225 Johnson bogs when throttle applied

[jakester136]

Hi guys,

I have been fighting this thing for a couple weeks now and still haven’t been able to figure it out
its a 1997 Johnson Venom i recently bought that had a new power head a few years ago and has basically sat since. It starts up easily on cold start and idles. It always fires up with a bump of the key after the first start of the day. Problem is when I go to give it any throttle it will bog out and sometimes die. If I feather the choke on the key just the right amount it will snap out of it and hop right up on plane and runs like a champ on top end and will spin 6k rpm easily.

so far I’ve done the following.
pulled all the carbs apart and thoroughly cleaned- no sneezing or leaking through carb throats while running, there does appear to be some residue around the carb bodies and gaskets after running, may be normal? Not sure
link & sync - butterflies fully closed at idle, .005 between roller and throttle arm
set timing @ 4 ATDC idle and 18 max advance
All new fuel lines to carbs, pump and primer bulb.
the fuel/air screws were all over the place when I got It I set them all 5 turns out, have tried 6 and 7 turns out with same result.
Compression test is 110 across all cylinders with basically no variance
disassembled and cleaned primer solinoid
diassembled and inspected fuel pump. Mine is the fuel pump only version with no oil side,
I pre-mix 50:1
fuel tank vent inspected
verified my TDC of Cyl #1 correlates with timing pointer.

I’m at a little bit at a loss, since feathering the choke gives it a surge of life I’m still convinced it’s a fuel issue. I’m just about to pull all the carbs off again and see if I missed something ����*♂️ But I wanted to gather all the input I can get, I’ve been dealing with loopers for a while but I’m still no expert

[ChampioNman]

What's your idle rpm in gear and in neutral?

[86 inches]

That drove me insane. Tried everything. Seems like changing out the recirculating check valves was last on my list of things to try just before it threw a wrist pin.

[jakester136]

Idle RPM if tach is accurate is about 800, 650-700 in gear

[jakester136]

Where are the recirc valves and how do I maintenance them?

[ChampioNman]

https://www.marineengine.com/parts/j...p%3B+Crankcase Item #11 they are in the front half of the crank case.

[Almag6]

I thought they were pricey a couple years ago @ $25 ea. $43 now? Wowza!

[darryl1966]

im currious to see the fix, I have a 1996 ,225 Venom doing the exact same thing , runs perfect till you drop it in gear and touch the foot throttle, then it flops , feather it some and it may get on plane , if it does plane out, it runs like a scalded ape .

[AndrewM-Fishing]

Any update on this? Having the same issues on a 96.

[darryl1966]

taking mine tomorrow to have the carbs gone through , no one seems to know exactly where to start

[Ed Brabant]

2001 225 HO same same bit lower on compression. Was going to Lync and Sync today raining like chickens and Pigs dam tropical storm. Clearing this afternoon. Rolling @ 4:30am headed to NH for a T. Will be following thread closely...................

[Ed Brabant]

May be a real dumb question but what is the purpose for the check valve. I know what they are and how they work. But on each carb has one. When they work 100% block any leakage is NG and will give me fits. Oh and a fyi don't blow carb cleaner in the wrong side. Will blow back in your face and eyes and it tastes horrible. Trust me.........................................

[86 inches]

May be a real dumb question but what is the purpose for the check valve. I know what they are and how they work. But on each carb has one. When they work 100% block any leakage is NG and will give me fits. Oh and a fyi don't blow carb cleaner in the wrong side. Will blow back in your face and eyes and it tastes horrible. Trust me.........................................

They scavenge fuel from the intake sending it to be burned in the combustion chamber.

Here is an old thread where Rusty and ChampioNman talk about them. Its a V4 they are talking about but its the same for the V6 looper.

http://www.bbcboards.net/showthread.php?t=1488

[86 inches]

And I don't know if changing them - or cleaning them - will help the OP. It's just one possible issue among many that can cause the bogging down problem.

I know I tried everything when I had this problem. We rebuilt the carbs, considered vapor lock, did some other things that I don't remember. My mechanic even took it to the lake and ran it himself. Swapping out the check valves was next on the list before it sucked in a wrist pin and blew the powerhead. I had been dealing with that problem for so long and it was so frustrating that it was kind of a relief when the thing finally grenaded. After some thought, I got the G2 and that was that.

[omcforever]

They scavenge fuel from the intake sending it to be burned in the combustion chamber.

Here is an old thread where Rusty and ChampioNman talk about them. Its a V4 they are talking about but its the same for the V6 looper.

http://www.bbcboards.net/showthread.php?t=1488

They also provide lubrication for some crossflows as well using recirculated fuel to main bearings via the hoses and engine pulses.