Fuel coming out of the hose connected to the vapor pump 0433352

Bannister 6905

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Hello all.

1999 Johnson V4 2-stroke with VRO - When priming the carbs with the bulb, raw fuel squirts from the hose exiting the vapor pump. Carb on the top left seems to be starved for fuel. Any ideas as to what may have gone wrong? Many thanks.
 

Faztbullet

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Float stuck open in VS as fuel should not reach vapor pump if float is closed
 

Crosbyman

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see how a typical VST works on a later version on a ETEC... around 4:50 min.

 

Faztbullet

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Here is link to how 60° vapor separator work
 

Bannister 6905

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OK, so I eliminated the VRO and rebuilt all 4 carbs with the BRP oem kit parts. checked float levels and completely cleaned . Now have fuel flowing the overflow on port-side top carb and massive flooding. pumping bulb once after bowl is empty nd fuel starts coming out of the overflow. other 3 seem ok.
removed that carb, reinspected , reassembled and problem persists - massive flooding and no start, I am kind of at a point where I am losing faith. What could I be missing? I feel like it's a float problem, but it tests good on the bench using compressed air. Any advice will be appreciated.
 

Chris1956

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Normally carb overflow is caused by a faulty inlet needle and seat or incorrect flat adjustment, or perhaps a float that leaks and fills up, or jams in the bowl.

However, a lot of those engines have plastic carbs. The bowls warp and all sorts of sealing issues occur.

The warpage is obvious, if you put a steel ruler across the bowl. The cure is to replace the carb bowls. Remember, the main jet usually lives in the carb bowl. Be sure to switch it over to the new bowl.
 

Bannister 6905

Petty Officer 2nd Class
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Jun 5, 2015
Messages
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Normally carb overflow is caused by a faulty inlet needle and seat or incorrect flat adjustment, or perhaps a float that leaks and fills up, or jams in the bowl.

However, a lot of those engines have plastic carbs. The bowls warp and all sorts of sealing issues occur.

The warpage is obvious, if you put a steel ruler across the bowl. The cure is to replace the carb bowls. Remember, the main jet usually lives in the carb bowl. Be sure to switch it over to the new bowl.
No warpage, float / needle are free. Now, it's not flooding and there's fuel in the bowl, but no run. Will start and run briefly on carb spray. I am out of ideas, period. Thanks for your advice.
 

racerone

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How did this motor run for you last season ?----Is the electric primer valve working ?----Are you pushing the key in and holding it in while cranking for cold starting ?
 

Crosbyman

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problem seems to have migrated Now, it's not flooding and there's fuel in the bowl, but no run.
can we presume the VST issue has been resolved ... ? findings ???

carbs are full now .......... fuel inlet needle is working.......... starts on carb cleaner
but will not run...presumably not pulling in fresh fuel from the carbs !

..back to basic checks

have you checked/cleaned the carbs , jets passages etc...
we are back to "not starting"
 

racerone

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Learn how the electric primer valve works.----Test the electric primer valve.-----Or test with electric primer valve in manual mode , squeeze bulb 2 times.----Put valve in run mode and try and start the motor.-----Have battery fully charged and load tested as well.
 

Chris1956

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If the motor runs on some fuel sprayed in the carbs, the carb idle passages/jets are likely clogged. Your motor has the idle passages and needle in the throttle body. There are covers on the sides of the throttle body, which can be removed exposing the idle mixture needle. I used some gumout spray to clean it and the idle passages. Also, make sure the "spaghetti" gaskets seal the passage where the fuel goes from the carb bowl to the throttle body. I had trouble getting carb kits with the exact right gaskets. They were close, but not quite right.
 

Bannister 6905

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Update - can now get it to run briefly, and am getting a "milkshake" flowing from the exhaust. Pulled plugs and they look clean - maybe too clean. Is the "milkshake" a sign of water mixing with the unburned fuel? The carbs were carefully cleaned before I started this adventure. This motor is "new" to my son and was sold as "running" to him, but has been hacked up over the years. Compression is 120 on each cylinder, which was his reason for buying it in the first place. Now, Dad gets to fix it...
 
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