Priming Problem

[dburr]

When priming should fuel reach both top and bottom carb. I can only see fuel visiably getting the bottom carb then the bulb is hard. This engine has no power so could it be running on 2 cyls (its a 4). Or would this problem fix itself when started?<br /><br />I appreciate any help I can get

 

[ob]

Re: Priming Problem

The bulb should continue to pump fuel to all carbs until their bowl floats seat,which is why the bulb gets firm.What is your issue? Is your engine hard starting?Post the model number or year and hp of your engine.

 

[dburr]

Re: Priming Problem

Its a 79 50hp, I just replaced the internal fuel line to the mechanical pump and checked the diaghram.....looks good. So once I finished this I primed the engine to check for any leaks. The person who had it before me put clear lines on the output of the pump. Its goes from the pump tot the bottom carb(which fills) and at that carb theres a T which jumpers it up to the TOP carb, I see fuel trying to get to the carb, but by the time the bulb is hard no fuel gets to it. Basically since I bought it, its not had any power ( or at least as much as it should) brought it to a shop to clean the carbs. He said he fixed the bottom carb, cleaned both and commpression check it and everything was good. I got it back from him and nothing really had changed. Please help, Im ready to drop it off the back of the boat.<br /><br />Cheers,

 

[ob]

Re: Priming Problem

Sounds like the is a problem with the carb that the fuel won't reach.Maybe a stuck needle valve or restriction ,but something is amiss.<br /><br />Are you saying that there is a clear viewing line to both carbs or just leaving the pump??

 

[dburr]

Re: Priming Problem

no to both carbs. Everthing on the output of the pump is clear. If theres air in the top carbs line should it pass out throught the carb while it fills? Or is this a air block or something. How do I check the valve Ive never been inside a carb before. Pleae help I appreciate it, as you can tell I dont want to being it to the shop again, that was $180 for nothing

 

[ob]

Re: Priming Problem

dburr,Carburetor removal and maintenace is a fairly straight forward procedure and is not very difficult.However at this point it would be highly recommended that you first obtain an engine manual that will walk you through the steps of the carb maintenance and troubleshooting procedure.Lots of good stuff in an engine specific manual.It'll pay for itself a hundred times over and if there are any fine points that need to be clarified ,one of the fine gentlemen of these forums will assist.

 

[dburr]

Re: Priming Problem

Thanks alot Ob. I will try to get a manual ASAP. I will remove the lines from the carbs tomorrow and see if it can push through both. If I can I guess its off with the top carb. Those *******s at the shop. Man you cant trust anyone these days.......Im thinking they didnt even pull the carbs off the engine now. Besides that there was a broken hose on the side of the powerhead. There is three of them, I couldn't get a striaght answer from the shop on what they were, he just said put a new one one. Bunch of idiots. I should of just asked guys like you in the first place. Thanks again.

 

[ob]

Re: Priming Problem

10/4 . Make sure and give us an update on your findings.

 

[rboat99]

Re: Priming Problem

dburr, speaking from the point of view of someone who had never worked on any carb (let alone one for a marine engine) I have to say that rebuilding the carbs is not as hard as I thought it would be. <br /><br />As long as you have a good manual to follow, the experience will clarify how that part of the engine works.<br /><br />As for the air in the carb question, the process of priming the carbs with the primer bulb should displace any air in the carbs and fill both carb bowls with fuel. Once the bowls are full, then the float valve in the carbs will close and as OB said the primer bulb will become hard.<br /><br />If the bulb is getting hard before the fuel reaches the top carb then there may be a restriction or blockage downstream (or up in this case) from the bottom carb. Either the T, the line, or the float valve.<br /><br />Basically, the same thing OB said.

 

[stairliftoheaven]

Re: Priming Problem

dburr how do you know the carb that appears to be getting no fuel already has a full float chamber? If it is full it will not demand any fuel. Try opening the drain screw on that carb, you will soon see if there is fuel in there. If its empty then you have a stuck float or needle valve and will require replacement.<br />best of luck

 

[papasage]

Re: Priming Problem

i would try bumping the top carb while pumping the bulb. that sometimes dislodge the top float . had a 40 i had to do that if it sat for a weak or so . papasage

 

[COUNTRYSEPP]

Re: Priming Problem

Where do I buy a cover & gasket for the primer/choke for a 1993 Johnson 88 O/B

 

[dburr]

Re: Priming Problem

thank alot guys, I removed the hoses leading to the carbs and they were not block at all. I pulled the carbs from the engine (man they dont make it easy to get the top one off). See, I had it at the shop a couple weeks ago and they said they cleaned the carbs, but you can visably see they only did the bottom one...the outside is much much cleaner than the other one. Anyway, I pulled the float chamber apart and blew on the valve to see if it was stuck it did release but in comparision to the other carb its seems to be stickier and doesn't seem to have the same flow. I hope its the problem. I have a friend whos familiar with cleaning carbs so hes going to walk me through it tommorow and then I going to but it back together and water test it. Hopefully I finally get some power out of it. Thanks again guys. If it doesnt work any better after this where is my next investigation?

 

[ppjmb5]

Re: Priming Problem

rebuild the fuel pump<br />thats your problem about 12 bucs for the kit

 

[dburr]

Re: Priming Problem

Its a mechanical one, I checked the diaphram and it looks good. The carbs are being cleaned right now. There was a broken hose on the side of the block. There are three hoses that jumper around the block and then one runs to the front of the engine right behind the carb. I replaced it but havent got it back in the water yet as I decided to clean the carbs because of the problem I described above. I even replace the inter fuel hose leading to the pump. What can go wrong with a mechanical pump besides the diaphram? Which appears to be in good shape, actually as if it was replaced recently.