How badly have I messed up my carb?

[MikeDobbs]

Mercruiser 3.0lx - Engine serial #: 0K277779

OK, so my engine doesn't run, and I'm working through diagnosing the problem. It's been sitting for two years with previous owner, and the carb was leaking gas from float bowl side when trying to start engine so I figured a rebuild would be in order.

Everything was going fine until I got the the jets/brass looking cylinder things. They have a slot in the top so you can remove them with a large slotted screwdriver, and the video I was watching said they usually just come right out, but that was not the case on mine. 1 came right out, no problem. The other three are still in there, and the metal chipped of the top leaving me with no more slot to grab with the screwdriver. I was using a very large slotted screwdriver (I actually went to the store to buy a large screwdriver before attempting the removal), but it didn't matter. They were in there so tight, one of them actually chipped part of the blade on the screwdriver.

So, here's my question. Are the slotted parts of these things non-functional? In other words, am I better off at this point just rebuilding the carb with the chipped jets in place? Or should I get aggressive and try to remove them with a screw extractor? Or is my only remaining option to order a rebuilt carb online?

Thanks in advance : )

 

[Eric 3.7LX Alpha 1]

I believe the slot on the jet is there only to remove it with a screwdriver. As long as you didn't bugger up the hole in the jet your ok.

 

[Bondo]

Ayuh,... The hole in the center is Critical, the slots not so much,.....

Might be time for another carb,...

 

[MikeDobbs]

Some folks are telling me to just clean the jets in place and finish the rebuild- while others recommend I extract the jets with a screw extractor (reverse thread type of deal), and then of course there is the option of just buying a rebuilt carb...

Worth a shot to clean and reassemble as it? Better to extract and install new jets? Or do I just bite the bullet on a remanufactured? I'll post some pics of the damage. Would love any and all opinions : )

My kit has the two large jets pictured, but not the small one...

 

[MikeDobbs]

No Title

Here's some better shots of the jets...

 

[Eric 3.7LX Alpha 1]

How was the fuel passageway to the needle and seat? They can get blocked and prevent the bowl from filling up. I'd spray it with carb cleaner and air thru each jet and if it flows out somewhere else I wouldn't mess with them.

 

[Bondo]

Ayuh,.... I hate to spend Yer money for ya, but I'd tryin' find a used or reman carb for it,.....

 

[MikeDobbs]

Bondo- I'm well prepared to order up a rebuilt one if I have too- just don't want to jump the gun. Do you think I will be unable to remove with an extractor? Or are you saying the small one is too badly damaged already to function properly?

I figure I should reassemble the carb (either replacing the jets after extraction, or cleaning existing ones in place) and give it a shot before buying a reman carb... but are you saying you think there's too much damage to be worth trying?

Thanks

 

[Bondo]

Ayuh,.... If you use a screw extractor in the center hole, that jet is junk, 'n you'll need new jets,.....

The 1st 2 look beat up very near the orifice,.... The long one, might clean up,....

 

[johnkom]

The long one is the needle valve seat for the needle valve--technically not a "jet." Get or borrow an "impacter" not a drill and the right size screw driver bit. Hold it firm and let the impactor do its magic. Don't let it slip. Sometimes the vibration of an impacter will back a screw/bolt out. If you shred the brass replace the carb.

 

[gm280]

Personally as OCD as I am, all of them would be removed. And then the body cleaned and inspected and if the body looked good, contact the manufacture and buy new ones for replacements. I've actually done that before and it worked out perfect. Obviously there is already corrosion there or the jets and seat would come out easily. So corrosion spells trouble and needs to be cleaned and examined. All passages need to be clean and free of such corrosion completely, if you want the carb to run properly again. JMHO!

 

[johnzonh]

Soak with some pb blaster. Might make it a bit less traumatic in the Jets

 

[johnzonh]

I used a lot of downward pressure to get mine out on a Mercarb 2bbl but not before soaking them all with pb. Mine was caked in salt water rust and ethanol goobers. Any penetrating fluid helps.

 

[gm280]

Mike, let me explain my reasoning for taking them all out, because I'm sure a lot of folks disagree with me on this subject. I had a Kohler 15 HP lawn mower that I use to mower my yard. Well back a few years ago it stopped cranking and I noticed all the gas was gone form the tank. It is a gravity flow setup so there is no fuel pump. So I checked and all the gas was now in the crankcase with the oil. Certainly not good. So after draining the oil and putting fresh oil and new filter on, I fueled up the tank again and mowed. The next week the exact same issue. The gas was again in the crankcase mixed with the oil. So I bought a carb kit and rebuilt the carb. All new parts installed and it looked new. The very next week the exact same thing again. I was getting very frustrated because even after rebuilding the carb I tested it with blowing into the fuel inlet to make sure the float was work and it was. So again new oil, filter and refilled the tank again. Ran perfectly. The next week again the gas in the crankcase. Now I was getting really upset. How can that be. So I bought and installed another carb kit. And again it tested perfectly. But each carb kit came with a new needle and of course gaskets. And I took ever measurement to verify the float and all were properly set. And then I filled up the tank only to see it flood up in the carb again in about a minute or two. So I knew something was wrong. Kohler never ever sent any seats for their carb kits always a new needle. And the internet was all abuzz about others having the same problems. So I had to buy a new seat as a emergency fix for their carb. And that fixed it. So even though the carb passed the blowing into it upside down and right side up to verify the needle and seat were good, they actually weren't. So now every time I rebuild any carb all jets and seat come out and are inspected for wear and tiny pits in them. So that is why I stated to remove them all and replace if they are damaged... JMHO!

 

[johnkom]

No Title

Like this?

JK

 

[MikeDobbs]

Thanks everyone for the replies- as a new boater with a used boat I am VERY appreciative of the support I'm getting on this forum!

Captain- I totally understand and agree with your point of view to remove the jets. I actually broke down this afternoon and sought professional help on this one. I was afraid I might do more damage trying to remove them, and was afraid they were already too damaged to reuse anyway.

The pro is going to get the jets out- he said that on these carbs in particualr it's critical to get all the jets and the power valve (the one near the two jets) out because they tend to collect a lot of corrosion and what not down under those parts.

He'll rebuild it for me and get it back to me on Thursday, which leaves me time to pull the outdrive and do the bellows : )

Thanks again- I'll know better what to expect with the next rebuild.

BTW- is a carb rebuild something you do as scheduled maintenance every year or two? Or just when there is an issue?

 

[Bondo]

BTW- is a carb rebuild something you do as scheduled maintenance every year or two? Or just when there is an issue?

Ayuh,.... Keep water, 'n crud outa yer carb, 'n ya may never have to ever rebuild another one,......

'course, one douse of water, 'n crud, 'n you could be doin' it again next week,....

 

[Eric 3.7LX Alpha 1]

Nothing wrong with sending it out....

Let us know how you make out after you get it back and bolted in. :thumb:

 

[philipp10]

Just leave the jets in place and spary them out. As long as the hole is not messed up you will be fine. I almost never pull jets in a carb rebuild (and I have done many) as they can just be cleaned in place. Your fine to just do that. Don't over-think this.

 

[keith2k455]

Either find a way to get it apart or buy a new one. What if you find you need to change jets after all this? You'd be back right where you are now.