Rebuilt 1996 Johnson 225 Looper Idle and Bog Issues

[jreddic4]

Confession: i have been reading this forum for a while and have learned a whole lot especially from ChampionMan and Seahorse and many others, thank you all for your time. I'm really stumped and needed to make a post so here goes:

Starting with the current problem and a long backstory to follow:

Motor:Model J225TXEDE 1996 Johnson 225 Ocean Runner,

Current Issue- Motor will not idle and bogs at mid throttle. Cranks immediately and will run without additional choking during quickstart, and will keep running if bump choke when quickstart drops out. Also will accelerate if choke when it starts to bog. Top end is excellent- will turn 5900 RPM WOT. Tried opening up idle fuel mixture screw and it will idle at 9 turns out, but 5 is spec and still bogs mid throttle. Compression is good 120 +/- 10 on all cylinders. Timing is correct and all cylinders firing correctly at correct time. Has idle issue warm or cold. Most recently realized i included the nylon washer under needle seat of carb and mine has raised lip and should not have used washer so removed- idle seemed to improve some but still 9 turns on mixture screw to try to idle and bogs mid throttle- didn't even think about idling before removing washer. Emailed Boyesen Tech support to verify i read the instructions for installing the reeds- which i took to mean i should increase idle mixture by 1 turn- from 5 to 6. Boyesen Tech support has emailed back and said no i need to replace idle air orifice currently 30 on front of carb, downsizing by five sizes to #25. My OEM service manual calls this an intermediate air orifice, so i asked boyesen if they were sure and they keep calling it an idle air orifice and directed me to a marine engine.com diagram that calls it an idle air orifice. In looking at it it does connect to the idle circuit of the carb, so maybe this is my fix but at $35 each i wanted a second opinion before wasting that money. Also i realized i need to order updated drain plugs for the carb, but it appears people sell the old and new style under the same part number or maybe i am looking at it wrong. Also in researching this i see i should increase jet on Cylinder 2, all main jets presently 72D, so i have ordered a 74D to swap on number 2. Today i took carbs and throttle body back off to go back through but don't think i found anything but really cleaned everything thoroughly and will get back installed sometime this week in the afternoons. The carbs had sat over winter, when as you will read below i had to tear this motor back down over the winter.


Backstory:
Fully Rebuilt Motor last year with a new everything except Flywheel, Rectifier, and some recirculation fittings, otherwise its been replaced or rebuilt, including swap to Boyesen Reeds- which I'm starting to wonder if are my problem - not broken just difficult to tune. I'm not sure if motor idled correctly pre-rebuild as I bought a boat that came with a blown motor and decided to rebuild when it cranked and ran with a completely blown Cylinder 1 piston and the seller said he had been driving it knowing it was blown for a year or so, i can't remember if idled then or not as i didn't keep driving with blown piston but thought if it wanted to run that bad i would fix it. Bored oversized, sleeved a couple cylinders, replaced with Wiseco pistons. Stator was leaking tar so replaced, timer base didn't check to specs so replaced, decided to just replace coil packs, power pack failed some tests so replaced, checked flywheel magnets reglued one some others appeared to have already been reglued but were in good shape, inner magnets look good, rebuilt carbs, replaced gaskets on throttle body idle circuit. Ran motor with rough idle last year until started surging and checked compression after 40 hours on that rebuild and cylinder 2 was blown. Tore back down resleeved just cylinder 2 all other were good and now entire motor is bored 20 over running wisecos on all pistons. I realize now it might have eaten the piston due to lean idle, but think i caused the issue one day when i ran the motor without the water pump restrictor fitting where you connect the water hose, i had run at home on the hose and forgot to reinstall the fitting, motor ran hot and shut down, i realized what happened and quickly put the plug back in and motor cooled down and ran fine for a while but think damage was probably done given that number 2 runs hot anyway. The machine shop said it looked like i left a piece from the previous rebuild/blowup in there and came out and beat the head and top of piston and blew out the exhaust but i hadn't remembered the overheat at that time and didn't mention it. Water pump was rebuilt and is very strong, thermostats were rebuild also. Sorry for the long story and I'm sure i left something out because this one has been a real journey.

[Simply_M]

I have a 93 Johnson 150 and it suffered idle issues (lean sneezing) and I found that air was being sucked in around the shafts of the throttle bodies. Would still take throttle and accelerate though.

[jreddic4]

What was the fix, I’ve completed link and sink previously and will again when reinstall carbs. Butterfly screws are all tight.

[ChampioNman]

Two completely different engine blocks and fuel delivery systems. Make sure the test nipple on the upper intake manifold is in place and the reed cages are fully secured to the intake manifolds and the reed cage gaskets are intact.

[jreddic4]

Just rechecked those items yesterday and all are good

[ChampioNman]

When you did the carbs did you clean out the calibration pockets on the throttle bodies and replace the gaskets? Try this also, reset the idle jets to 5.5 turns out and insert some tooth picks into the idle orifice for a test. The #25's can be had for $19.49 from marine engine # 0323003

[jreddic4]

I thoroughly cleaned all passages and replaced all gaskets, would the goal of the tooth pics be to completely close off the air orifice to test if that helps before buying new ones. I like the idea just wanted to be sure I do it correctly.

[Simply_M]

To stop the air around the shafts, I packed grease around the area where the shafts enter the throttle bodies. Made a huge difference.

[jreddic4]

I am rechecking all the recirculation system fittings now as another possibility in the service manual, I think I did this and replaced a couple fittings last year but an easy check where I am now before reinstalling carbs. Plan to get carbs installed will test run, then block air orifices with tooth pics and report sometime later this week. Thanks for the great idea and quick reply

[jreddic4]

Recirculation system checked out with no issues. I was pretty sure checked it last year but wanted to be sure. Hoping to get carbs back on tomorrow and probably test run Wednesday and will update.

[jreddic4]

I got it all back together tonight and found a 74d fuel jet for number 2 and a good deal on the six #25 air orifices so bought them and took with me to the lake. Started engine with original #30 orifices and idle was unchanged dying unless chocked. I inserted the tooth pics out of curiosity and idle improved, not perfect but better. I swapped out the air orifices to the #25s and left idle screw at 6, idled better but still dies down and speeds up with choke. I started checking timing again on all cylinders and number 6 was intermittently firing at the same time as #4, thought it could be wires touching but wasn’t, had an old coil pack so swapped it and it started firing correctly. I don’t know how this affected the firing timing but it did. It got dark as I was working and the timing light appeared to change speed of flashing but engine speed was constant and steady and all cylinders were firing at correct time. After swapping out the air orifices and coil pack I got the idle pretty steady at 8 turns out on the idle mixture screw. I had a thunderstorm in the area and never actually launched the boat so backed down the boat ramp and ran it on the trailer, but had it strapped down and gave it some throttle and it wasn’t bogging, so I think we are getting there. Thoughts on the coil pack causing the timing on that cylinder to jump around and is 8 turns out ok or is that implying something else is wrong. Current plan will be to fine tune everything on the water this weekend

[jreddic4]

To clarify all of this was done while on the trailer backed into the lake, with motor trimmed level.

[jreddic4]

Just realized the brass nipple on the coil that connects the #6 coil to the power pack wire must have been loose and fell off when I swapped that coil at the ramp tonight, I found the brass fitting down in the cowling, so maybe it was intermittently vibrating in the power pack wire boot and making connection explaining why the timing was jumping around. I guess the coil pack may not be bad but will check out.

[jreddic4]

So I took it to the lake and got it running great at 9 1/2 turns out on the idle mixture, then later in the day when running wide open it started cutting out and realized one of the metal plates on the front charge coil of the stator had come unglued and was touching the flywheel magnet, I had to break that piece off through the gap in flywheel with a screwdriver to get it to stop touching so I could get motor to run to get back to the dock. Stator was a sierra marine part purchased last year, so I will give them a call Monday to see if they are going to warranty it like their products say they will. Any have any experience with sierra warranty process, I have the receipt where I bought the part last year?

[jreddic4]

Update on Sierra Warranty Claim for the Stator, they just gave the best customer service i have ever received. I called in and they said to email them the original purchase invoice and a description of the failure, and 15 minutes later i received an email back with a reference number and said they would ship out the replacement part today under warranty. I am really impressed with the ease and speed of their service and thought i should share.

[jreddic4]

The story continues on this one. The rough idle and bog on acceleration issues continued after all adjustments and ended with burning a hole in cylinder 2 again. I have started to suspect I may have a fuel pump problem, as I rebuilt the factory pump with all omc parts replaced when I initially rebuilt this motor the first time but have since read not to try that as it never works right. I planned to buy the max rules pump to swap out and see how that goes but the machine shop said the burned piston looks like pre ignition to him. I had checked the timing and was set correctly so don’t know why that would be the issue. I have looked at the flywheel and the center magnet appears to have been RE glued at some point evidenced by a couple of uneven areas, but the outside lines match the cdi diagram for the motor. Looking for thoughts and suggestions on what to try when I get it back together again.

[ChampioNman]

If the cause of the original failure was not identified it will occur again. Sounds like the root cause wasn't found.

[jreddic4]

Understood, I keep thinking I have identified the issue why it failed but apparently keep getting it wrong. My current plan is to get it back together with a new fuel pump and see if the no idle and bog on throttle unless choked issue is gone and if not I’m ready to take it to a repair shop, but think it will need to go somewhere that really knows this model engine because I have followed the service manual and troubleshot back to front and am at a loss on what it can be if not the fuel pump at this point. I’m in Greensboro, GA and would be willing to take as far as needed if you have a recommendation for a mechanic. Thanks

[ChampioNman]

Looking at the block it appears that it has the cooling mod done to it.

[jreddic4]

I think you replied to the wrong thread in your reply above Championman.