Enrichener Question

[Cordovakid]

I am somewhat confused as to exactly how an "enrichener" (not a true choke) works on a 2-stroke Merc. Specifically, I have an early 80's 25hp Merc that has the plunger-type button which is engaged when the "choke" knob is turned / pulled. My question is, when this plunger is depressed, does it squirt a small amount of fuel / mist into the carb throat each time the knob is turned / pulled, or, does it simply allow fuel to flow into the carb throat when the knob is engaged in the "choke" position, and will continue to do so until the bowl is empty? Just want to make sure I'm not flooding my engine during cold starts, etc.

Specifically, the engine is a 1980 25hp Merc, Tillotson carb. Any insight would be greatly appreciated.

 

[Chris1956]

Re: Enrichener Question

A typical enrichener on an OB allows raw fuel to enter the carb throat or intake manifold. Of course some British BSA/Triumph motorcycles has "ticklers" that used a pushbutton plunger to sink the float, flooding the carb.

It is hard to see what your carb has, but since no one else has answered, I thought I would attempt. Maybe you have some sort of tickler?

 

[wired247]

Re: Enrichener Question

It opens up a solenoid that allows raw fuel to squirt into the intake manifold. at the base of the carb. Hokey system but it works.

 

[MH Hawker]

Re: Enrichener Question

Their are two types, a manual and electric, the manual is the type your asking about, when you pull out the knob it pushes down on a plunger in one side of the carb and it dose squirt a bit of fuel in, the electric has a rubber tipped plunger on a solenoid that covers a hole in the side of the carb body that pulls in extra fuel when the motor is cranked

 

[Cordovakid]

Re: Enrichener Question

Thanks everyone for the help. It is definitely a manual enrichener. When I turn the knob all the way clockwise, it actuates a lever which pushes a rubber piece down onto the plunger. If I want the plunger to release from the down or "activated" position, I have to turn the knob back counterclockwise to pull the lever back up. When I had the carb apart last spring for a full rebuild, I noticed that the enrichener consists of a small metal plunger located within a spring inside a port at the top right of the carb. I suppose when I bring the motor out this spring, I could remove the carb from the intake, prime it with fuel to fill the bowl, and then push down the plunger to see if it squirts out a single shot, or just keeps emptying the carb for a period of time until the pressure in the carb has been released.

Any other thoughts as to this vintage of carb? This motor typically gives me trouble cold starting. Hard to tell if I'm flooding it or not giving it enough fuel to the intake - hence, the question about how the enrichener works.

 

[Mi duckdown]

Re: Enrichener Question

Staring procedure IS to pull choke knob in and out 1 to three times turn knob cw,once started and warm, knob, ccw. has worked for from 100 degrees to 0 degrees F. A well tuned motor will start. IF the enricher is BAD. then None of the above means anything. need to pull the hood and see if things are working properly.???

 

[oldman570]

Re: Enrichener Question

All the early 25hp Mercs I have worked on, and own, do not have that carb on them. That carb is of a later 1980's early 90 vintage. There is a chance that a PO has changed the carb or the motor has been changed to a newer power head. What is the SR# of the motor? All the 25's that I have worked on with that carb set up you should just have to pull the choke out and turn it CW and the motor should start and run at a high idle until the motor gets warmed up. Then just turn the knob but still leave it pulled out for a low idle with just the choke on till the motor is good an warm then you can push the choke in. Look to see if there is a SR# on the welch plug on the power head and if it matches the one on the transom bracket. If the do not match then you could have a newer power head. JMO
Oldman570

 

[Cordovakid]

Re: Enrichener Question

I agree that this is an unusual type of carb, but I am posititve it is the original model (or if not the original carb, then it is a NOS replacement of the correct part).

I don't believe this Tillotson operates that much differently than the later Walboro carbs which replaced the Tillotson from 1983 onwards into the Merc 18 / 25XD models. I also had a 1992 9.9 merc which had a Walboro carb with the exact description of the enricher / idle mechanism that oldman570 described. That motor had a "primer" which I knew squirted a small amount of fuel into the intake. But this enrichener is different, I believe. I put new plugs in last year, correctly adjusted the carb low speed idle in the water in gear. Will double check for blue spark in a couple of months when I get her out of my shed.

I have a copy of the correct OEM service manual, but not the owner's operation and maintenance manual. The service manual makes reference to the owner's manual for correct starting procedure for this type of carb (ugghh!!). Again, it's a 1980 / 1981 Merc 25hp. I believe they only put this type of carb in for 1980, 81, 82 and parts of 83.

 

[oldman570]

Re: Enrichener Question

Here is a link for manuals for Merc motors and you can find the starting procedure at page 101 or close.
Boatinfo - Mercury Service Manual for 20jet-20-25hp
You should find most all info that will cover your motor. JMO
Oldman570