Page 1 of 1

Starter Relays

Posted: Fri Feb 03, 2012 9:12 am
by 05hexhead
I have the Valero starter out of my '95 completely torn apart for overhaul, because it never cranked as fast as the Bosch in the '84 even after swapping batteries. The back end dismantle is a real pain on the Valero and other parts don't seem that robust compared to the Bosch.

I am seriously thinking of swapping starters and putting the Bosch in my '95 as it is my favorite and long term bike. I have never had any problems with the other Bosch starters that I have had over the years, and the PO had already replaced the Valero in my '95 at some time.

Just to get this right I should have the starter relays follow along if I do the swap?

Re: Starter Relays

Posted: Fri Feb 03, 2012 1:27 pm
by the quinner
You should be fine...the Valeo required the somewhat more robust relay. The only issue I know of is retrofitting the Valeo to the mid-80s bikes (85, 86, 87, 88...)...those bikes had starter relays with diodes that were not up to the draw of the Valeo solenoid. Overall, the Valeo uses less current than the Bosch...the solenoid of the Valeo uses MORE than the Bosch, though.

Re: Starter Relays

Posted: Sat Feb 04, 2012 9:25 am
by 05hexhead
Thanks.

The twin shock early 80's relay that I have, is similar to the mono shock?

Re: Starter Relays

Posted: Mon Feb 06, 2012 12:39 pm
by the quinner
05hexhead wrote:Thanks.

The twin shock early 80's relay that I have, is similar to the mono shock?
Not really. Yes, they are both relays and all relays have similarities...but, in your specific case, the way they work and interact with the other circuits is different.

The early 80s relay will have two "87" terminals...the clutch/neutral safety diode will be behind the circuit board in the headlight bucket...

The 85+ starter relays have the safety diode built into the relay. The original version of the relay with the diode was not robust enough for the Valeo solenoid, so it was updated. The updated version is all that is available through BMW (IOW, it's good for the Bosch or Valeo starters).

The terminal locations also changed.