

[andrewddrennon]

Re: 1969 merc 1250 prob

I edited my earlier post.... reread it.

 

[andrewddrennon]

Re: 1969 merc 1250 prob

Honestly i dont think there is any reason to take anything apart yet........ you need to do a synk and link which is purely adjustment.

 

[slim6969]

Re: 1969 merc 1250 prob

Honestly i dont think there is any reason to take anything apart yet........ you need to do a synk and link which is purely adjustment.

thanks for all the replys i will keep plugging away at it and i will be getting a manual because it would seem i am way over my head with this one

 

[slim6969]

Re: 1969 merc 1250 prob

so just an update i cleaned the carbs and did a lynk and sink and now it runs really good took 5min to start it the first time after all that but once warm it starts every time with little cranking so thank you all for your help

 

[CharlieB]

Re: 1969 merc 1250 prob

The old Merc are kind of tough to start cold, they REALLY LIKE a LOT of choke on the first start of the day.