78 1000 becoming a 78/85 1200

[70sbudget]

So it’s an 85 according to the numbers. No carbs included and that’s okay with me as I was looking to convert to single carb anyway.

Pics of the motor are on the first page of the thread.
I don’t see any indication of a heat plenum on the front. Any keen eyes out there able to tell if it was efi or not? Where did the electric fuel pumps get mounted?

[ericheath]

It doesn’t appear on page 1 to have the auxiliary port. So it is likely a carbureted model.

[70sbudget]

It doesn’t appear on page 1 to have the auxiliary port. So it is likely a carbureted model.

Was the tach electric? I know the clutch was hydraulic but where was the pickup for the tach?

[pidjones]

The high pressure electric fuel pump was mounted rear right side of the motor. I seem to remember a pickup off the crank in the area of the timing belts. Try looking at one of the online parts diagrams on Southern Honda. https://parts.southernhonda.com/Honda_1 ... ngine.html

[Shadowjack]

1200s have electric tachs.

[ericheath]

Almost any electronic tach from the era will work. Mine’s from an 85 Magna. Just tap into a coil wire for pulse. Probably should be from a four cylinder waste spark bike???

The pulse generators and pickups are behind the belt covers on the crank. To use it, you will need a “black box” ignition unit and appropriate coils. (3.0 ohm or more) Lots use 1500 coils. The 1200’s use a vacuum signal and gear indicator to determine timing. I believe gears 1-2-3 were set, but 4-5 could vary the timing based on vacuum. It was capable of quite a bit more advanced timing than earlier years.

Advice I have read on black box was to find a green label box. The black label ones are said to be more prone to failure.

Wondering what you got yourself into?? LOL Don’t be, you’ll get there and be happy when you ride it.

Collecting parts can nickel and dime you. The other option is fly-cut the pistons and swap 75-79 heads on and use the 1000 ignition. Work and cost of head gaskets.

I mounted Power Arc off the front crank. However, unless you’re a machinist, it’s not easy and sets you back $400 or more.

[70sbudget]

Guessing I’ll have to do some frame cutting too! This green box or black box..... where can these be found?

[70sbudget]

Besides the above posted question about the black and green boxes, now that I have a 1200 that’s to big for the 1000 frame and the rear covers have to come off of both to switch the drive output shaft.......

Are the stators and rear covers interchangeable? This would possibly allow me to use the 1000 rear cover on the 1200 and save cutting the frame? There is the hydraulic clutch on the 1200 that may pose an issue

[wingrider]

Are you certain it won’t fit? They are not quite the same between the 1000, and the 1200

[70sbudget]

Are you certain it won’t fit? They are not quite the same between the 1000, and the 1200

99% sure as the stator is almost a full inch deeper on the 1200

[wingrider]

Have you tried to put it in the frame yet? May surprise you....take a look back on page 2...that is a 77 frame with an 84 block...

[70sbudget]

Current status 1978 1000

EC809A76-CCEB-4176-A874-2021975AEB62.jpeg (164.37 KiB) Viewed 147 times

Need a shoehorn for the 85 1200. Unknown carb or efi motor

0494B2DD-04F2-42F9-82AB-5997F9E682FE.jpeg (141.65 KiB) Viewed 147 times

[ericheath]

It will fit. I had to give some love to the frame a bit with a hammer where the stator is closest to the frame. It’s tight by the starter and the front covers are close.

[70sbudget]

It will fit. I had to give some love to the frame a bit with a hammer where the stator is closest to the frame. It’s tight by the starter and the front covers are close.

Your optimism is appreciated and encouraging! Where do I find these mysterious green and black boxes? Think I’ll look at doing the dodge neon coils due to cost.

I’ll be converting to single carb. Are the locations of the intake holes in exactly the same places motor to motor?

[ericheath]

Boxes are referred to by Honda as Ignition Control Units. eBay or a bike breaker. The green and black parts are labels on the boxes. The boxes are black plastic. Their prices are going up it seems as to my knowledge, no one is making a replacement yet.

2B951780-6459-488F-8948-A167988DB0F2.png (180.34 KiB) Viewed 132 times

And the fun part is hoping the one you get still works.

The only workaround the box is a C5, $$$, or different heads and the early ignition system.

On the Neon conversion; I’m no electrical expert, but Dyna and most electronic Honda bikes go with three ohm or higher coils. The 1100’s were an exception. They went low ohm without a ballast resistor in 80-81 and added the resistor in 82-83. The coil ohm changed also. The Neon coil is about 0.7 ohms. I know a few people who used them on 1000 bikes and reported here, had trouble with start buttons and maybe stop/run switches in the early going. I know a lot of people talk about doing it, but I haven’t read of any results long term. I believe Dave0430 did install a set on a 1200, or helped someone, and he did install a set on a 1000 with points but used the ballast resistor.

My understanding is that lower ohms allow higher amps. One person who put them on his 1000 without a resistor was seeing large sparks at the points. One poster figured there was 20 amps running through the points.

The Neon is a cheap route to go, but I think you should get the ohms up to 3.0 like stock 1200 coils.

Someone else who understands this better, please jump in.