Tach inop after COPs mod!!

[Ratt1eHead]

Here's what I have, 1997 Max, stock cdi, I used early 2000's r6 coils (mitsubishi). I did the rear COPs first, started the bike to make sure it all worked, and it runs fine. But I have no tach reading. Then I did the front two COPs, and still no tach reading. Any suggestions? Thanks.

 

[rollin thunder]

My tach hesitates when I start it cold so, I tap on it and the needle starts working.

 

[DMAN999]

I installed Gannon's (88vmx12) COPs kit and my tach works fine.
He does have inline resisters in his wiring harnesses, that may be what's causing your issue (lack of proper resistance)

 

[alorio1]

My COP kit came with Denso's from a SUZUKI
07 08 GSX-R1000 OEM PART # 33410-35F10
129700-4400 stamped on the top of each coil. All COP's do not have the same resistance, maybe you don't have enough resistance for the TCI to detect or just the opposite too much resistance.

 

[DMAN999]

My COP kit came with Denso's from a SUZUKI
07 08 GSX-R1000 OEM PART # 33410-35F10
129700-4400 stamped on the top of each coil. All COP's do not have the same resistance, maybe you don't have enough resistance for the TCI to detect or just the opposite too much resistance.

Mine too (they are 1.5 Ohm Coils) plus they have an inline resistor (in Gannon's Wiring Harness) also.
Here's a set for $30:
http://www.ebay.com/itm/GSXR-GSX-R-...Parts_Accessories&vxp=mtr&hash=item43bb2f5d1b

 

[Ratt1eHead]

Thanks DMan! I just ordered the denso's from ebay. I'll let you know if it cures the problem when they arrive. I'm guessing that the cdi sends the tach pulse from one of the rear two cylinders. I'll do one at a time and post the results.

 

[bazwell]

From memory the tacho pulse comes off the no. 1 coil, neg- side.

 

[wildweasel_pt]

Doesn't that depend on which year the bike is from? IIRC older bikes its #2 cylinder but im not sure

 

[Ratt1eHead]

Well, I only changed the rear two cylinders first, then started the bike, just to make sure things worked. That's when I noticed the tach was inop. Which leads me to believe the feed is from one of the rear cylinders.

 

[wildweasel_pt]

Yes. I think that post 89 the pickup is on the #1 cylinder as Baz noted but older bikes is #2 but i stand to be corrected.

 

[Bill Seward]

85 Max. Homemade COPS harness. Never had a problem with the tachometer - except for having to give it a whack now and then after starting to get it and the temp gauge to work...

 

[Ratt1eHead]

Fred, I gotta say.... I love your bikes!!! Very AWESOME! I'll have the denso COP's next week... hopefully I'll have some answers.

 

[Ratt1eHead]

Ok, here is the update... I got the denso sticks today. First I swapped out the left-rear, still no tach. Then I swapped out the right-rear, voila, that did the trick. So I'm guessing that the right rear is where the CDI unit pulls the signal to send to the tach, and the mitsubishi sticks are even less resistance than the denso's, so the signal was lost to the CDI unit. Thanks for the feedback guys!

Mark