First of all great videos thanx. Mike I have 2 barrel carb on 4.3 mercruiser just had the engine rebuilt. Runs smoothly and ideal rpm are good. I'm getting a bit of gas in my exhaust wash . Could this be running to rich or a hung up choke?
Can the choke be removed or disconnected and the linkages work the same on the Carb without effecting engine performance at (operating temperature)? It should just effect cold starting right?
Hi there, cold start idle is fine on my carb. But after a long run, coming back in to dock idling i stall out. Is this a carb adjustment or something else ?
Hi Mike. Thanks for the video. I just had my carb rebuilt. Now it starts fine when cold but after warmed up, it has trouble starting after setting for 10 or 15 mins. I would appreciate any input. Thanks.
What exact Carb is that? I’ve ordered two gasket kits now, with no luck getting the gaskets I need. Mine says Rochester 2 Jet on top, and that’s what I based my orders off of. Thanks. Jason Abernathy
The instructions for my carb kit mention setting the choke unload by bending the tang on the throttle linkage. I don't see the tang anywhere on it. Do some carbs not have that piece? I see where it should be on your carb in the video, but I don't even see where mine would have broken off. My carb is 807504.
Is there any choke adjustment to make with the TKS choke/system? I know it’s ‘supposed’ to do it all automatically but wondering if it can go out of wack? 🇨🇦
Hi, do you sell the choke thermostat element for this carb on your website? Mine is worn out and will not push the cam closed. I have tried adjusting it. Is there an automobile equivelant? Thanks,
Excellent video. Thank you. What is the screw at the left of the picture at minute 3.05? The gold screw with the spring that is at the bottom of the carb. Does it do anything important? I appreciate your input.
The Brass screw at the base of the carb is an air intake idle set. I Believe., I turn it clockwise until it lightly seats then back it out 1-1/2 to 2 turns and seems to be in the ball park..
Hello Mike, I'm replacing a 4bbl Quadrajunk carb with a thermal choke on a Merc 260. The replacement is a Mallory with electric choke. My question is, how does the choke work? Is the 12v to the choke constant and the carb will adjust itself, or is there a voltage adjustment somehow done electronically? Thanks
Mike, was the fast idle cam ever made from brass? My son-in-law has a Mercruiser 3.0 from the late '80s with a Mercarb, and the fast idle cam appears to be made of brass. The cam has no effect on the idle speed when I move it through its range of movement, leading me to think the brass has worn down and is no longer a cam. I've ascertained that the idle speed screw is definitely in contact with the came. Am I missing something? Thanks
Thanks, I'll take another look, but it's definitely not moving the throttle at all. I should look for a replacement cam. Are you a good source for those things?
In some markets (i'm in portugal--to the left of spain (it's in europe!)) the idle "cam" IS NOT a cam,it's round,NO change to the throttle plates; i was cleaning two mercarbs (off of 3.0 -181- L4 Mercs) and they BOTH have ROUND-no cam- idle screw stops! That is because of the old merc. shitty shifter and it's dog clutch,you cannot have a high idle,and since it usually stays around 20ºC and up here,you almost need no choke,just pump the shifter 3 or 4 times and crank away...
THERE IS NO CAM!! Here goes: My Marine MERCARB DOES NOT HAVE A FAST IDLE CAM; if i look closely(i don't mean with my eyes closed) i see that the cam is ROUND!!! and i see that the 2 butterflies stay put as the "CAM"--not a cam,remember?-- is turned; Now,why is that? it's because of the clutch dog/dog clutch on the bottom of the stern drive(no kidding,I worked for Merc).
Jose is absolutely correct. A marine carburetor will not have what is normally referred to as a "fast idle cam" in the automotive world. The cam on a marine carb maintains the same radius thru its range of motion, and therefore has no effect on RPM. Raising the idle speed is left to the vessel operator, thru the use of throttle lever(s) while disengaged from the Forward/Reverse action. Shifting in and out of gear must be done at the lowest possible RPM to preserve the transmission/outdrive.
THe "Fast Idle Cam" does NOT increase idle speed on marine carbs because the linkage rigidly holds the throttle in position based on the control lever. A fast idle cam, like in an automobile, would attempt to fight the contol cable position and put things in a bind. Also, it is bad for the gearbox to shift at higher than idle speed. So you are supposed to run the cold engine at higher speed manually from the control until it is warm enough to idle at the normal speed before shifting. The cam might be there only to provide friction so the choke doesn't flutter around.
Thanks for the info buddy! You might be just the guy to answer a question I have on my Mercruiser 3.0 if you don’t mind sharing a little more knowledge please? The moment the idle screw touches the cam (which I can see is round as you mention) it binds up and the choke won’t move anymore. Adjusting the screw until it even slightly touches the cam causes this, and the spring in the choke doesn’t have enough strength to overcome it. Is that correct?? Or is the throttle cable out of adjustment maybe? It’ll run perfectly at higher rpms but cold or warm it won’t idle 🙄 Thanks very much!
Gotta be best video out there, he teaches choke adjustment and everything else you should know to get her purring
Thank you
We appreciate the feedback. Thanks
Great job on the mercarb videos Mike, very helpful!
Thanks bro....just lined mine up and now engine humming smooth.....
Thanks for posting video so quickly, I am sure it will me out
Just the video I was looking for thanks a bunch
@@MikesCarburetor can you tell me where to get a rebuild kit for the mercarb?
Is the idea then to hold the choke open to set the idle cam when the engine is cold so that you're setting idle as if the engine were warmed up?
First of all great videos thanx. Mike I have 2 barrel carb on 4.3 mercruiser just had the engine rebuilt. Runs smoothly and ideal rpm are good. I'm getting a bit of gas in my exhaust wash . Could this be running to rich or a hung up choke?
Can the choke be removed or disconnected and the linkages work the same on the Carb without effecting engine performance at (operating temperature)? It should just effect cold starting right?
what is the recommended setting for the air/fuel screw crew? thanks!
Hi there, cold start idle is fine on my carb. But after a long run, coming back in to dock idling i stall out. Is this a carb adjustment or something else ?
Hi Mike. Thanks for the video. I just had my carb rebuilt. Now it starts fine when cold but after warmed up, it has trouble starting after setting for 10 or 15 mins. I would appreciate any input. Thanks.
HI JUSTIN. IM HAVING THE SAME ISSUE W/ MY BOAT. DID YOU HAPPEN TO FIGURE OUT THE ISSUE WITH YOURS?
What exact Carb is that? I’ve ordered two gasket kits now, with no luck getting the gaskets I need. Mine says Rochester 2 Jet on top, and that’s what I based my orders off of.
Thanks. Jason Abernathy
The instructions for my carb kit mention setting the choke unload by bending the tang on the throttle linkage. I don't see the tang anywhere on it. Do some carbs not have that piece? I see where it should be on your carb in the video, but I don't even see where mine would have broken off. My carb is 807504.
Is there any choke adjustment to make with the TKS choke/system? I know it’s ‘supposed’ to do it all automatically but wondering if it can go out of wack? 🇨🇦
So what would cause the throttle not to idle down after throttling?
Hi, do you sell the choke thermostat element for this carb on your website? Mine is worn out and will not push the cam closed. I have tried adjusting it. Is there an automobile equivelant?
Thanks,
Excellent video. Thank you. What is the screw at the left of the picture at minute 3.05? The gold screw with the spring that is at the bottom of the carb. Does it do anything important? I appreciate your input.
The Brass screw at the base of the carb is an air intake idle set. I Believe., I turn it clockwise until it lightly seats then back it out 1-1/2 to 2 turns and seems to be in the ball park..
idle mixture screw and its best to use a vacuum gauge to set it correctly
Hello Mike, I'm replacing a 4bbl Quadrajunk carb with a thermal choke on a Merc 260. The replacement is a Mallory with electric choke. My question is, how does the choke work? Is the 12v to the choke constant and the carb will adjust itself, or is there a voltage adjustment somehow done electronically? Thanks
Thank you sir.
Mike, was the fast idle cam ever made from brass? My son-in-law has a Mercruiser 3.0 from the late '80s with a Mercarb, and the fast idle cam appears to be made of brass. The cam has no effect on the idle speed when I move it through its range of movement, leading me to think the brass has worn down and is no longer a cam. I've ascertained that the idle speed screw is definitely in contact with the came.
Am I missing something?
Thanks
Thanks, I'll take another look, but it's definitely not moving the throttle at all. I should look for a replacement cam. Are you a good source for those things?
In some markets (i'm in portugal--to the left of spain (it's in europe!)) the idle "cam" IS NOT a cam,it's round,NO change to the throttle plates; i was cleaning two mercarbs (off of 3.0 -181- L4 Mercs) and they BOTH have ROUND-no cam- idle screw stops!
That is because of the old merc. shitty shifter and it's dog clutch,you cannot have a high idle,and since it usually stays around 20ºC and up here,you almost need no choke,just pump the shifter 3 or 4 times and crank away...
Then watch the video for setting the chock pull down.
the carburetor has a filter???
can u repeat what u said again?🤔
😂
THERE IS NO CAM!!
Here goes:
My Marine MERCARB DOES NOT HAVE A FAST IDLE CAM; if i look closely(i don't mean with my eyes closed) i see that the cam is ROUND!!! and i see that the 2 butterflies stay put as the "CAM"--not a cam,remember?-- is turned;
Now,why is that? it's because of the clutch dog/dog clutch on the bottom of the stern drive(no kidding,I worked for Merc).
Jose is absolutely correct. A marine carburetor will not have what is normally referred to as a "fast idle cam" in the automotive world. The cam on a marine carb maintains the same radius thru its range of motion, and therefore has no effect on RPM. Raising the idle speed is left to the vessel operator, thru the use of throttle lever(s) while disengaged from the Forward/Reverse action. Shifting in and out of gear must be done at the lowest possible RPM to preserve the transmission/outdrive.
THe "Fast Idle Cam" does NOT increase idle speed on marine carbs because the linkage rigidly holds the throttle in position based on the control lever. A fast idle cam, like in an automobile, would attempt to fight the contol cable position and put things in a bind. Also, it is bad for the gearbox to shift at higher than idle speed. So you are supposed to run the cold engine at higher speed manually from the control until it is warm enough to idle at the normal speed before shifting. The cam might be there only to provide friction so the choke doesn't flutter around.
Thanks for the info buddy! You might be just the guy to answer a question I have on my Mercruiser 3.0 if you don’t mind sharing a little more knowledge please? The moment the idle screw touches the cam (which I can see is round as you mention) it binds up and the choke won’t move anymore. Adjusting the screw until it even slightly touches the cam causes this, and the spring in the choke doesn’t have enough strength to overcome it. Is that correct?? Or is the throttle cable out of adjustment maybe? It’ll run perfectly at higher rpms but cold or warm it won’t idle 🙄
Thanks very much!
there is no fast idle on marine carbs thats not a ca
m