K11 Owners Group

atlantaboblutz@live.com

Since replacing the original BOSCH 75a starter relay twice due to occasional sticking contacts, I started to look for something different. Yes, I have read all the posts about sticking relays being an early sign of low battery voltage, but with a new battery and in the middle of a trip, I began to suspect that the new Tyco/Bosch relays may not have the quality of the originals.

I have not torn apart the relays to confirm... but for the relay to be so sensitive to voltage ... even on a brand new battery that tests perfectly ... didn't make sense.

So, I heard of the PAC 80/150amp battery isolator and decided to try one. Image is attached. First thing I noticed were the copper terminals for the battery hook ups. In the photo, I've already started the process to wire in. I made some connectors that plug into the existing plug from the ignition switch. Also confirmed that pressing the ignition button closes the relay (easily confirm with a multi-meter). I therefore know it will activate the starter before every starting the installation process. By retaining the original connector, I can always go back to the original relay style...and carry a spare with me.

The "real estate" inside the relay box is limited, so finding a good mounting place is the next challenge.

If anyone is interested, I will post my experience with this. BTW, this more robust relay is also less expensive. [img]https://plus.google.com/101025795667644355439/posts/cfP6LRUYhs3[/img]
_________________
Thanks,
Bob
Atlanta GA

'94 K1100 LT
'76 R75/6

nickw · Posted: Fri May 30, 2014 7:16 pm Post subject: Starter relay

Very interested in your project, please post for all to see.

I have always felt that the E-1 who specified the 75 A rating for the starter relay didn't understand in-rushcurrents in high load inductive devices. I have been watching mine like a hawk, prepared to disconnect at the first sign of welded contacts, keeping the battery at top condition,et.c. Perhaps the DIN ratings are done differently than SAE ratings, but 75A is easy to reach with a DC motor at low cranking speeds and near locked-rotor conditions.
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"It's not what people know, it's that they know so much that just ain't so!" (Apologies to Will Rogers)
93 K1100LT
(2) 79 Suzuki GS850's (In limbo)
65 Triumph TR6S/C ( sold)
2009 Suzuki SV650
2009 Suzuki DL650

Flying Duck · Posted: Fri May 30, 2014 8:03 pm Post subject:

I've messed with a lot of K bikes and only seen a starter relay go bad once. That was on a 100K parts K75 that I bought from a guy who tried to start it with a very low battery and did the old weld the contacts together bit.
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93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
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atlantaboblutz@live.com · Posted: Sat May 31, 2014 10:27 pm Post subject: Success

I agree w/Drake that the originals were solid. Only through a sticky problem did I need to replace it. My observations are limited only to new relays

Well it took some engineering with connectors relay placement, etc but the PAC 80 is in and fired perfectly first time. We'll see how it goes. Looks promising ...can handle 150amp bursts / 80amp continuous.
_________________
Thanks,
Bob
Atlanta GA

'94 K1100 LT
'76 R75/6

atlantaboblutz@live.com · Posted: Mon Jun 09, 2014 3:35 pm Post subject:

Well, after a number of rides including very short jaunts... there have been zero problems with the new relay. If you're curious, here is how the two look side to side

All connections were soldered except that the "signal" wires plug into the existing connector. In that way, I can always go back to a standard relay. The pic was taken when I was still in "desk checking" mode.

The temp connectors shown in the photo (to the battery and to the starter) were replaced with heavier connections appropriate for battery amperage. If one has the energy (and I might as a winter project), you could put an in-line 100amp fuse leading to the starter.

The relay is in the fuse box under the seat with the bottom on the back side of the box and posts facing the middle of the box. I'd post a pic but am a bit busy to go out and take the darn tank off again.
_________________
Thanks,
Bob
Atlanta GA

'94 K1100 LT
'76 R75/6