955i Regulator / Rectifier Replacement and Relocation

[Stretch]

The four R's.

Like a few others here, I had a Regulator / Rectifier burn out on my 955i Tiger.  And in doing so, the R/R spiked the Stator, killing it as well.  A bit of digging around revealed that this problem is not exclusive to 955i Tigers.  Many other bikes experience R/R and subsequent Stator failures due to excessive heat buildup within the R/R itself.

The older SCR-type rectifiers and Shunt-type regulators (both found in the stock Triumph and aftermarket replacement parts) build up heat as a by-product of the part doing its job:  The Rectifier strips away half of the Alternating Current coming from the Stator, converting it into Direct Current.  The DC is then sent to the Regulator, where excess voltage is internally dumped to Ground, creating more heat inside the R/R.

And to top it all off, the R/R, which must remain cool in order to continue functioning, is tucked away between the battery box and the frame, with a panel of bodywork keeping the R/R out of sight.  So the only air the R/R gets is a small amount of hot air coming off the cylinders.

I believe that a possible solution is to move the R/R to a more suitable location, where it can get the cooling air it needs to function properly, and to replace the Triumph-type R/R with a modern, cooler-running MOSFET (Metal Oxide Semiconductor Field Effect Transistor) R/R.



Shindengen FH008EB Regulator / Rectifier from a 2008 Honda CBR1000RR ($40 used on eBay), mounted in place of the seat lock.


R/R bolted to a piece of 1/4-inch thick copper, with 14 computer heat-sinks (from Radio Shack) screwed to the back of the copper.  The copper plate draws heat away from the R/R, and the heat sinks draw heat from the copper plate.  Heat sink compound was used between each piece of metal to enhance the thermal conductivity between each part.


The body of the R/R is grounded directly to the Negative battery terminal, eliminating the possibility of a bad ground between the R/R, its bracket, the bike frame, the wiring harness, and the battery itself.  I grounded the R/R straight to the source.


Not bad at all from a distance.  Hell, only a Girly owner would notice something amiss.


All push-in connectors were cut off the wires, and each connection is soldered together, eliminating any conductivity problems due to faulty connectors.  I used a 30-amp Maxi fuse for my wiring harness bypass (Sasquatch Fix), eliminating the possibility of overheated connectors from too small of connections in an ATC fuse holder.

You wouldn't believe how much cooler the new setup runs.  After an hour's ride, the old setup would get the stock R/R so hot, you couldn't keep your hand on it.

This past Saturday, I put 200 miles on the bike, riding  state highways, Interstate, city traffic, and dirt roads.  At no point did the new R/R get too hot to touch.  In fact, it remained barely warm to my bare hand.  The black tank side-panels got hotter than the R/R.

Anywho, just posting my latest experiment.

[ackme]

interesting.  What are you doing to unlock your seat?

ack

[Stretch]

Pull on the end of the cable.  

[ackme]

That is an important step.   :)

I should have asked; where did you relocate the key lock for the rear section?

ack

[Stretch]

I haven't.  I just tug on the cable.  :mrgreen:

[ackme]

That is an important step.   :)

I should have asked; where did you relocate the key lock for the rear section?

ack

[Stretch]

I haven't.  I just tug on the cable.  :mrgreen:
















I'm getting bored already.

[ackme]

Don't know where that re-post came from.

I only ask because my 05 has one of these where it looks like you mounted your R/R

[Stretch]

I wanted to get the R/R as far away from the engine (and its associated hotness) as I could, and the seat lock already had threaded bosses welded to the bike's frame... making it a prime candidate for eviction in favor of more important parts.

Highly-scientific airflow tests (my bare hand at 50 MPH) indicate a substantial amount of air flowing over and around the R/R, even with it behind my leg.  It's not in a direct stream of high-speed air, but the air flowing and eddying around my left leg keeps a lot of air circulating and moving over the R/R... certainly enough to carry away its self-generated heat.

My seat lock is in the 'Tiger Parts' box in the garage.  I did not cut up my original side panel.  I found a black one from a junked bike on eBay and doctored it up to fit around the new R/R.

I'll fab up a new location for the lock, with a longer cable.

[ackme]

Ah, very good.  Thanks for the info.

ack

[oxnsox]

Looks great Stretch,  and another good how-to post.

As a note to all and any doing this, it's not entirely necessary to use the copper plate.  It is possible to get a variety of anodised alloy heatsinks from places like Radio Shack (Americas), Maplin (UK), Jaycar (Aus/NZ) or even thru mailorder places like RS.

The important thing thou is to get an anodised heatsink (won't corrode in the weather) and use heat paste/thermal grease to ensure any heat is transferred.

The MOSFET RR's will naturally run cooler than the SCR types because they deal with Regulation differently.

[stopwatch]

Hiya Stretch. I'd like to get a rec/ reg like yours, but none of the Honda ones I've seen on ebay ref a make or that particular model# FH008EB. I don't want to get the wrong one. :icon_scratch Any hints for me.. THANKS!

[Stretch]

Here's one from an '07 CBR1000RR.  FH008EB is listed as the model number under Item Specifics...

http://cgi.ebay.com/ebaymotors/07-HONDA ... _500wt_954

The listing says they have three in stock.

[stopwatch]

Was the one you got "plug and play" ? I'm wondering if it will plug directly into the wires from the stator (I've already done the sasquatch mod going to the battery).  Thanks...

[Stretch]

Nope, not 'plug and play'.  The connectors on the new R/R are much larger than the Triumph and Rick's parts.  Besides, I had trouble with the stator-to-RR connector once, so now I clip off the connectors and solder everything together.