The 550 Ignition interchange project continues.

[Guest]

Well I got the first of my project igniters and signal generators (off an 83, 750) from friend SVsooke this week (thanks man) and had a little time to play with it tonight. A quick check of my wiring diagrams and it appears the pinouts are the same on the output side so no worries of trying to figure that out So check number one.

The trigger rotor fits and the side cover will go back on without fouling anything, so check number two.

Now it gets interesting. The signal generator plate from the 550 is roughly 80mm in diameter but the 750's plate is 84mm so it won't just drop in. Drat. There are 4 locator posts that hold the plate in position and in alignment with the trigger rotor. They are notched so it seems that the either they will have to be removed or the plate will need to be notched to fit. Problem number one. To work on the plate you need to remove the pickup coils however the 4 screws that hold them seem to have been put in with an airwrench and they don't budge. I'm afraid to use an impact wrench on them as I may shatter the magnets in the coils so that's out. Making it more difficult, the screw heads are slotted and the darn slots are several mm wide. Wider than standard screw drivers. I don't have one that fits and nothing that I can fabricate to the correct size. I'll see if I can pickup a larger driver tomorrow.

Well that's as far as I got tonight but it definitely seems doable. If I can get the right size screw driver to get the pickup coils off I'll have a better idea of how to make the plate fit. I could possibly move the coils to the stock plate but I think the easier method would be to modify the larger plate. Maybe not but I'll try that first.

Stay tuned. I'll take pics as I go and if it works out I'll write a guide.

I am planning on getting the plate mounted on the weekend so it shouldn't be long before if I know it works. Keep your fingers crossed please.

Cheers all,
Spyug

[JEEPRUSTY]

Ohh my this is timely.
You mean the screws that are holding the signal generator on the bike?
They are a bugger but one coming off would be nasty.

The magnets actully just get sandwiched under the coils no idea why.

You do have a 550 igniter don't you?

[blowerbike]

Well I got the first of my project igniters and signal generators (off an 83, 750) from friend SVsooke this week (thanks man) and had a little time to play with it tonight. A quick check of my wiring diagrams and it appears the pinouts are the same on the output side so no worries of trying to figure that out So check number one.

The trigger rotor fits and the side cover will go back on without fouling anything, so check number two.

Now it gets interesting. The signal generator plate from the 550 is roughly 80mm in diameter but the 750's plate is 84mm so it won't just drop in. Drat. There are 4 locator posts that hold the plate in position and in alignment with the trigger rotor. They are notched so it seems that the either they will have to be removed or the plate will need to be notched to fit. Problem number one. To work on the plate you need to remove the pickup coils however the 4 screws that hold them seem to have been put in with an airwrench and they don't budge. I'm afraid to use an impact wrench on them as I may shatter the magnets in the coils so that's out. Making it more difficult, the screw heads are slotted and the darn slots are several mm wide. Wider than standard screw drivers. I don't have one that fits and nothing that I can fabricate to the correct size. I'll see if I can pickup a larger driver tomorrow.

Well that's as far as I got tonight but it definitely seems doable. If I can get the right size screw driver to get the pickup coils off I'll have a better idea of how to make the plate fit. I could possibly move the coils to the stock plate but I think the easier method would be to modify the larger plate. Maybe not but I'll try that first.

Stay tuned. I'll take pics as I go and if it works out I'll write a guide.

I am planning on getting the plate mounted on the weekend so it shouldn't be long before if I know it works. Keep your fingers crossed please.

Cheers all,
Spyug

i commented several times on the ignition plate diameter being the big problem.
also...
the 750 box plugs into the 550 but will not work.
i tried all of the above over a dozen years ago.

there is a work around but it involves moving the larger trigger plate towards the outside of the case halves.(dynaS).
it doesn't hurt to keep trying though.
keep us posted.

[JEEPRUSTY]

Now that I recall I actually bent my slotted impact driver bit taking one off my 550.
sent one coil to a guy in nevada is he still here? Anyway thats how I found out about the magnets sandwich thing.

If you fear damaging the coils then take them off the plate they come off very easily.

[koolaid_kid]

AFA finding a slotted screwdriver to fit, all you need is a sacrificial screwdriver and a bench grinder (or equivalent). Just grind it down until it fits snugly in the slot. Won't be much use for any other screw, but it was sacrificial to begin with.

[spyug]

You do have a 550 igniter don't you?

Yes I do but its kaput. They are harder than hens teeth to find used thus my little quest for an alternative.

the 750 box plugs into the 550 but will not work.
i tried all of the above over a dozen years ago.

I wonder if you can elaborate for me. I realise the 750 igniter will plug in but its not compatable with the stock signal generator thus my thoughts to use its own generator. The plug outs on both igniters are the same so as long as the signal gets from the pick up coils to the igniter, the igniter should trigger the coils. Now the ignition advance curve built into the igniter will not be the same, I realize, but I'm betting it will be close enough. I'd be interested in learning where my logic fails.

AFA finding a slotted screwdriver to fit, all you need is a sacrificial screwdriver and a bench grinder (or equivalent). Just grind it down until it fits snugly in the slot. Won't be much use for any other screw, but it was sacrificial to begin with.

Thanks I realize that but I presently don't have a driver that is remotely thick enough to fabricate to the right thickness. I'll see what I can pickup tomorrow.

The fun will continue.

cheers all,
Spyug

[blowerbike]

same connectors on a 83 750 and all 1150 boxes.
all of the above will plug and play with each other.
advance curve means nothing right now as the above boxes will plug into the 550 but not make any sparkles.
why...i didn't go any further years ago but i tried this on 2 different 83-86 550's.
i did try to install a 750 plate and seen it was way to large in diameter to fit the cases.
i assumed it was the igniter...both bikes had around 2k miles and was like brand new.
hell i have no clue why they wouldn't work besides the part number being totally different.
i'm sure those 2 bikes ended up in a barn somewhere(circa 1990).
i had also mentioned the plate diameter being an issue on one of your other threads..i gave you the measurement for a normal GS plate so you could compare to the smaller version 83-86 550's.

[SVSooke]

I had a time getting those screws off the 750 engine to.

[spyug]

Progress report

I did manage to get the pickup coils off the plate using a modified screwdriver but as I feared I cracked both the magnets. Once I had them off I was able to rework the plate so it fit the case.I assembled everything but have been unable to get spark.

I double checked that the igniter is working by plugging it into my 750. I also checked the resistance of the pickups and they are in spec but no spark.

One thing that I found a little confusing with the signal generator is a yellow/green wire with a spade connector that fits to one of the plate fixture screws on that end and has abullet connector on the other end that plugs into the harness. I take it to be a ground although its not shown on the wiring diagram. There is no connector for it on the 550 wiring harness so I attached it directly to the battery negative terminal.

Could anyone please confirm that it is indeed a ground?

Household chores kept me away from delving deeper today but I hope to get back on it tomorrow.

Cheers all,
Spyug

[JEEPRUSTY]

I did manage to get the pickup coils off the plate using a modified screwdriver but as I feared I cracked both the magnets. Once I had them off I was able to rework the plate so it fit the case.I assembled everything but have been unable to get spark.

I double checked that the igniter is working by plugging it into my 750. I also checked the resistance of the pickups and they are in spec but no spark.

One thing that I found a little confusing with the signal generator is a yellow/green wire with a spade connector that fits to one of the plate fixture screws on that end and has abullet connector on the other end that plugs into the harness. I take it to be a ground although its not shown on the wiring diagram. There is no connector for it on the 550 wiring harness so I attached it directly to the battery negative terminal.

Could anyone please confirm that it is indeed a ground?

Household chores kept me away from delving deeper today but I hope to get back on it tomorrow.

Cheers all,
Spyug

could that have been a feed to an electronic tach?

[spyug]

could that have been a feed to an electronic tach?

I can't see how that would be but I'll look at the wiring diagram again and see what it shows. It was definitely fixed to one of the plate screws so no where near the crankshaft.

Thanks for the suggestion.

Spyug