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1986 evinrude 140 v4 vro struggles to get on plane

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Evinpoo

New member
Hi, I’m new to the forum and had some questions about by 1986 evinrude 140 hp vro. I bought the boat 3 years ago and have always fought the problem of getting the boat on plane. The Boat idles fine, but when you try to get on plane and push the throttle wide open it bogs and dies. Some times you can Slowly advanced the throttle and get the boat to pop out of the water but other times it will kill the engine. When the boat does get on plane it seems to hesitate and then launch out of the water or hesitate and kills the engine. I have replaced all the fuel line, gone through the carburetors And rebuilt them, replaced the ignition coils, replace the spark plug cables and the spark plugs,And most recently I’ve replaced the VRO pump with a fuel pump and premix my gas. I’ve been thinking it might be a timing issue but I’m not for sure, any help would be greatly appreciated. Thanks!
 
Not there to see your boat condition -----Or the prop pitch.----Or if the boat is water logged.------But post your compression numbers first.
 
Compression is 125 is all cylinders and the prop is 14 x 19. I don't believe the boat is water logged. The boat is a 17 ft 171 phantom forester. I have pictures and videos of how it runs on the water but I'm having problems trying to upload them.
 
Use a timing light one cylinder at a time.----Observe the flashing light.-------Sounds to me that it has an ignition miss and not running on 4 cylinders !
 
Ignition related and check compression as these motors scuff the piston on exhasut side due to bridge port design..
 
Okay I am planning on checking the timing. I have a manual for the boat and it Describes maximum spark advance adjustment. I haven’t ever messed with timing before so I just wanna get a good idea of what I need to do. The manual says to have the boat running from 4500-5000 rpms with a load, I was planning on doing this on the lake with a buddy. My full throttle spark advance says 18 degrees before TDC, so when I’m running at full throttle i should see the 18 degree mark at the timing pointer when I have a timer gun on it? Also does the Type of timing gun matter? I have older Stewart Warner gun that has a positive and negative for power and the clamp that goes around the spark plug wire and it doesn’t have any adjustments.
 
I took the boat out and adjusted timing didn't make a noticeable difference so I left them at what I started. I think the problem is fuel related now because I was messing with primer solenoids red lever and the boat would get on plane if I would keep using the primer. I know when I rebuilt the carbs 3/4 of them had cracked in fuel pick up from the bowl (emulsion tube) and I'm wondering if that would result in my problem. I cannot find replacement parts for the emulsion tubes so I think i might have to buy a carb body for this. The cracked ones seem to be made of some fiber material, does anyone know if you can replace the emulsion tubes?
 
Hi all, know it’s been a while but I found some time to work on my boat. I ended up buying new carburetors because the emulsion tubes were cracked on mine and that ended up fixing my problem. The engine wasn’t picking up enough fuel while attempting to get on plane, but it works good now!
 
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