1980 CM400 engine swap/wiring help

Hello all!

I'm new to this so bear with me...

I have a 1980 Honda CM400T. While driving on the highway, a gasket blew and I lost all of my oil and the transmission seized. My more mechanically-minded friend recommended that it might just be easier for me (at my beginning-level of bike maintainer/tinkerer) to swap out the engine with one from a similar make/model rather than rebuilding the lower portion of the engine.
So...
I found a 1980 CM400A engine with <10K on it. I swapped it out, plugged it in (all the connectors fit perfectly) and tried to start it up...
Well, the starter turns and I have compression, but no spark. My mechanical buddy tells me that the signal from the alternator providing timing to the spark plugs is not happening.

Please help this noob with a voltmeter and an extremely basic knowledge of electrical systems and a broken brat bike.

Thank you!

-HoldFast

Here is the wiring diagram I found for the 400A (top one) and the T (bottom one)

Talked to the Honda motorcycle dealership today. Looks like I will need a new CDI. Will I need to install a kickstand switch and changing relay though? Or can that be bypassed? Does anybody know if a CDI from a CB400a would work on this bike?

Sorry - lots of questions...

CDI from the CM400 and CM450 are the same, as is the CB400T and (I think?) the 450 Nighthawk. There's a guy on eBay who sells replacement boxes for a reasonable price, too.

http://www.ebay.com/itm/192182173867

Clutch and sidestand safety switches can both be bypassed easily. Locate the green/red wire coming from the solenoid and run it directly to ground.

" data-source="" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch">

Sonreir said:

CDI from the CM400 and CM450 are the same, as is the CB400T and (I think?) the 450 Nighthawk. There's a guy on eBay who sells replacement boxes for a reasonable price, too.

http://www.ebay.com/itm/192182173867

Clutch and sidestand safety switches can both be bypassed easily. Locate the green/red wire coming from the solenoid and run it directly to ground.

Click to expand...

Thanks Sonreir! I appreciate the help. I asked around the HondaTwins site and a few guys there suggested that I swap out the rotor/stator and see how that goes. What's your thoughts on that?
Thank you again for your help!!!


Sent from my iPhone using DO THE TON

HoldFastHope said:

Thanks Sonreir! I appreciate the help. I asked around the HondaTwins site and a few guys there suggested that I swap out the rotor/stator and see how that goes. What's your thoughts on that?
Thank you again for your help!!!


Sent from my iPhone using DO THE TON

Click to expand...

If the CDI isn't the problem, then it's probably the stator. Good luck finding one, though. :-\

It's a common part to fail. A company called RM Stator was refurbishing them for a while, though I seem to recall they stopped doing that.