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Reed Valves? Im lost....

N

nmTampafl77

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I have a 73 Johnson 65 and just rebuilt the carb's. I adjusted the float the way the specs indicated and the needle valve is seated properly, but when im out in the water it starts up and idles fine until I put it into gear. When I put it into gear I have to give it WOT in order to keep it running but in WOT it doesn't have enough power to make it past plane, and when I bring the throttle back it instantly dies out, but starts back up only after choking it. When I have it at the house on muffs it runs perfect. But every time I turn the motor off gas comes out of the front of the carb's. I have taken the carb's off 4 times because I thought the float was adjusted wrong and I have measured all three carb floats they are parallel with the carb body, and when I turn them the other way..... all 3 carb floats hang down exactly 3/4 of an inch. I am just completely lost and frustrated. And need help. Thanks!
 
The synch is fine i checked that.... and yes the float is level with the float bowl surface..... it only leaks gas after i turn the motor off. when it running it does not leak fuel out of the carb's at all. Only when i choke that carb's and when i turn it off after running the motor. Everything on the carb's were put back together correctly only thing i can think of is the reed valves. But how do i check to see if the reed valves are bad?
 
Well,it sounds like a float adjustment problem.I know all floats should be adjusted the same.I know what you saying.I rebuilt 4 carbs on a 1100 yamaha bike.In the manual it states what the floats should be adjusted ate.So,I adjusted the way the manual said to do.Found I wasn't getting enough fuel.Had to choke it for it to run.
Here,
If you have to run the choke to start it or for it to run.Means the floats are to low.Not enough fuel.
If the floats are to high will cause,the carbs to overflow fuel.
If you choke the carbs As full choke.The engine should die.If not the floats are not set right.
That manual your looking at tells you the adjustments for the carbs from factory 1973.Well it's 2012 now.That carb I'm sure has ware by now.That carb is old,used since 1973.Over 30 yrs old it is.You can't go by factory settings after 30 plus yrs of ware & tare.You say you done took the carbs apart many,many times already.Well,you have to do it again until you get it right.I know all about it.
Your carbs don't need to be synced unless you removed the butterflies.Your'll know if your carbs aren't synced correctly.Will pop & crack darn near catch on fire if your not carefull.It will sound like it's out of time.
You need to find out if you need more fuel or less fuel?Set them by ear so to speak.

You say?>When I put it into gear I have to give it WOT in order to keep it running.& but starts back up only after choking it.& gas comes out of the front of the carb's.
You have more things wrong then what your saying I think?
Because,When you have to WOT to keep it running mean's your not getting enough fuel.Since you have to choke to start it mean's the same not enough fuel.
But, since you say gas comes out of the front of the carb's means your blooding out.Neddle valve stuck or your floats are to high.I'm surprized you haven't had a fire yet.
Last,
Here,if you have to choke it to start it?Means you need more fuel floats too low.
If your carbs are overflowing with fuel means your floats are to high as too much fuel.
So,I can't tell if you need more or less fuel as what you explained is going on.
You don't need a boat expert for this 1973 carbs.You need a Harley biker to do those carbs.
 
When im at WOT and let the throttle back it will die out.... I go to start and it will not start at all. I pull the choke and it starts for a sec then dies. Soon as I push the choke off and go to start it fires right up.... thats why i think its getting to much fuel... instead of not enough fuel. It runs like a champ at home with the muffs on.... no problems at all. It only has problems when the motor is under a load. I dont run the motor with the choke on
 
kimcrwbr1 said:
If the reed valves were bad it would spit fuel out the carb/s when running. While it is running try disconnecting the plug wires one at a time with a good pair of insulated pliers to see if the rpm drops even short one cylinder. If you have to choke it warm that is a sign of a vacuum leak in the intake somewhere. Maybe pull the carbs again and check the mounting surface with a straight edge I glue a piece of 200 grit to a flat board and slowly work it in one direction until it is good and flat. allways use a new gasket and just get the nuts good and snug do not overtighten. After the engine fully cools down snug them again overtightening carb bolts is a common problem it bends the ears on the carb so it dont get a good seal.
Click to expand...

But wouldnt I here a vacuum leak?
 
I think im gonna take the carb's off and just bring them to the marine shop.... The whole purpose of buying the rebuild kits and doing them myself was to save from paying the marine shop $80 an hour. But now i have no choice. I don't have the time to mess with it anymore.
 
I think you need to do the test kimcrwbr1 suggested. These will run on two cylinders.
That would explain the lack of power and the overflowing gas. Is gas flowing out of all or 1 carb?
Actually I can't belive no one suggested it but spark and compression test here are mandatory.
You and the marine mechanic could rebuild them 100 times correctly and the engine still will run like crap if you are missing spark or compression on a cylinder.

I am a complete novice but I rebuilt my 73' 65 HP Evinrude (13 year sleeper) carbs according to the 73' factory manual.
But I didn't bother until I had compression and spark tested. Then every fuel component was replaced.
 
Last edited:
Float valve adjustment really is not the cause of this.-----------------Check the compression.------Check to make sure there is spark on all 3 ( needs to jump a gap of 7/16" ) for a proper test.-Check the flywheel key.--------Note , they all sound good to the untrained ear running on a hose.
 
jim18611865 said:
I think you need to do the test kimcrwbr1 suggested. These will run on two cylinders.
That would explain the lack of power and the overflowing gas. Is gas flowing out of all or 1 carb?
Actually I can't belive no one suggested it but spark and compression test here are mandatory.
You and the marine mechanic could rebuild them 100 times correctly and the engine still will run like crap if you are missing spark or compression on a cylinder.

I am a complete novice but I rebuilt my 73' 65 HP Evinrude (13 year sleeper) carbs according to the 73' factory manual.
But I didn't bother until I had compression and spark tested. Then every fuel component was replaced.
Click to expand...

Gas is flowing out of all 3 carb's.... and i checked compression like 40 times on this motor. and its always 130-130-130. and has spark on all 3 cylinders
 
kimcrwbr1 said:
The best way to find a vacuum leak is with a piece of vacuum tubing stick one end up to your ear as search around the gaskets with the other end the hissing will get louder the closer to the leak. Put a good strait edge on the carb mount surface and hold it up to a light you probably did fine with the rebuild how tight did you tighten the carbs down did you go past snug?
Click to expand...


When i tightened the down i made sure they were very snug....
 
Have you looked at the reed valves ?-------Have you checked for spark that will jump 7/16" on all 3 ???----The term " good spark " means nothing to me.----Run this motor with a timing light hooked up ( one cylinder at a time ) and see how spark behaves.--------Remove cover in front of carburetors and at full throttle observe fuel coming up the main jet ( strong flashlight required ) -compare the 3 cylinders.----------You may have blockage in float valve or the wee hoses.--Have you checked the fuel pump diaphragm ??-----------Simple tests give good results. Jumping up and down beside the motor gets you nothing.
 
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