1981 225 Black Max stator Questions

[rblanc9000]

Hello Gang, 1981 225 Black Max, Can anyone describe to me how the stater coils are wired to each other inside. Do the 3 high speed and 3 low speed coils work together or is each one responsible for producing a voltage to the switch block for a coil firing and just share a common wire . How many magnets are in the outside of the flywheel? I know the trigger coils sets the timing and syncronises which coil to fire to the switch blocks. I am just trying to find out if a single faulty stator coil could be responsible for a single cylinder failure or not. Cranking stater voltages mesured with a lab scope varied from 180-120 volts on the low speed and 30 on the high.
I had no spark cranking on 4-5-6 but good on 1-2-3. Trigger voltages were good mesured with a lab scope you could see a nice spike to 4 volts for each connection at the switch blocks. I replaced both blocks with CDI units and have spark cranking on all cylinders now but it still wont idle or start good. Before the blocks it was almost impossible to start now it will start after trying about 4 or 5 times of cranking but runs rough at idle to about 2000 RPM. After that she rocks out and will do 55 mph easy. I took all the carbs apart and replaced the gaskets, The floats were good and the bowls were all clean. I am running of of scratch and need to get her fixed before the season is totally over (only been out 1 time).

 

[Laddies]

Re: 1981 225 Black Max stator Questions

The stator has 4 windings for ign. 2 winding to a side (red&blue on 1 side and r/white&b/white on the other) 1 set of windindings supplies power for odd numbered cyls. the other even numbered cyls

 

[TheOzzieMechanic]

Re: 1981 225 Black Max stator Questions

Have CRO will measure. Here are some measurements for you at idle readings are as follow ( Peak volts not rms!!!) coils 90-145 (earth to coil -ve probe to coil +ve) Stator Low speed (blue wire on switch box to probe and engine to gnd lead) 180-265 @ idle and 195-345 @ 1000-3000rpm. Stator High speed ( red wire on switch box to probe and engine to gnd lead) 25-50 @idle and 120-320 @ 1000-3000rpm. Resistace check are as follows blue to red 3k5-4k2 blue/white to red/white as above red to gnd 90R-140R and red/wite to gnd same as red to gnd. Hope this helps

 

[rblanc9000]

Re: 1981 225 Black Max stator Questions

Thanks for the info, Am I understanding correctly that all the high speed coils have 2 windings in them and all the low speed coils have 2 windings in them.
Hence the 4 wires to the switchblocks. Are all the coils wired in series with the coils in there group or are they wired in parrellel to each other in the group? Is the AC current supplied to the swichblocks reasonably constant and the switchblock rectifies it and just taps into it when needed to fire a coil or do the coils produce a current that is rectified and stored in the switchblock for a specific cylinder and then completely discharged into the coil to fire it. I sorry to be such a pain in the a** but this system is new to me and everyone seams to know how to test it but I cant get a informitive complete answer to the theroy behind it. The Seloc manual I think im going to use for TP since they tell you enough information to get in trouble but not enough to get out- never said anything about dynamic stator testing with a volt meter. My local dealer has been helpfull but they wont work on my my boat because its overpowered. Ive been a Master automotive tech for 27 years Maby I should just stick a Focus engine on top of it and tape the Mercury covers on the sides.

 

[fishingdan]

Re: 1981 225 Black Max stator Questions

The flywheel spinning around the stator is effectively an alternator (produces AC current). Actually, it is an alternator.

 

[TheOzzieMechanic]

Re: 1981 225 Black Max stator Questions

There are four coils 2 high and 2 low one side (high and low) in series and the other side (high and low) in series. From a common gnd ( the engine being earth or negative) a coil with a low amount of turns called the high stator Produces a large Voltage at higher RPM. The output of the high stator is conected to the base of the low stator with the o/p being the blue or blue/white wire . The more turns the greater the voltage at low rpm. So effectively the two coils are series connected. They are then fed into the switchbox that then rectifies the voltage using a fulwave rectfier bridge. This voltage is then stored in a capacitor until a scr or transistor switch is triggerd using the voltage developed from the trigger coils to dicharge the voltage into an single coil (relevent to the trigger coil and voltage polarity). As the voltage in the coil primary winding decrease the magnetic field also collapses causing a step up voltage to be induced into the secondary winding of the coil. I hope this helps but it is probable as clear as mud!!!

 

[CharlieB]

Re: 1981 225 Black Max stator Questions

The major problem with an automotive background is to remember that this is just an oversized weedwacker, I mean 2-stroke.

They like fuel, to start, and idle.

Cold start, choke til it pops or fires then fast idle til it builds a little heat in it and smoothes out.

With no accelerator pump the idle has to be just fat enough as to allow for acceleration, and NO MORE.

Adjust idle mix to best idle THEN ADD an 8th turn at a time until the accel bog clears.

If no idle mixture screws on your carb, then it is time for a complete cleaning as the fixed idle jets and the fixed air bleeds may be dirty.

Done

 

[Laddies]

Re: 1981 225 Black Max stator Questions

rblanc, this isn't a weedwacker question that your asking but then what do I know? I knew where there was a engineering schematic for a 6 cyl ADI ign. I just could not remember which file I had put it in and have not had the time the last couple days to find it, hope it answers your questions if not get back and I will try to help you not change the subject

 

[rblanc9000]

Re: 1981 225 Black Max stator Questions

Awesome Laddies, and a thank you shout out to TheOzzieMechanic for the explenation to go along with the diagram. I love diagrams that are complete. My wiring diagram in the Seloc manual just has 6 wires that funnel down all the magic that is produced in the stator. Altho the diagram is complete outside the stator, they feel you dont have to know how the stator is internally wired. My problem is I want to know how it works and not just what I have to do to make it work. This diagram will help a lot an as soon as I figure out how to print it I will store it in a folder of stuff not in the manual. Cool, Its a picture file I just right clicked and saved it. Looking at the diagram it looks like the stator could not be responsible for a single cylinder failure since the AC wiring is common to all of the cylinders on each switch block and it looks like the rectified voltage is just stored for the next coil to fire not for any one specific coil, am I close? Fortunatly in my mild climate you can still go out with a sweatshirt on to almost November
Thanks again, Roger

 

[rblanc9000]

Re: 1981 225 Black Max stator Questions

Hey as long as I'm bending ears here, how often do the seals on the crank go bad? Are they extreamly difficult to replace? Do you have to remove the powerhead to axcess the block side ones or can you spin them around the crankshaft? Seams to me if a seal between 2 cylinders was leaking that would cause cross venting between the crankcases and cause a rough idle.
Running at high speed a small leak that caused a rough idle might not be noticable, Possible??? Is there any way to check them to see if there bad like a cylinder leak test or is that impossible because the exaust port will be open first. Or how about a leak check from the carburator side of each runner with the carbs off, piston at top dead center, the chamber should be sealed then right???
Thanks, Roger

 

[Laddies]

Re: 1981 225 Black Max stator Questions

Roger, the only things that can keep 1 cyl. from firing, a bad switch box, coil or wiring between the box and plug and of course the plug. As far as crank seals to get to the bottom one you must remove the powerhead. A main seal usually show up at idle, Take induction tach or meter and hook it to 1 plug wire at time and run the engine to see if it is spark or not

 

[j_martin]

Re: 1981 225 Black Max stator Questions

If you have good spark, idle problems are most likely either dirty carbs (the idle circuits are pretty fine) or faulty reeds. Either can show up at idle, and run fine at WOT. You've serviced the carbs, and if you took a look at all the little fine pinhole thingies under the plate on top (idle fuel insertion behind the throttle plate) they're good. There just ain't much to go wrong with them.

Try spraying a mist of water around the base of the carbs, and around the edge of the reed plate while it's idling as best as you can on the muffs. Might show up a bad gasket.

Has this engine ever run for you, or are you taking over someone else's problems? Been there, done that.

Another thought, bleed lines, and the check valves under them can have a gross effect on idle. If they're not right, they could cause other engine damage as well. Best to check them out. I've seen totally screwed up bleed line routing because there are several ways they route, depending on the engine.

We've all assumed that the basics have been done, compression test and link n sync.

hope it helps.
John

 

[rblanc9000]

Re: 1981 225 Black Max stator Questions

Thanks for the info Laddies and J Martin, to answer your question when I bought it last year in june it was always hard to start but you could get it to start after a few tries. It never had idled very good but usually idles just good enough to not stall. At the end of the season last year it became very difficult to start and the last time i took out it took both the batteries to get it started as the main one went dead from the cranking. After it started it ran okay the entire time at cruse and since I was in the bay I never shut it off till I got cold and decided to go home (2 hours). This year I checked the ignition and it would only fire a HEI spark checker (about 40,000 volts) on cylinders 1-2-3 and 4-5-6 were dead. After replacing both switch blocks it has spark on all cylinders now and seams to be back to the point it was when I got it. The idle is still so rough it shakes the steering wheel. It starts like only one cylinder is firing at first and it keeps throwing out the starter each time it pops. Once you get it started it usually will run for about 15 seconds before it stalls. If you restart it it usually will keep running after 2 or 3 stalls but it smokes bad at first like its flooded and is clearing out. I figgured a carb problems so I took them apart one at a time and they were very cleen inside. I checked the floats by filling the bowls with fuel and did not see any problems with them as well. All the little holes you described under the top plates were clear and I blew them out with compressed air just to make shure. I adjusted the floats, checked all the jets and replaced all the gaskets. I then replaced all the fuel lines and the big hoses on the sides of the engine as one was split where it contacts the barb of the fitting. I thought the enrichment circuit maby but the top carb was full of fuel when I took it off ( has the system that dribbles fuel into the bottom 2 carbs from the float bowl of the top one). When it was runnung I turned the screw on the enrichment solonoid and it started running rich turning it back it returned to normal bad idle. I think I will try running it with the hose pinched off just to make shure its not leaking down. The only thing I know for shure is cylinder #6 is good as it usually stalls when you take the plug wire off to check cylinder balance, the others dont seam to make as much of a difference when the plug wires are removed. Im going to check the bleed hoses tomarrow but it only looks like one was replaced for some reason maby a hole from wear on the throttle shafts. Thanks, Roger

 

[j_martin]

Re: 1981 225 Black Max stator Questions

I'd do a compression check. If that's good, check the bleed hose routing and also test the check valves on the bleed hoses. Try the water spray trick looking for bad gaskets. If that's all good, it's time to pull the reed block and check the reeds.

Keep us posted


hope it helps
John

 

[rblanc9000]

Re: 1981 225 Black Max stator Questions

Thanks John, Im going to take it out Sunday and we will see how it runs in the water with the new switch blocks. Im goingto do a compression test tomarrow and maby that will shed some light on the situation. Thanks, Roger