Mercury Carb need to be replaced?

[BigMouthBass]

Hi All,

I am new here...though I read posts on here all the time...new to posting. Also not a genius when it comes to mechanic work but I tend to figure things out. But forgive my ignorance when I try to explain this one!

I just picked up a 1997 Mercury 25 ELH Serial 0G489945. It fired right up hooked to the hose but when we took it out on the water it idled ok but killed with the slightest throttle. I assumed it was a carb issue...

Anyhow, I pulled the carb and cleaned and reinstalled (not my first carb job either). This time it would idle fine and even go into lowest speed but then killed upon further throttle. I figured it must be the float. Pulled again, checked and double checked float to factory 1". Replaced. Now it is still about the same...but actually backfires and kills when I try to throttle it.

Timing issue? New plugs, new gas, new fuel lines and hose.

Here is the kicker - I noticed when cleaning the carb that the needle (?) that goes through the carb behind the throttle plate was really gummed up. It is clean as a whistile now but I noticed the needle looks bent. I didn't want to screw with it so I left as is. I don't believe it is serviceable and if that is bad I would need a whole new carb. Should that needle be centered in the hole (wow I sound like an idiot so ask me for clarification or I can go post a pic). If you are familiar with this carb I think it is WMC 53A or WMC 25 (also something I need to figure out if you can help in case I need a new one). Anyway, that needle goes right through the intake behind the throttle plate and in to the float bowl, actually centered in the housing that the float sits around. It is angled off to one side. How in the hell that would get bent is beyond me...

Anyway, thanks for the help in advance!

 

[ondarvr]

Re: Mercury Carb need to be replaced?

They frequently aren't straight, its part of the low speed portion of the jetting.

If it ran better after you cleaned the carb then you are probably on the right track, still sounds like the high speed jet is plugged though.

 

[BigMouthBass]

Re: Mercury Carb need to be replaced?

They frequently aren't straight, its part of the low speed portion of the jetting.

If it ran better after you cleaned the carb then you are probably on the right track, still sounds like the high speed jet is plugged though.

Ok. I will stick with it one more time and see what I can do. Thanks for the input.

Maybe I will need to post another thread for this, but when I pulled the plugs to replace them, it stipped the head. Now when I put the new one in it seems to fit tight, but I am thinking it probably won't be quite right even though the plug is snug. I have heard you can use Time-Sert and not have to pull the head to re-thread. Anyone done this before? I guess I should search the forum...and will. But what are your thoughts? If it is snug should I/is it necessary to re-thread it?

 

[ondarvr]

Re: Mercury Carb need to be replaced?

Ok. I will stick with it one more time and see what I can do. Thanks for the input.

Maybe I will need to post another thread for this, but when I pulled the plugs to replace them, it stipped the head. Now when I put the new one in it seems to fit tight, but I am thinking it probably won't be quite right even though the plug is snug. I have heard you can use Time-Sert and not have to pull the head to re-thread. Anyone done this before? I guess I should search the forum...and will. But what are your thoughts? If it is snug should I/is it necessary to re-thread it?

I did this (time cert) on my F150 a couple of years ago and it has been trouble free since then, so it works.

 

[TreyThomas]

I was having the same issue with my motor. Have cleaned the carbeurator and blasted air through every valve on the thing. I’m getting gas into the bulb, but the engine won’t stay running unless I spray gas directly into the carbeurator. I was wondering if you’re problem was ever resolved and what you did to fix it.

 

[GA_Boater]

I was having the same issue with my motor. Have cleaned the carbeurator and blasted air through every valve on the thing. I’m getting gas into the bulb, but the engine won’t stay running unless I spray gas directly into the carbeurator. I was wondering if you’re problem was ever resolved and what you did to fix it.

The OP left 5 years ago. Start a new thread.

Closed.