Saturday, May 14, 2011

Friday the 13th "incident"

Yesterday, Friday the 13th, I was riding home eastbound on Arapahoe road at the peak of rush hour after another long day at work.

I was riding Brigitta, my '87 R80 Airhead Beemer which of late, had been exhibiting some climbing idle issues when warm.  I thought I'd dealt with such by turning the fuel mixture screw inwards or clock-wise 1/4 turn and things indeed had been stable.

As I crossed under the overpass for the I-25 super slab, her rpm's went into the 6000 range and her engine raced accordingly since I was only going perhaps 15 mph in the heavy traffic!  Not good.

Luckily, just letting out the clutch a bit more would settle things down enough for controllable riding.  I pulled into the Honda dealership, engine racing as I coasted to a stop.

I jiggled the throttle cables going to the carbs and the idle settled back down to normal once again.  Luckily, I'd not drawn anyone's attention with my racing engine sounds.

The engine still running, I put her on the center stand and tried jostling the splitter assembly where the throttle cable from the throttle grip enters and pulls on the two separate cables that go to each carburetor.  Voila, the problem went away, I could blip the throttle and it'd settle down nicely when released, as expected.

The ride home went fine and I took the 30 seconds or so to remove the gas tank off the motorcycle to expose her wiring/cabling/fuses and relays:

 Removing the gas tank on Brigitta is vastly simpler and faster than on Vikki, my '04 Suzuki V-Strom

Here's a shot of the splitter for the choke, I couldn't get a good angle on the one for the 
throttle cables but you get the idea.

I removed the heat damaged (after only 90,000 miles, dang Teutonic engineering) rubber covers and lubricated the cable where it enters the splitter assembly so that the cables now rotate easily within the small housing they connect to.

Did that on both ends, on both the choke and throttle cable splitters.  Replaced the rubber boots, wrapped some electrical tape around them since both were heat-cracked.  That should take care of the "sticking throttle cable" situation hopefully.

As long as I had the tank off, I decided to renew the heat sink paste one uses to transfer heat from the Ignition Control Unit to the heatsink:

 The silver plate is the heat sink, the black object is the ICU bolted onto it.
The heat sink paste that remained was still fine but enough had been used up to require more.

 Here's a view of the heat sink and the ICU, now separated, before I put more heat sink paste on.

This is the stuff I used, works fine, not expensive.
This tube has lasted me since I got the R80 back in 2008.

The above job done, I put the R80 back together.  Total time, perhaps 30 minutes or so.  

We'll see how she does on the commute next week.


Allen Madding said...

My years of working on street cars and race cars made me start thinking that either a cable was damaged or a simple lubing would cure it. It was nice to both see and read the confirmation of my thinking.

It is fantastic when you caan resolve these kinds of issues without paying thru the nose to a dealership repair shop.

Enjoy your riding!


SonjaM said...

Dear Dom, if I were to go on an epic ride, I would gladly take you with me as my personal mechanic. Knowing this stuff and being able to fix it must give you some additional confidence when traveling in less frequented areas.

Anonymous said...

There's few things more satisfying than 'fixing it yourself'.

Steve Williams said...

When I read this I thought you were going to say you dumped the airhead for a nice new Goldwing.

Each time I read something like this, a rider who fixes something on their machine, I get sort of nostalgic for younger days when I was more adventurous and interested in wrenching on things myself.

Maybe someday I'll remember this post and try and fix something too. If anything ever goes wrong with the Vespa...

Steve Williams
Scooter in the Sticks
Follow me on Twitter

RichardM said...

Nice! No expensive parts or dealer visits involved. Don't you just love the simple stuff...


redlegsrides said...

Allen, yep, always a good thing to be able to diagnose and fix the simple things...thanks for writing in and confirming.

SonjaM, dunno about being anyone's personal mechanic, I'd hate to let anyone down.....still, I try to help where I can. Thanks for the kind words though, as to having more confidence in lesser traveled areas, I've had pretty good luck so far and carry a lot of tools!

NoName, I quite agree, thanks for reading and commenting.

Steve, you went and jinxed yourself!