My carbs differ from what is depicted in the service manual.

[clanton]

Re: My carbs differ from what is depicted in the service manual.

The screw is for the idle circuit, but may effect the intermediate circuit. If the carb has the 2 small jets on front of carb indicated in BRP parts diagram, both control air flow, 1 is for idle, 1 is for intermediate circuit.
I also think all of the circuits in the carb overlap some.
I would start with 2 turns all 4 carbs, adjust until it runs well, are you think you are loseing it.

 

[Haffiman]

Re: My carbs differ from what is depicted in the service manual.

The loopers carb system consists of 2 parts -the plastic 'carb' with main jet and air jets/corrections for idle and intermediate.
Any plastic carb with adjustment screw will adjust air, any throttle body with adjustment screw(s) will adjust fuel.
As general rules:
1:Air screws - start from 1 out and adjust out (counter clock wise)about 1/4 each time. When cylinder 'sneezes', go back 1/4-1/2 in.
2:Fuel screws - start from 3 out, go in( clock wise) 1/4 each time. When cylinder sneezes, go out 1/4-1/2.

In both cases, throttle plates must be completely closed,boat launched or engine in barrel with correct back pressure. NOT on muffs!!!!
RPM preferably below 650 rpm. The lower the rpm, the easier to adjust.

 

[seahorse5]

Re: My carbs differ from what is depicted in the service manual.

One quick way to find out if your engine has air adjustment screws or fuel adjustment screws is to see where they are mounted. Air screws are threaded into the plastic carburetor body and they all have slotted heads.

Fuel adjustment screws have very fine thread small diameter bodies that thread into the aluminum throttle body. You do have to reach through an opening in the carb body to reach the screw, but the screw is NOT part of the carburetor. The adjustment screw stays in place in the aluminum body after the plastic carb is removed. Most have a 9/64th Allen head on them or later ones used a special tamper-proof Torx head.

 

[D0T-C0M]

Re: My carbs differ from what is depicted in the service manual.

Very good information guys. I just want to say I really appreciate the replies.

The snow and ice is almost gone and when I get my boat out of storage I will start working on my engine. The list this year consist of changing my power pack (quick start doesn't work), water pump maitenance, changing out the thermostats and then complete carb overhaul and tuning.

 

[boobie]

Re: My carbs differ from what is depicted in the service manual.

If Q.S. doesn't work, it could also be the power coil on the stator which runs Q.S. Check that first before replacing the pack.

 

[D0T-C0M]

Re: My carbs differ from what is depicted in the service manual.

If Q.S. doesn't work, it could also be the power coil on the stator which runs Q.S. Check that first before replacing the pack.

Yes I already checked the stator last year, it measured close to 96 ohms. As per the manual it stated that if the stator reads 96 ohms +/- 10 ohms than its the power pack. The power pack is only $125 on ebay so I'm gonna put it in this year and keep the old one as a spare. I was putting it off last year.