TOPIC: Help with my Jonny

The title may throw some of yall off, BUT I have tried to post in the "JEGO" place several times to no avail. I think all the best people on this site are found in this forum. I could use some help from you kind fellas if you can spare a moment or 2 to reply it would be greatly appreciated.

My boat (recently purchased) has a 88 johnson 150 vro outboard (NOT THAT THIS SHOULD MATTER MUCH). I just am hoping for some basic possible diagnoses of what could be going on here. My last time out she really did not want to start up at the dock, took quite a few tries to get going, then she stalls out at a very specific rpm range, just past first gear, as soon as you get a bit past the first gear point on the throttle she starts to bog.....Then I noticed if I use the prime function at the key (pushing it in) she trogs past this awkward rpm point ok. My buddy thinks she runs rich, but to me this would indicate a too lean condition, I have ordered a new fuel filter, but could a bad fuel pump diaphragm also be a possibility ? I am planning on running a compression test asap also, but was hoping to hear what you guys thought might be going on. Thanks again

I'd try going richer on the low speed needle if it has an adjustment for it. If the fuel pump diaphragm was bad I would think it would continue to run poorly at high speed

Thanks Doug, I am pretty sure it does NOT have an adjustment for either needle.

I know my old car acted like this when fuel filter got dirty. Could ease up to speed with no problem, but try to climb a hill or accelerate fast and it would fall on it's face and sometimes stall. New filter and problem solved for me. Not sure if same applies to outboards. I think I had also heard people talk about certain aftermarket fuel cans and hoses that worked well on smaller outboards, but struggled to keep enough fuel fed quickly to bigger outboards. The experts would have to chime in on that subject as I cannot guarantee I heard that right. Our old in-line mercs did this when the squeeze ball would go bad. When we bought new ones, the problem went away. Ethanol in gas recently ate the inside of mom's 50hp mid 2000's merc squeeze ball that ran like that. Got a new ball...cut the old one open and it was coming apart inside and a chunk of rubber was blocking the flow... likely from the ethanol gas. Now only Non-ethanol gas for recreation stuff. Just our experiences. Best of luck resolving your situation.

It's lean. If the fuel primer ball is collapsing=obstruction in the tank. If the ball is losing prime (like you have to pump it up again to keep it running)=collapsed line, clogged fuel filter, some other obstruction or a bad fuel pump. If none of the above. Rebuild and thoroughly clean the carbs. Then see what you have.

Thank you Clyde. The new filter should be here today or tomorrow. If that dont help I will replace that primer bulb (it does not seem to stay hard ). If it still persists, I will test the pumps for faults, if non are found I will move to attempt rebuilding the carbs. Gonna start with a compression test this week too. Will keep yall updated, thanks to all who have jumped in here to help.

While running, the bulb will not stay hard.

Hey guys, I could still use some help with this thing. Spoke with a old tech recently. He is in the mountains so deals with these kinds of problems often. He told me that johnson/brp does NOT recommend changing the jets on these motors for altitude. He confirmed the conclusion I had come to; Since my engine is suffering from a fuel starvation issue putting high altitude jets on would make my problem worse, as high altitude jets are always down sized, thus restricting the fuel even more. I am hunting for a fuel pump, but am not sure this is the culprit, since it runs fine at higher rpm/ throttle. Its just starting and low speeds it really struggles with. Gonna post up in as many threads as I can to get some suggestions. Thanks again