EFI motor to a carb motor

[dvjoiner]

I have a 1985 EFI motor that I am putting in a 1987 carb bike. I am taking the EFI unit of the 85 motor and putting the carbs off the 87 motor on it to put in my 1987 bike.
I know that I have to change the pulse generators ,oil sending unit can I take off the camshaft angle sensor off and put cap off the 87 motor on and what other stuff do I need to change

 

[slabghost]

Hold off until you get a full answer some of that stuff may be just fine to use. Steve83 should be along soon. He did the reverse and put fi on a carb motor.

 

[joedrum]

well it shouldnt be to much a hassle ...i would do as little as possible till it will run ...my plan would be to use the stuff on bike to use as it is what wired up on bike ......seems you are looking at the approach fine ...good luck ..im am sure you will get it done

 

[tuna boy]

Just an EFI vs carb question. I thought that the efi bikes were better and did not require all the fiddleing that the carb bikes need? I am amazed at the things that some of the members here can do with the 4 cylinder Wings. Way past what I would tackle.

 

[joedrum]

lack of parts and support by honda ...makes FI on 1200s hard to maintain ...

 

[mcgovern61]

joedrum » Sat Jan 17, 2015 8:39 am[/url]":12re5i0f]
lack of parts and support by honda ...makes FI on 1200s hard to maintain ...

+1 :yes: Those EFI parts are hard to come by and expensive when found.

 

[dvjoiner]

mcgovern61 » Sat Jan 17, 2015 12:58 pm[/url]":3grlhts1]

joedrum » Sat Jan 17, 2015 8:39 am[/url]":3grlhts1]
lack of parts and support by honda ...makes FI on 1200s hard to maintain ...

+1 :yes: Those EFI parts are hard to come by and expensive when found.

Then I might make a few $$$ I have a complete EFI unit less comp. & wiring that will be up for sell after I take it off the motor

 

[Steve83]

You can cap the cam sensors - not needed. The EFI has only 1 crank sensor, carb'd has 2. The coolant lines for the air valve (one at the water pump, the other at the thermostat housing) will need to be connected together - the EFI engine has no internal coolant bypass. The oil pressure switch will need to be moved to the top of the engine, or the wire lengthened. The oil temp and pressure senders can be removed and the ports plugged, or just leave them in place. The timing mark cover has a vent tube that goes to the oil pressure sender - use the standard cover. I believe everything else is identical between the 2 engines. If I think of anything else, I'll post it.

 

[ekvh]

The coolant lines for the air valve (one at the water pump, the other at the thermostat housing) will need to be connected together - the EFI engine has no internal coolant bypass. --- Wow, can you elaborate on that? That would make the two blocks significantly different from each other. I have an 87. I have an 85 water pump cover and thought I could use it for additional heat placement.

 

[Steve83]

The 1200 EFI case is not drilled for a coolant bypass. The coolant is routed through an air valve, which allows more air into the intakes to speed up the idle when cold. The coolant warms, the air valve closes, and the idle is slowed down to normal.

This would be a perfect heat source for a single carb setup.

In order to use an EFI thermostat housing with it's 2 extra ports (coolant temp sensor and air valve outlet), the stub at the front top center of the case must be cut off. It would probably be easier to tap a nipple into the original thermostat housing.

EFI water pump cover with coolant inlet:

1200 CFI Water Pump Cover

• Steve83
• Nov 2, 2013

EFI thermostat housing with coolant outlet:

1200 Thermostat Housing

• Steve83
• Nov 2, 2013

 

[joedrum]

hmmmm...

 

[ekvh]

This maybe should go in a new thread, but apparently the 1200's had different circulatory path than the earlier years. The EFI models had an exterior bypass as Steve83 has shown. How did the other 1200's do this? I can't find info in the manuals. Throwing it out there to anyone who knows.
75-83 had this return on the bottom side at about 12:00 in pic:

85efi had a return line on the outside seen here at around 6:00

85 non efi had the bottom port plugged

For some reason here's an 83 1100.
Did the other 1200's just spin the pump until the thermostat opened? Forgive my usual ignorance, just trying to know the differences. I assumed they were the same.

 

[ekvh]

Should have included this from a 1000.

 

[dvjoiner]

Look's like what I though I had to do, I had to, Take off everything off old carb motor and put on EFI motor

 

[dan filipi]

Far as I could tell, the 1200's with no bypass relied on the hole in the thermostat to allow flow.