TCI

I purchased a used TCI off a member of this site last year. I fried my old one from not disconnecting it during compression test. Lesson learned. My bike is a xj750 and the used one i got is from a xj650. I know the timing curve is not exactly the same but how big of a difference should i notice if any? I did not ride bike much last year but did seem like it was lacking some take off power from before. But not positive. Otherwise bike is running tip top shape.
Thanks, Dave

 

I didn't look up the specs for either of those TCI's but I bet all of them are about the same at low RPM's and advance from there.

There is usually a chart of advance amount vs RPM in the service manuals... Maybe you could pull copies of the two bikes and compare them?

 

HCP413
OEM TCI Ignitor Unit
oem # 4H7-82305-10-00
small black label lettered:
TYPE TID14-02
4H7-10 (date code)
4 + 4 terminals
Advance curve:
10* at 1050 rpms
12* at 1800 +/- 200 rpms
35.5* at 4100 +/- 400 rpms
37.5* +/- 2* at 5000 rpms

Applications:

1980-81 XJ650 M, MM





HCP7572
OEM TCI Ignitor Unit
oem # 5V2-82305-10-00
small green label lettered:
TYPE TID14-08
5V2-10 (date code)
4 + 5 terminals
Advance curve:

7* +/- 1* at 1050 rpm
9* at 1600 +/- 200 rpms
35.5* at 3300 +/- 300 rpms
37.5* +/- 2* at 4000+ rpms

Applications:

XJ650RJ and RJC Seca





HCP414
OEM TCI Ignitor Unit
oem # 5G2-82305-10-00
small red label lettered:
TYPE TID14-06
5G2-10 (date code)
4 + 5 terminals
Advance curve: (NOTE: something is suspect, it's the same curve as the 650RJ unit above.........)
7* +/- 1* at 1050 rpm
9* at 1600 +/- 200 rpms
35.5* at 3300 +/- 300 rpms
37.5* +/- 2* at 4000+ rpms

XJ750 Seca (factory manual):
7* at 1050 rpm
12* at 1800 +/- 200 rpms
35.5* at 4100 +/- 400 rpms
37.5* +/- 2* at 5000+ rpms

Applications:

XJ650 Police
1982-84 XJ650 Maxim
1981-83 XJ750 all models
XJ750 Police

 

Than you very much Len

 

So If I had a TCI unit off of a 1981 650 maxim on my 1982 would that make a significant difference?

 

Flatheadsix1949,

Using the 1981 unit has 3 more degrees at idle. It may idle a little smoother but it may be a little harder to start because you are lighting the mixture earlier as the piston is still coming up thus fighting the starter. The sympton, if you have it, would be like having a weak battery, slower cranking. I would try it.

 

So could it be be preventing the bike from not starting altogether/no spark?

 

Plug it in.
Fire that baby up.
You may actually LIKE how it runs.

An Ignitor that gets you out-in-traffic is all you need!

You got a "Road Bike"
Not a "Drag-Bike"

You're interested in how long it takes to go 75 ~ 100 miles at a steady Mid-range and WOT for passing.
You'll still get from light to light with the gang.
Plug it in and ride.
If you hate it, ... change it.

A 10-minute job.
Not how quick you can go a quarter-mile!!!

 

Yeah I was just wondering if it could prevent my bike from getting spark because as of now I'm not getting any and I was wondering if this could be an issue.

 

IF, ... it was runnin' OK before the TCI crapped the bed.

I'd suspect the Box.

Iffin' the IGN Circuit shows the juice is on.