CDI different ignition-curves

[Habbeli]

Can I install a CDI from an LTD without changing the flywheel / ignition plate / coil 

[Trucker]

Can I install a CDI from an LTD without changing the flywheel / ignition plate / coil 

yes

[Habbeli]

Thanks for the reply Trucker  ,  then I just have to start looking for a CDI from a newer LTD   
By the way, what should it be called? There's partnumbers but the CDI is labeled with something completely different ....

[gixxer6]

Can I install a CDI from an LTD without changing the flywheel / ignition plate / coil 

yes

Trucker, Have you done this? 

[Trucker]

I swapped a few around there was no seat of the pants change to it.

[Checkmarks]

Well, I just got to the bottom of some more cdi work.  My 4/6 motor has one of those square like cdi's as opposed to a more rectangular cdi.  It looks more like an aftermarket but then it hooks up jut like any other Ltd cdi.

The point of doing this work was to see what is up with my motor.  It has an issue with revving up.  The motor will bog when the throttle is first put to WOT and then a moment or two later the motor screams up to the 8k's.  When the throttle is let off and then re-applied to WOT the motor will continue to bog down to 5300 rpm and then scream back up to the 8k's.  Additionally the motor hesitates around 5300 for a moment when WOT from 3k.  Something is up and I cannot quite put my finger on the problem.

I put some timing marks on the clutch or at least a TDC to verify the retarding action.  Getting overly detailed is pointless if you just want to see the retarding in action.  Seems this CDI box does what a standard Invader ignition does.  That is right, it looks like the timing only progresses to 10 to 12 BTDC.  This is nothing like the Ltd cdi. 

So I try putting a known true Ltd cdi on the motor and it would not even start.  It was like the timing was WAY to advanced.  Sometimes when trying to start there were backfires out the exhaust.  Other times it was backfiring out the carburetors.  In the end putting on the 81-82 Ltd cdi did not work.

My next try will be replacing the stator assemblage. 

[Habbeli]

What happened with this?

[Habbeli]

Bump 

[sprocket]

Interesting I ran my race engines to 9800 Rpms now on a dyno reading I never got a reading out of the timing curve everything else though. The one engine ran @ 9350 Rpms with 90hp, the 9800rpms over 100hp. The timing curve is a fixed 15 degrees on stock, there is a company offering Msd but the price is expensive there you can change all your settings

[Habbeli]

Guys,,, we never got to the end of this thread.
Checkmarks, how did it go with your engine?
I really want to try a different ignition curve CDI so the question is, can I safely mount a cdi from a -82 LTD and not have to replace the flywheel and ignition plate?  I hope so     

[Checkmarks]

Hab,

I am in the process of welding up a new pipe and slapping on some 4/6 cylinders.  When I finish the pipe I will get to the answer.  Suspect bolting on the mono cdi still works.  Likely one week out to complete for me.

Standard round head lower unit with 4/6 cylinders/heads.  It will be a good valid test to see if just slapping on the cdi results in anything positive.

[Habbeli]

Hab,

I am in the process of welding up a new pipe and slapping on some 4/6 cylinders.  When I finish the pipe I will get to the answer.  Suspect bolting on the mono cdi still works.  Likely one week out to complete for me.

Standard round head lower unit with 4/6 cylinders/heads.  It will be a good valid test to see if just slapping on the cdi results in anything positive.

That sounds great, hope it goes well with the pipe 

[Habbeli]

Checkmarks,,  how is it going for you? 

[Checkmarks]

Well, the pipe must be welded up by now!  The 4/6 cylinders are on the sled (IFS required a custom pipe) and that sled runs great.  I tried to look up information in my filing drawers and no luck there.  Let this be a lesson to make better notes.  Lately I have been tied up pulling fish from ice holes and modifying the fishing shelter.

Ice ovals in a couple of weeks.  The racing will get me spurred into action.

[Habbeli]

Bryan is right.  Points measured and then excel plots, graphs and makes a file.  Then this forum does not afford for excel attachments so then the online converter makes it look like you see divided on two pages.

As far as hot and cold Mark, that was learned through experimentation.  The numbers moved while while verifying my data.

You are welcomed to my excel sheet just leave you e-mail Hab.

did you get my email address?