6 hp evinrude carburetor problem flooding

johnevin24

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May 10, 2013
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Hi, I have a 1976 6 hp evinrude (6605a). The carburetor was flooding as soon as I pulled the motor over. I took the carb apart and cleaned it 4 times but still floods. I just rebuilt the carb with NEW CARB kit, set float etc. Now the thing will only run with the choke on. As soon as I go to take the choke off it quits running. I have also put another fuel pump on and still does the same thing. I checked all bolts etc and everything is tight. I cant figure this out,any suggestions? thank you. p.s. I also set the adjustment to 1-1/2 turns but even if I turn it in or out in small increments it still does the same thing.
 

Cap'n Chaos

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Re: 6 hp evinrude carburetor problem flooding

There is a small metal clip that connects the needle to the float, did you install that? Also, did you install the boss gasket?

When upside down the float should be about 1/16th" and level above the body of the carb.
 

johnevin24

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Re: 6 hp evinrude carburetor problem flooding

Hi capt., yes i put on the little clip. as far as the boss gasket goes i assume you mean the small round one that pushes over the jet. as i said i put a rebuild kit on the carb. also the main problem now isthat it will only run if the choke is on. thanks again.
 

nwcove

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Re: 6 hp evinrude carburetor problem flooding

did you use an omc kit ....or an aftermarket? did you need to use the bowl screws to compress the boss gasket, or did the bowl sit easily against the carb body?
 

johnevin24

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Re: 6 hp evinrude carburetor problem flooding

Hi, I assume the kit was an aftermarket kit. As far as the fuel bowl goes it sat right on top of the new bowl gasket flush and i just tightened up the screws. Idont think the boss gasket comes even close to the bottom of the bowl to even touch it. I kept going from screw to screw until they were all tight. WHAT WOULD THIS HAVE TO DO WITH IT ONLY WILL RUN WITH THE CHOKE ON. thanks.
 

AlTn

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Re: 6 hp evinrude carburetor problem flooding

if the question is why it will only run with the choke on, the answer is simple: that's the only way it's achieving a fuel/air mix capable of sustaining combustion.

if the question is why the boss, or nozzle, gasket seal is necessary, that's simple as well: w/o it the pressure differential between the atmospheric pressure within the carb and the reduced pressure within the venturi, or the carb throat, isn't great enough to force fuel into the nozzle from the orfice plug. The nozzle needs to be sealed so that it's only supplied by fuel from the orfice jet.

if the question is what can I do to get my engine to run properly w/o the choke having to be in use: post back for further suggestions.
 

nwcove

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Re: 6 hp evinrude carburetor problem flooding

Is anyone going to answer my question?

a failure in the quick response dept is usually caused by an over due iboats acct!!......oh wait......this is a free site. :facepalm:

ok, on to the boss gasket. ive had a few aftermarket kits that the boss gasket was to thin and would not seal. it results in a hard starting or no start situation. ie the venturi effect in ineffective. if that is the case with your motor ( still could be that your carb wasnt cleaned and rekitted properly), my usual quick and dirty fix would be to use one or two of the extra fiber washers under the gasket to make up the needed thickness.
 

ddwilson

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Re: 6 hp evinrude carburetor problem flooding

if it will not run with the choke off, check the idle jet screw and make sure it is adjusted properly, to start with would try @ 1- 1 1/2 turns
out from seated, to start with and adjust from there when running. It could also be a piece of crud blocking a jet in the carb.
Doug
 

Tim Frank

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Re: 6 hp evinrude carburetor problem flooding

When you "rebuilt" or "cleaned" the carb, did you pop the welch plugs and check behind them?
 

johnevin24

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Re: 6 hp evinrude carburetor problem flooding

ok,lets start over. the motor would only run if the throttle was half open or more. it would not idle and shut right off. there was lots of gas coming out of the carb as soon as you pulled the cord. I took carb apart 4 times and cleaned it. same thing was happening. i then put in a new carb kit,again cleaning with brake cleaner made sure EVERY hole etc. was clean and working. adjusted the float and started with 1-1/2 turns of the needle screw. NOW IT WILL ONLY RUN WITH THE CHOKE ON and it SHUTS RIGHT OFF when you turn the choke off. no i did not remove the welch plugs as thats normally not needed and its a pain in the dumper. i have rebuilt many carbs with great success but this one is giving me lots of problemos, thanks again.
 

nwcove

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Re: 6 hp evinrude carburetor problem flooding

ok,lets start over. the motor would only run if the throttle was half open or more. it would not idle and shut right off. there was lots of gas coming out of the carb as soon as you pulled the cord. I took carb apart 4 times and cleaned it. same thing was happening. i then put in a new carb kit,again cleaning with brake cleaner made sure EVERY hole etc. was clean and working. adjusted the float and started with 1-1/2 turns of the needle screw. NOW IT WILL ONLY RUN WITH THE CHOKE ON and it SHUTS RIGHT OFF when you turn the choke off. no i did not remove the welch plugs as thats normally not needed and its a pain in the dumper. i have rebuilt many carbs with great success but this one is giving me lots of problemos, thanks again.

How could you possibly clean the ls circuit without removing and replacing the welch plug????
 

Tim Frank

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Re: 6 hp evinrude carburetor problem flooding

I took carb apart 4 times and cleaned it. same thing was happening. i then put in a new carb kit,again cleaning with brake cleaner made sure EVERY hole etc. was clean and working. adjusted the float and started with 1-1/2 turns of the needle screw. NOW IT WILL ONLY RUN WITH THE CHOKE ON and it SHUTS RIGHT OFF when you turn the choke off.

Brake cleaner does not do a very good job on carbs ...in my experience. It is mainly a de-greaser and will struggle with varnish deposits and other dried gas residue. I use Carb cleaner.
If you did not clean the passages behind the welch plugs you have not cleaned the carb. The risk is that you will dislodge substantial crud during the cleaning process and some may findits way in to those small passages....usually the slow speed circuit.

no i did not remove the welch plugs as that's normally not needed
Not sure where you heard that, but I'd be careful of any other advice you got from that source.
There is a reason that they include those plugs in carb kits.
and its a pain in the dumper.

As much as R&Ring the carb 4 times....and you are going to have to do it again, anyway, to do it properly.

i have rebuilt many carbs with great success but this one is giving me lots of problem, thanks again.

You might consider investing in the OEM manual for that motor. I got one on eBay for LT $25- in the door. It has saved me 10x that just from tests that it details that allow me to avoid just throwing parts at it.
I'll bet that fuel pump was more than $25- on its own.
 

AlTn

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Re: 6 hp evinrude carburetor problem flooding

remove and clean the orfice plug, remove the idle mixture needle, keeper and the needle valve bearing.Examine the needle valve for a bent point, grooves, etc. ,replace if necessary. Core plug removed. Clean thoroughly any passage from the bowl going up to the idle circuits. That would be any passage that isn't threaded for a float bowl screw. I've used twist ties to do this, but you have to be aware that if it breaks off in the passage it's gonna present a real problem getting it back out. Proceed at your own risk. Set the float parallel with the carb casting. Needle bearing, needle, and keeper back in place set 1 1/2 turns out. Link and sync good. If the carb is right, you should be able to produce a noticeable affect at idle by adjusting the mixture with the needle. Hopefully your carb is good to go now.
 

geoffwga1

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Re: 6 hp evinrude carburetor problem flooding

+1 And pay a great deal of attention to the packing on the slow speed needle.
Geoffwga1
 

johnevin24

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Re: 6 hp evinrude carburetor problem flooding

Thank you al for taking the time to respond. today i took the carb off again then pulled the welch plug. INSIDE WAS CLEAN as can be.Iput n new plug. I then pulled carb apart againand cleaned everything once again and as suggested but did it twice before put a thin wire in tat tiny hole and also shot cleaner through it and all passages flow as they should. i checked to make sure the float was correct etc. i also made sure the bowl was touching the new o gasket before tightening the screws. I put it back on and it fired up with one pull. choke on. i let it idle for a minute and then a soon s i take the choke off it quits. it actually runs well with choke on (not as it should of course) and now im seeing fuel coming out of the carb when i start it. also put all new fuel lines on the motor as well. im getting ready to take a sledge to the carb. the carb looks in great shape so still cant figure this out. thanks again everyone its well apreciated.
 

johnevin24

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Re: 6 hp evinrude carburetor problem flooding

also let me ad that turning the adjustment needle does not change anything. you can screw it all the way in or turn it out in increments and it makes no difference at all.
 

Crosbyman

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Re: 6 hp evinrude carburetor problem flooding

beginning to sound like your pistons, on the compression stroke, are NOT sucking in a sufficient volume of air from the carb to simoultaneously pull (suck in) the gas from either the low speed or the high speed circuits.

Could you have air leaking into the engine block from somewhere ? (bad seals??)

btw ...tank vent is openned right ?
 

Tim Frank

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Re: 6 hp evinrude carburetor problem flooding

If you have a compression tester, you can verify the compression values.

I'd still say that you have missed something in the carb.

When you removed the orifice plug, did you make sure it was full diameter....no buildup of varnish?
The ID should be .044"....a #58 drill is .042.
 

nwcove

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Re: 6 hp evinrude carburetor problem flooding

i dont think the motor would start first pull if the compression was down, im with Tim, the carb rebuild is still suspect, or its sucking alot of air from somewhere else.....maybe around the throttle plate shaft, reed plate gasket??
 
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