1986 225HP V6 Looper Hard starting, bogs, stalls

[imthemedic]

Re: 1986 225HP V6 Looper Hard starting, bogs, stalls

Check the fuel system once again for possible air leaks...
Then it sounds like it needs a Lync and Sync done. Does it idle low in neutral around 600rpm and dies? If so try pushing the primer to see if anything gets better. Reason I say Lync and Sync is whne you push throttle forward the timing plate moves and cause the motor to run ruff if not properly tuned.

 

[Greg_E]

Re: 1986 225HP V6 Looper Hard starting, bogs, stalls

When I can get it started, it idles at about 650RPM. I'm bringing some clear tubing with me to check for any air leaks. When it would start to bog I could sometimes get it to stay running by pushing in the primer. I have not check the lync and sync yet, but at a quick look, all the throttle blades are in the same postion and are all closed in neutral.

 

[imthemedic]

Re: 1986 225HP V6 Looper Hard starting, bogs, stalls

Definate air leak somewhere. However you need to do the lync and sync. I would bet that the timing is off when you give it throttle. More than likely the cam plate is touching the cam follower or atleast in the wrong position or timing. If so it will adjust timing to much before opening the carbs basicly. First try to locate the possible air leak then get a manual or take it to someone and get the lync and sync done.

 

[Greg_E]

Re: 1986 225HP V6 Looper Hard starting, bogs, stalls

I'm certainly not ready to rule anything out, but the engine runs fine out of the water. Right now, I'm leaning towards the problem that clanton described with the 1986 long shaft 225's, but I would love it to be something as easy and inexpensive as an air leak.
The first thing I bought after I got this engine was the OMC manual. The cam follower is close, but I don't think it's touching the plate. I can easily roll it with my finger. I'll have some time over the weekend to look at things.

 

[clanton]

Re: 1986 225HP V6 Looper Hard starting, bogs, stalls

The 87 carbuators have a smaller bore.

 

[Greg_E]

Re: 1986 225HP V6 Looper Hard starting, bogs, stalls

OK Here's where I'm at now.

I knew I had one cylinder not firing or firing intermittently, so I decided to fix that first, as it was the easiest to troubleshoot. Without going into all the details, it turned out to be the stbd side power pack intermittent on the top cylinder. This made a very minor improvement in how it ran.

I checked the link and sync, and everything looked good, but I went though the adjustments anyway. No change

I had changed the fuel pump from the three wire to the four wire pump before I launched the boat. I didn't think the pump was bad, but just to eliminate it as a possible cause, I swapped it with a known good fuel pump from the 1988 that I had removed for this engine. Also checked all the fuel line connections in that area. and everything was good. No change

As I had mentioned earlier, the carbs had been pulled and cleaned previously, but I wanted to get a better look at all the connectors and fittings, so I pulled them with the throttle plate assemblies attached. The only thing I found was the plug for the test port on the intake manifold was deteriorated. It was hard and cracked, but was still in place, so I don't know how much air could be leaking past it. I did replace it.

After finding very little that I could point to as causing the problem, I made a decision to try the carbs from the 1988 engine. They do not have the smaller bore diameter that the 1987 carbs have. I didn't have an accurate way to measure them, but as close as I can tell, the bore diameter on the 1988's are the same as the 1986"s. The orfices are different though, along with any other changes, that I'm not aware of. The engine runs much better, although not 100%. The engine will some time start as soon as I hit the key, and other times it will not. I can always get it started now, but sometimes I have to put it in neutral, and advance the throttle to get it started.

It will ocassional bog and stall, and that only seems to happen if the engine sits for fifteen minutes or so. It acts as if it just runs out of gas. If I work the throttle as it's dying, I can see the rpms pick up for a split second, but it just contiues to die. I did check the primer bulb on the fuel tank and the ball stays hard so The check valve seems to be good. I can then restart it let it idle for a minute, and it will run like nothing is wrong. At least I can use the boat.

I tried ajusting the idle timing and the cam follower to see if I could get it to start better, but neither thing had any effect, so I put them back where I started. Idling in neutral at the dock (which is not the proper way to check the timing) It is 6* ATDC, at 650 RPM, and it seems to run best at that position.

It was brutally hot this weekend, so that's as far as I got.

 

[ezeke]

Re: 1986 225HP V6 Looper Hard starting, bogs, stalls

I see several references to flywheel charge magnets, but it's the sensor magnets at the center of the flywheel that cause ignition problems. You need to remove the flywheel to check the positioning. Here's a link for the diagram: http://cdielectronics.com/downloads/troubleshooting guide/OMC Flywheel Trigger Magnet Location.pdf

 

[Greg_E]

Re: 1986 225HP V6 Looper Hard starting, bogs, stalls

I see several references to flywheel charge magnets, but it's the sensor magnets at the center of the flywheel that cause ignition problems. You need to remove the flywheel to check the positioning. Here's a link for the diagram: http://cdielectronics.com/downloads/troubleshooting guide/OMC Flywheel Trigger Magnet Location.pdf

I'm not sure I'm following your train of thought on this. If the sensor magnets had shifted, wouldn't it follow that it would run poorly all the time? I came here for advice, so I'm willing to listen to anything you and others have to say, but I'm not seeing the connection. Can you elaborate?

Sometimes I can just turn the key and it will start and run fine. Once it is started and running, it will run perfectly. I can pull it back to an idle let it sit there, and then take it back up on plane with no hesitation or bogging. It will do that all day long, as long as I don't shut the engine off. The only time it will bog and stall is if I turn it off and it sits for a while, and it will not do that every time. After a couple restarts it will stay running and I'm good to go, until the next time I shut it off, which makes me think it's more of a fuel issue than electronics malfunction.
The two things that I did, that made a huge improvement were replacing the plug on the intake manifold test port and installing the 1988 carbs. I did both at the same time, so I can't say for certain what caused the improvement, but the cap was still in place even though it was rotted, so I don't think it could have been leaking that much air, if any.
The 1988 carbs are not the ones recommended in the service bulletin to fix the problems I was seeing, so it could just be the need for the 1987 smaller bore carbs, to finally resolve all the issues. I just don't want to overlook something simple. I'm sure even if I can find some used 1987 carbs they won't be cheap and will need to be rebuilt.
One mechanic suggested squirting gas from a squeeze bottle into the carbs when it starts to die to see if it is running out of fuel, or getting too much. Quite frankly, I'm not real keen on hanging off the back of the boat, and sqiurting raw gas into the carbs.

 

[Livewire]

Re: 1986 225HP V6 Looper Hard starting, bogs, stalls

If you have the time, read through the post that I started. It sound kind of the same, one other thing that I will try; I will be replacing the fuel prime bulb, in the vest readings I don't recall much about it, a friend of mind was having fuel restriction problems and someone suggested to replace the bulb, he did and it corrected he running issues. Below is the title of my post...

"88 GT200 (J200STLCCM) Boggs then dies 3 out 5 times... "

I hope this is some help to you...

I'll be watching you on yours...

Later

 

[Greg_E]

Re: 1986 225HP V6 Looper Hard starting, bogs, stalls

Both the yard mechanic and myself checked the primer bulb and it seems to be OK. When I pump it, the bulb will get hard, so the check valve seems to be working, at least while pressure is being applied. Maybe it is slowly leaking back. I may just replace it, so I can check it off the list. It's an inexpensive and easy to change part. I don't want to just throw parts at it, but my time at the boat is limited.

Livewire,
I did read your thread. Unlike you, I cannot push through the the bogging by pressing the prime button on the key switch. If it starts to bog, it will stall.

 

[jonesg]

Re: 1986 225HP V6 Looper Hard starting, bogs, stalls

I cannot push through the the bogging by pressing the prime button on the key switch. If it starts to bog, it will stall.

then its the ignition dying out.
Try a timing light to watch if spark is dying .

 

[Greg_E]

Re: 1986 225HP V6 Looper Hard starting, bogs, stalls

I have already done that. I have strong spark at all six plugs. None of them are firing intermittently. Unless someone can give me a logical explanation as to why they think it's ignition related I'm not leaning in that direction. An intermittent ignition problem would be just that. Intermittent. It would most likely get worse as the RPM's increase. It would not happen just when I try to restart and try to accelerate the engine after it sits for a while.
I'm still leaning towards an air/fuel issue, unless convinced otherwise.

I have the factory service manual.

 

[Greg_E]

Re: 1986 225HP V6 Looper Hard starting, bogs, stalls

My apology for the long delay between posts. Life has been getting in the way of my boating, and I just haven't been able to get down there.
This weekend, I changed the fuel line and primer bulb. After sitting for three weeks it started after a few tries and idled perfectly which I would consider to be normal, and it did that three days running. The engine is running great through the entire rpm range and will run all day, unless I turn it off. If I shut it off,while I'm drift fishing, it doesn't want to start back up. I can always get it restarted, if I squeeze the primer bulb and give it some throttle.
It seems like the fuel is draining back out of the carbs, but the primer bulb is rock hard when I prime it. There are no fuel leaks that I've found. At this point, I can live with it for the rest of the season, but I would like to fix it. What am I missing?

 

[Livewire]

Re: 1986 225HP V6 Looper Hard starting, bogs, stalls

Greg,

The following may appear as a broken record, but have you got to lose?

It appears to me that there is a problem with the floats, if you have changed the primer blub, there is a check valve there. So the carbs should NOT be draining back to the tank. This sounds crazy, pull the carbs off (again) and check the float levels and the valve seats, a small piece of trash, anything will allow the fuel to drain out, and while you are there pull the high speed fuel jets and clean them out with carb cleaner, make them jokers look like brand new, they may be clear when you look at them, if they are dirty (or stained looking) that is restrictive. Then while the carbs are off the throttle plate, (I only removed the carbs), re-adjust the throttle plates, (LINK & SYNC) follow the chart in the factory service manual for fuel & primer hose routing, make sure this is correct. Then follow the timing setting for the WOT and idle timing. This alone made the biggest improvements in my motor. The only other thing that comes to mind at this moment is the little check valve that hooks to the fuel pump, pull that joker and hose it out.
Hurry back I will wait to hear the results.
Well, don?t just set there with your teeth in your mouth, get going.

 

[Greg_E]

Re: 1986 225HP V6 Looper Hard starting, bogs, stalls

Where is this check valve that hooks up to the fuel pump? I was unaware that there was a check valve in the fuel line near the VRO pump.
I did the link and sync when I replaced the 1986 carbs with the carbs from my 1988 engine. I do need to check the idle timing and WOT timing. I have the stop for the WOT timing set conservatively, until I get that done, and I'm not pushing the engine.

 

[ezeke]

Re: 1986 225HP V6 Looper Hard starting, bogs, stalls

The only check valve outside the pump would be in the primer bulb or the anti-siphon valve at the tank.

There is a pulse limiter but that only functions when there is excessive pressure from the engine unless it is clogged.

 

[Livewire]

Re: 1986 225HP V6 Looper Hard starting, bogs, stalls

Where is this check valve that hooks up to the fuel pump? I was unaware that there was a check valve in the fuel line near the VRO pump.

The valve that I am speaking of is located on the vacuum hose that hooks to the bottom to the fuel pump and threads right into the engine block. Someone chime in with the proper names of the parts.

Another thing, check the tigger wires from the power pack, make sure that they are routed away from the other coils and spark plug wires. I was picking up a ghost signal on the #1, after emailing CDI with the problem they responded with check the wire routing.

I pulled the carbs off twice, doubled check the LINK & SYNC and I had missed a step or two the first time around, that was because I was working from memory rather than just going back upstairs to re-read the book...

I just finished with getting the idle timing set this weekend, the motor is running almost as new...

 

[ezeke]

Re: 1986 225HP V6 Looper Hard starting, bogs, stalls

The 1986 loopers don't have QuikStart, so it's helpful to use the warmup lever to advance the timing if you have it. Otherwise you need to use your shift override to advance the timing when the engine has cooled.

 

[Livewire]

Re: 1986 225HP V6 Looper Hard starting, bogs, stalls

The only check valve outside the pump would be in the primer bulb or the anti-siphon valve at the tank.

There is a pulse limiter but that only functions when there is excessive pressure from the engine unless it is clogged.

Thanks for the follow up... I can see in my mind is one thing, getting it to the keyboard is another...

 

[Greg_E]

Re: 1986 225HP V6 Looper Hard starting, bogs, stalls

The 1986 loopers don't have QuikStart, so it's helpful to use the warmup lever to advance the timing if you have it. Otherwise you need to use your shift override to advance the timing when the engine has cooled.

Thanks for the replies guys.

That is correct. This engine and the 1987 engine I had on my other boat needed to have the throttle advanced to get them running when they were first started. The 1987 would start in neutral when it was warm. This 1986 will not. 1988's with the quickstart will start in neutral with a little prime.

The pulse limiter is new.

I'm going to try smaller idle air bleed orifices for the low speed idle when I get the chance. The problem seems to get worse when the engine is hot. Since I changed the carbs, I don't get the lean sneeze and bogging, but maybe it's just not pulling enough fuel when I try to restart. I'll also check/change the anti siphon valve in the tank.

I think Clanton was correct with his diagnosis, but I can't find any 1987 carbs, so I'm hoping that with a little tweeking, I can get these 1988 carbs to work.

If it comes down to pulling the carbs apart, it's going to to wait until the season is over. I get precious little time to use the boat as it is, and I'm not spending the summer hanging off the back of the boat. I did that last year!