1982 Merc 50HP Carb Adjustments

[markhoekstra]

I just finished rebuilding both carbs on the 1982 Merc 50hp on my pontoon boat and have a couple of questions about adjustments.

1) I replaced the foam floats with new plastic ones. When I put them in, each sat differently in the carb. One was very high (about 1/2" above the carb bowl gasket) and the other was low. After adjusting both to the 1/4" above the bowl gasket as recommended in the service manual, I put them back int he engine and pumped the fuel ball. Gas started shooting out the front of the top carb (which was also the one that initially sat too high). I adjusted it to around 3/8" above the gasket. This fixed the problem. The engine runs fine now, but will this cause any problems that are not apparent?

2) I am not sure what the proper procedure is to adjust the linkage between the two carbs. The original one cracked so I installed a new one. I put the throttle in neutral, and then tightened the bolt on the lower carb. This way both carbs should have been in the same position since the spring shuts the inner butterfly. Again, the motor seems to run fine at idle and under load, but I want to be sure that the lower carb gets enough fuel (i.e. lubrication) when idling since it's a pontoon boat and I spend a lot of time at slower speeds.

Thanks to everyone else whose posts to this forum got me this far!

 

[Nippissinger]

Re: 1982 Merc 50HP Carb Adjustments

Hopefully a Merc mechanic is reading and can give you the step by step in linc and sync...I would suggest you get yourself a service manual to cover your engine. It will pay for itself in 1 repair...

You can try searching the forum for the method as different horses are diferrent methods of syncing..

Will

 

[markhoekstra]

Re: 1982 Merc 50HP Carb Adjustments

I have the SELOC Mercury OUtboards 1965-89 repair manual. It doesn't say anything about the carburator linkage setting. Is there a better manual out there?

 

[cell]

Re: 1982 Merc 50HP Carb Adjustments

) I replaced the foam floats with new plastic ones. When I put them in, each sat differently in the carb. One was very high (about 1/2" above the carb bowl gasket)

Looks like one float was sticking?Find out why it didn't drop as the other one.

I am not sure what the proper procedure is to adjust the linkage between the two carbs. The original one cracked so I installed a new one.

When you put the controls in neutral are both carbs closed the same amount?
when you put the controls all the way forward(engine off)do they open All the way,and at the same amount?

 

[markhoekstra]

Re: 1982 Merc 50HP Carb Adjustments

I think they seated differently because the spring on the upper carb was longer or something along those lines. It didn't seem to be stuck because when I pressed down, it sprang back up.

The linkage was secured when the lower was closed and the upper (controlled by the throttle) was in neutral. I am pretty sure that closes it, but not sure how precicely they need to be aligned.

 

[cell]

Re: 1982 Merc 50HP Carb Adjustments

I never seen a float that you install with spring down...tho I haven't seen a lot of things yet either...double check the install instructions.If your SELOC book isn't clear on it Id get a different brand.I paid for the online seloc,and was disappointed with it.

 

[markhoekstra]

Re: 1982 Merc 50HP Carb Adjustments

Sorry, I guess I didn't state that clearly. There isn't a spring on the float. The spring is attached to the needle. The needle is inserted into the carb, and the spring is what contacts the hinge-side of the float. I attached a picture - Part 14 is the needle with the spring attached, Part 8 is the float. The adjustment is to slightly bend the tab on the hinge that the pin (part 9 ) attaches to the carb.

 

[markhoekstra]

Re: 1982 Merc 50HP Carb Adjustments

The motor continues to run fine, so I guess I'll assume that I'm OK to go. If anyone else can think of any problems here, I'm still interested to know.

Thanks!