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Jason, Marine Mechanic
Category: Boat
Satisfied Customers: 16209
Experience:  Degree in Marine Technology. Gas and diesel marine mechanic.
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Can you explain me about Mercury 5hp 4str carb. I'm trying

Customer Question

Hello Jason. Can you explain me about Mercury 5hp 4str carb. I'm trying to adjust mixture but I see some kind of weird pilot screw. Can you confirm that this one is right one to adjust mixture? And what kind of tool should I use. Also I see on top of carb 2 outlets(looks like vacuum ones) can you tell me should they be open or it must be hoses?
Submitted: 1 year ago.
Category: Boat
Expert:  Jason replied 1 year ago.

Hello, Jason here, whom am I speaking with?

Can I get the serial number on the engine please.

Customer: replied 1 year ago.
Sorry, I thought it will add it automatically. My name is Andrii.
Expert:  Jason replied 1 year ago.

Hi Andrii,

I'm sending a picture back to you. That brass part is what is called a tamper proof cap. What you want to do is remove the carb, bring it to a work bench. Very carefully and very slowly drill a small hole in the center of that cap. After that, screw in a course drywall type screw. Grab the end of the screw with a pair of vice grips, and pull the tamper proof cap off. Under the cap is the idle mixture screw. On a side note, if you tried to clean the carb you will have to do so again, as you will have to clean out the idle passageway that is behind the screw.

The outlet on the top of the carb is just a vent, that can stay open.

I think that should do it. But I work for tips so I do want to make sure you are happy with my service before you go. If you had a further question on the issue by all means feel free to ask. If not, Just in case you do not understand the way the website works (and some folks do not). You do have to put forth a positive rating in order for it to credit me for helping you. When ratings are not done, the website simply keeps your deposit and they will not credit me. The ratings box is located at the top of the screen. To rate, you must select the star you wish and also confirm it. Please let me know if you run into any problems or errors when trying to do it. If you do have a problem, or if you can not see the ratings box which is at the top of the screen. Please reply back "I rate Jason's service _______" and fill in the blank.

Questions do not close out, so if you have to come back later on with follow up questions to the issue you still can even after doing a rating.

Thank you

Customer: replied 1 year ago.
thank you Jason, i'll text to you you update
Expert:  Jason replied 1 year ago.

You are very welcome and I was glad I could help. Please keep in mind the website has already charged you to speak with me, but they will not credit me for helping you unless you put through a good rating for me. The ratings box is at the top of the screen (you might have to scroll up to see it). Please let me know if you have any problems with it.

Thanks again,

Customer: replied 1 year ago.
Got it, trying to pull out this cap, still no success. Drilled small hole, trying to pull with screw. Can be a thread there?
Expert:  Jason replied 1 year ago.

Its not supposed to be. Its supposed to be a simple tamper proof cap. When you drilled into it. Could you feel the bit pop through and enter a small void?

Customer: replied 1 year ago.
it's was shaking and even rotated
Expert:  Jason replied 1 year ago.

ALL you have to do is yank it out with either a hook tool, or how I do it is thread in a drywall screw and then grab that with a pair of pliers and pull.

Customer: replied 1 year ago.
Ok Jason, I tried to pull but nothing happened. Than I tried to unscrew it and got it out. It was exactly pilot screw. Now after all it's messed. I'll rebuild top of the screw but still it's sad.