Carb in Bits - Help please - 50 HP Merc

[Biggles]

Hi all I wonder if anyone can help me with this:-<br />Mercury Bluband 50 HP 2 Stroke 4 Cylinder 2 carb.<br />I am in the middle of servicing the carbs, this is the first time I have carried this out on any engine. I am following the Clymer Mercury Outboard Shop Manual 45 - 25 HP 1972 - 1989 (B726).<br />The carbs appear to be those shown on page 134 and 135 which are the Integrel Fuel Pump Carburetor (Except 45 and 50 (4-Cyl) HP Models). Actually marked on the carbs is WMA 3-3 for the bottom carb and WMA 3 - 1 for the top carb. Both carbs also have the date 8/84 stamped on them.<br />I have two questions the first being:-<br />I am following the manual and have managed to get everything completed up to part 6 stage B (Fig 13). At this stage I have located and removed the idle restrictor tube plug screw (A. figure13) and now need to unscrew the idle restrictor tube from inside the main discharge nozzle. I presume this is inside where the screw (Part A) comes from. I can't work out how to get it out. I can see a very small brass coloured tube inside but it has no marks or cuts in it to allow you to unscrew it with a screwdriver. Has any one worked on this carb and if so am I missing something. Or is it that I have a carb wher the tube doesn't come out.<br />Once I have got the tube out then the next part is to remove the fixed high speed jet. I don't want to do this in case the tube is fitted in to it and I damage it. Obviuosly I would like to follow the manual so i can clean the carb properly.<br />Any help would be appreciated before March so i can get the engine back together and on the sea.<br />Regards Biggles...

 

[dolluper]

Re: Carb in Bits - Help please - 50 HP Merc

On the top of your carb part of the throttle shaft linkage is the screw your looking for

 

[Laddies]

Re: Carb in Bits - Help please - 50 HP Merc

The joys of a Clymers manual, the idle tube is pressed in leave it in, clean it with spray carb. cleaner and just go ahead and unscrew the high speed jet

 

[Biggles]

Re: Carb in Bits - Help please - 50 HP Merc

laddiesservice <br /><br />Thanks for the reply that is justwhat I wanted to hear.<br /><br />This site is excellent.<br /><br />Regards Biggles

 

[rodbolt]

Re: Carb in Bits - Help please - 50 HP Merc

biggles<br /> what is the engine ser #?

 

[dodl]

Re: Carb in Bits - Help please - 50 HP Merc

Hello rodbolt,<br /><br />I am afraid, biggles does not have the serial <br />The carbs are the Type B, according to the Seloc Manual. The ones with the integrated fuel pump.<br /><br />I had mine disassembled this summer, and the tube came out when i was cleaning with Naphta and compressed air. There was also a gasket at the bottom, so i think the tube should come out to replace that gasket?<br /><br />cu<br />martin

 

[dolluper]

Re: Carb in Bits - Help please - 50 HP Merc

it does come out and there is a gasket [o-ring]it is on the top and it's a screw type plug beside the throttle shaft as stated in my other post it's screwed out of the top of your carb!

 

[Biggles]

Re: Carb in Bits - Help please - 50 HP Merc

dolluper<br /><br />I can get the screw off the top that is part "A" according to the manual, but it isn't attached to the tube and there is no obvious way of getting it out.<br />I think its a combination of two of the answers to get it out. It looks pressed in and it sounds like when dodl cleaned the carbs with the carb cleaner that destroyed the gasket and allowed the tube to fall out. Then it could be pushed back in with a new gasket.<br />I hope it goes like that anyway.<br /><br />The main thing I am worried about if I go down this route is that the tube interlocks with the high speed jet and the high speed jet gets damaged taking it out a step too early.<br /><br />Regards all Biggles.<br /><br />I shall be having a go tomorrow dinner time GMT so i shall let you all know after that.

 

[dolluper]

Re: Carb in Bits - Help please - 50 HP Merc

it just unscrews maybe you have varish or goonck holding ,the oring may have swelled also making it tough to move,assuming you already have the idle mixture screw out,swipe the old ladies tweeser's,besides you should have the high speed jet out BEFORE you take the idle tube out,his probably fell out with the air pressure[not scewed in right] if you clean without this step you will damage the oring[gasket] and you will have to do it all over again ,anyways it's good practice

 

[Biggles]

Re: Carb in Bits - Help please - 50 HP Merc

tried the tweezers no luck.<br /><br />Just going to take out the highspeed jet and see what happens.<br /><br />Will report back tomorrow.

 

[dolluper]

Re: Carb in Bits - Help please - 50 HP Merc

yes yes take the high speed jet out first as post above as a rule of thumb when dismantelling carbs you work from the bottom up,so relax have a beer and read s l o w e r exspect to hear when you link and sync

 

[Biggles]

Re: Carb in Bits - Help please - 50 HP Merc

Right I took out the High Speed Jet and basically finished dismantling everything. The idle tube is still in situ.<br />Next week I'm going to get some carb cleaner and do the cleaning.<br />Is it okay to put the whole of the cast carb in the cleaner or do you just use spray on that part.<br /><br />Regards Biggles.

 

[AMD Rules]

Re: Carb in Bits - Help please - 50 HP Merc

Soak the entire assembly in cleaner. The appropriate length of soak time will depend on the amount of varnish that may have built up over time. A toothbrush makes a good tool for scrubbing hard to reach surfaces. When you're done, spray all over with more cleaner and then with compressed air blow out all orifices and small crevices. Dry well and you should be all set to re-assemble.

 

[dolluper]

Re: Carb in Bits - Help please - 50 HP Merc

soaking in cleaner is the best parts that are metal only ,DON'T soak float gaskets or orings the idle tube may be alot easier to come out after it soaks ,can't understand why it isn't unscewing for you

 

[Biggles]

Re: Carb in Bits - Help please - 50 HP Merc

Hi dolluper,<br /><br />The idle tube looks as if its pressed in. There is certainly no way of unscrewing it. I'll keep you posted on how it goes. <br /><br />Regards Biggles

 

[dolluper]

Re: Carb in Bits - Help please - 50 HP Merc

right the soak will probably loosen it i hope someone didn't use blue locktite on it in a previous re-build

 

[Reel Precision]

Re: Carb in Bits - Help please - 50 HP Merc

be careful not soak too long. The carb has a coating on the inside to make the metal pervious (spelling??) to the gas. Soaked too long the cleaner will eat at this coating.

 

[Biggles]

Re: Carb in Bits - Help please - 50 HP Merc

Hi Reel Precision<br /><br />So whats a good time to soak the carb for. Minutes or hours ?<br /><br />Also I suppose this doesn't count for the brass bits.<br /><br />The carbs aren't really that mucky inside. I think the main problem with them has been worn Inlet Needles and spring and possibly float valve incorrect settings.

 

[Biggles]

Re: Carb in Bits - Help please - 50 HP Merc

Heres another one to add to the list.<br /><br />I just took delivery of a spare set of carbs whic I bought because they were going cheap and might be needed if I muck up my cleaning process.<br /><br />These have the idle tube attached to the grub screw. Different again but very simple to get out.<br /><br />Going to get the carb cleaner tomorrow so i shall keep you posted.

 

[Biggles]

Re: Carb in Bits - Help please - 50 HP Merc

Well I got the gaskets etc. Why do they duplicate the kits. Or not quite duplicate them. Any way it took 2 days from the US which isn't bad but I paid a fortune for the delivery. In the UK it would have been £100 for $40 worth of parts. Rip off or what.<br /><br />I've rebuilt one carb.<br /><br />I have two sets of carbs for the same engine and they both differ slightly from the manual. I guess improvements to the function of the carb account for this. But it would be nice to know which of the two carbs I have are the more modern and better.<br /><br />Also I haven't beeen able to get the idle tube out yet even though its been soaked in cleaner. <br /><br />Give it a week and I should be able to fire the engine up and give it a run.<br /><br />Will keep you posted.