Another Scrambler project

[woodgeek]

So, I purchased a 1985 K100RT last weekend. After looking at a lot of other builds, I’m probably going for a military scrambler look. Here are some pics of my K from the Craigslist ad and after I began taking the fairing off.

[woodgeek]

Here are some of the inspirations for the look I’m going for.

[woodgeek]

I opened up the fuel tank today. This bike hasn’t been titled since 2000 so safe to say the fuel in the tank is almost 20 years old.









Here’s a pic of the ancient battery and the new one that’ll go in its place.

[woodgeek]

Working on getting the tank cleaned out. 50/50 mix Oil Eater and water sat in there overnight.

[woodgeek]

Not much new to report. I rinsed out the tank and it needed a little more soaking. This time I put some LA's Totally Awesome Cleaner mixed with water. Will check it again tonight.

Injectors are packaged up to be sent off to Mr Injector for cleaning. Fuel pump vibration and strainer have been ordered from EME. Also ordered gaskets so I can check valve clearances. I'm going to go with a Carter P74095, simply because they are a known quantity and an easy pump to find. I didn't want to pay for a Bosch/BMW part but I have no idea where Enduralast or the other fakes are made.

[Laitch]

I rinsed out the tank and it needed a little more soaking.. . .  I'm going to go with a Carter P74095, simply because they are a known quantity and an easy pump to find.

White vinegar works wonders cleaning aluminum tanks.
Does the diameter of that Carter pump match the diameter of your fuel pump damper assembly? These assemblies and pumps have often been switched by previous owners. What is the diameter of your existing pump? Adaptions can be fabricated to fit a narrow pumps into wide damper assembly; a wide pump can't be shrunk, of course. :giggles

[woodgeek]

The diameter of the carter fuel pump is smaller than the original fuel pump. Someone used fuel cell foam as a spacer and fit the carter fuel pump inside the Bosch "can". I’m thinking of doing this. The only thing that worries me is, what happens to the fuel pump when the foam begins to break down? Link to the article: http://www.mychamp.com/K100/4/

[Laitch]

.  . .  what happens to the fuel pump when the foam begins to break down?

If the foam breaks down, the fuel pump will break down, the fuel filter will clog and forward motion will cease, unless you're on a downhill run. You'll just need to believe what you have read or find some corroborative information.

It looks like an arts-and-crafts project so at least it will keep your hands busy and keep you out of trouble.

[woodgeek]

It looks like an arts-and-crafts project so at least it will keep your hands busy and keep you out of trouble.

:hehehe


I've been thinking more about what might happen if/when that foam breaks down. Compared to the mass of the vibration damper, there's not much there. Also, when foam breaks down, it sort of disintegrates. The damper turned to a gooey sticky mess just destined to clog something. . .

Lots of racers use fuel cell foam in their cars. When it disintegrates they replace it. I haven't read any threads wailing about clogged filters or clogged injectors so  :dunno2:

[Martin]

You could try clamping fuel resistant fuel line around the inner pump. It is available in a few different diameters, cut three pieces that can go around the inner pump, split the hose and secure with stainless steel cable ties. Or cut the hose about 1" short of the diameter thread stainless ties through the hose and tighten in the gap. You will need to stagger the joins at 120 deg. Once you have the hose secure on the inner pump push it into the old shell.
Regards Martin.

[woodgeek]

White vinegar works wonders cleaning aluminum tanks.

I thought my tank was close to clean so I rinsed with hot water and dumped in a gallon of vinegar to slosh around. Then I made the mistake of feeling around where I couldn’t see. Inside the well where the fuel pump sits and I couldn’t see is a bunch of melted damper that’s adhered to my tank.

Now I’m gently scraping with a flat blades screw driver getting this black hole cleaned.

[Laitch]

Inside the well where the fuel pump sits and I couldn’t see is a bunch of melted damper that’s adhered to my tank.

Relax. Let it soak for a few days immersed in vinegar then remove the sludge. It should come off much more easily after that using a shop rag and a piece of hardwood or plastic as a scraper. I'd be reluctant to trust my finesse using a metal gouge like a screwdriver.

[Laitch]

Someone used fuel cell foam as a spacer . . .

The someone asserts this fact:

The foam normally occupies 3% of the volume, leaving 97% for fuel. The foam will allow gasoline to surround the fuel pump. This is important because in-tank fuel pumps are designed to be cooled by the gasoline that surrounds the pump.

but then he does this during the assembly which seems to defeat his assertion. That compaction would tend to reduce the foam's ability to hold enough fuel for cooling. Radiational cooling probably still happens.

In addition, it seems like some foam works with alcohol fuel and some doesn't, so there's that to consider. Then I read about the effective use of nerfballs for fuel cell material. That would add a fun element.
 :yippee:

[rbm]

That individual chose to wrap a piece of foam completely around the circumference of the pump.  What you said. Laitch, seems reasonable to me.  It lead me to think that another way to secure the new pump is to just use four or five long striips of fuel tank foam.  That would leave a good portion of the pump surface exposed to fuel contact and cooling.

[woodgeek]

Getting ready for the intake rebuild


 

[Skunky]

Perfect opportunity to clean and polish that aluminium. Block up the holes first.

[woodgeek]

Perfect opportunity to clean and polish that aluminium. Block up the holes first.

That’s the plan. [emoji6][emoji106]
I can’t believe the four manifold fittings that bolt onto the intake cost $50 each. Mine had tiny cracks and I was replacing the rest of the intake rubber anyway.

[Skunky]

I am trying to leave mine in place. That way I won't need to replace them.

[woodgeek]

Cleaned and rebuilt Brembo calipers.

[woodgeek]

Rear caliper cleaned and ready to be reassembled.

Front stainless lines also got a cleaning.

[Skunky]

Rear caliper cleaned and ready to be reassembled.

Front stainless lines also got a cleaning.

Is your front stainless line one piece. if it is how long is it

[woodgeek]

Is your front stainless line one piece. if it is how long is it

There are two lines. The previous owner replaced the original rubber lines with stainless.

[woodgeek]

Valves measure good.
And ‘yay’ for new rubber bits!

[woodgeek]

Old switchgear vs nice, new switchgear.

[Laitch]

Old switchgear vs nice, new switchgear.

You might be interested in one of prakash's posts concerning switch gear. Some sprucing-up of your old gear could bring you some bucks. In fact, you might be interested in the entire thread if you haven't seen it already.