1997 new to me Johnson 90hp outboard bogs down above 1/2 throttle

[jakedaawg]

Did you do the fuel vacuum test?

 

[James R]

I have just recently solved a very similar problem on a 97 90HP. Drove me crazy. Would go up to around 2200 and then die if I didn't throttle back. One problem was the fact that someone had removed the VRO and replaced it with a single standard pump. Fixed that but the problem remained. Turned out that fuel was not getting to the carbs. Everything before the carbs was working because having removed the carbs there was no fuel in them and turning the motor over, fuel shot out of of all manifold feed ports to the carbs. Cleaned but could not find any dirt in the carbs. Rebuilt with new kits, tested and Bingo! she flew again. It is supposition on my part that fuel was getting past the string seals and into the carb throats without going into the carbs.
Food for thought.
Hope this helps

 

[WhiteRice]

Had something VERY similar to mine as well. It ended up being a few things but in the end, the main culprit was the powerpack.

Also, to James R's point...
I will say for simple fixes: double check your float needles to ensure that each bowl is getting fuel and then check your highspeed jets for obstructions. I had everything working great after my powerpack swap and then I had a piece of junk keep my float needle from operating correctly and I had your same symptoms. I almost lost it thinking the shop installed a faulty unit but I was able to fix it with some help from the tech over the phone.

 

[jstme123]

Thanks guys for all the help, still have the issue and even the mechanic cant figure it out....guess its going up for sale

 

[oldboat1]

Good case for testing with timing gun -- hook to wires one at a time and operate boat, leaving gun when you can see the flashes. No flashing means no spark. (Just a variant cylinder drop test while underway -- kind of difficult/dangerous to be back there pulling plug wires.)

 

[Viking NH]

Idles great, runs great up to 1/2 throttle or so then above that bogs down immediately to a idle even though the controls are above 1/2 throttle. If i back it off and throttle up again it will run fine up to half throttle but not above, what could it be? There was also a intermittent alarm buzzer which i believe is the low oil warning (beep every 20-30 seconds or so) but only beeped at idle, not when throttling up. Any help is appreciated.

I'm late to the game but had the same experience with my '84 90hp Johnson V4 outboard. One of the two ignition coils went bad so replaced it (5 minutes work) and runs great again.