onsdag 2 januari 2019

Big problems with one carburetor...

After getting the ignition and electrical systems on to the bike it was time to start thinking about the rest of the cables and also the carburetors. As you might remember I did clean one of them about one and a half  year ago or so, but I never got around to do all three of them at that time. That now shows to be a major problem. I vaguely remember one of the throttle slides being stuck in the carb body but at the time I figured that would be no problem once I started working on them.

Big mistake!

A couple of weeks ago I took all three carbs out to take a closer look at them. The problem was a bit larger and also involved a stuck choke plunger and a rusted solid throttle cable. If I had noticed these things earlier I might have figured out a plan and done something about it right away. Now I was facing this problem when everything else was moving forward and good progress was being made. Well, no time pressure.... right?

The already cleaned carburetor is on the far left here. To be honest, that clean-up won´t be sufficient today. I´ll have to do all three a bit more seriously this time. My original carb caps are also there, badly cracked and ready for the bin.... I bought copies from John Bova in Ohio a while ago. I´ll try and clean these up and treat them with some rubber-mending-compound an see how they turn out. I have no high hopes.

Here´s what I have to work with. Dirt and grime is no big deal. Oxidation and stuck parts are much worse. The carb on the right here let go easily of both throttle slide and choke plunger. An easy clean, later on. Those cable rubber parts are actually in rather good condition. Both types are readily available on eBay, but I believe I can reuse them all.

Here´s the one causing all the trouble. You can see how corroded the brass parts are and we can only imagine what it looks like on the inside. Everything is completely dried out after 40 years in the barn. Well, my restoration came to a grinding halt here, to say the least.

What I was facing here, so far,  was the stuck slide and the stuck plunger. Here I have unscrewed the brass choke plunger housing and carefully tried to pull on the cable to remove the plunger from the body. Stuck solid. OK, I filled it up with penetrating oil and went on to the slide instead...

I removed as much of the gore I could by compressed air and sprayed the body and slide with 5-56 (my penetrating oil) over and over .

The thing with penetrating oil is you need to get an ever so small movement in the stuck parts for the oil to penetrate and do its magic. Here I had the same problem in two places on the same carburetor. The stuck throttle cable actually worked in my favor  on the slide. The cable was rusted solid inside the sheath just above the adjuster. So, by carefully unscrewing the carb top lid I put more and more pressure upwards on the throttle slide. At first it didn´t move at all, so I brought out a slightly bigger artillery.

My beloved torch... Heat is a wonder worker when it comes to stuck parts. By carefully (and I mean carefully...) heating the carb body, putting more pulling pressure on the slide by unscrewing the lid a bit more I finally got movement. It started going upwards and I knew that this battle was won! More 5-56, more heat and after a while there it was....

Slide out! One down, one to go. Now I could also start working on freeing that carb throttle cable. More later on that part of the job. 

The retched choke plunger was still stuck solid.... I knew I had to be patient and not pull to hard on the cable. That small brass part is very easily broken. The cable attaches to the top part by a slotted hole in the plunger and that makes the plunger extremely easy to ruin. 

Braking the plunger was plan B or maybe even C. I figured the plunger would be the same as on the street bikes, but I really didn´t want to drill that broken brass part out of my H1R carb body. Plan B was to simply let it sit for a few days with penetrating oil in all channels going to and from the choke system and figure out how to proceed with these problems while making my last working trip to LAX just before Christmas.

 As I was planning these measures to free my plunger I also realized that IF I wouldn´t win this battle I was in for a much larger problem, That drilling solution....No, didn´t fancy that one bit!

I recalled being offered a set of carbs from a fellow H1R owner in Belgium about six months ago. I opted out at that time. A quick e-mail confirmed he had another set (!) available. Complete and in good condition. 

This time I didn´t hesitate. Better safe than sorry. I just might have to replace one of the carbs here. I fully understand you don´t want to split a full set of carbs (I wouldn´t either...) so I bought them all three. We decided to wait with the shipping until after Christmas to avoid the chaos during peak shipping season. 

For now....Back to the throttle cable!

Here´s what I did before going away for three days working. I split the cable at the 3-into-1 joint, hooked up the two free cables and filled the joint with a mixture of penetrating oil and gear oil. Gravity pressure downwards into the stuck cable... A little wiggling and jiggling of the cable to get that much needed movement should do the trick. 

So, I left for work leaving my throttle cable hanging from the bench having ordered a new set of carbs from Belgium due to a still stuck choke plunger.... To say I had some things to think about is an understatement! During that trip I did come up with a plan to free the plunger....

Back from work I started that plan. It involved making a couple of tools to get to the stuck thing inside the carburetor body. First i had to make a tool to get the spring out of the way in order to reach the plunger with the other tool. I made my own "spring retaining tool" out of an old clamp I had in the garage. I made a large slit at the bottom part and a smaller one on top. My plan was to hold the spring compressed inside the brass housing while I fettled with the plunger.

It actually worked kind of OK... here it is. I had to wire it to keep it in place, but the spring remained inside the housing and when the adjuster turned fully in I got enough room to work with.

There it is... Stuck like H-LL! My plan was to get down there and carefully turn it to get that movement needed for the penetrating oil. Time for tool number 2 of this plan. "The plunger turning device".

An old, and very cheap, screwdriver served my purpose perfectly. It had the correct width at the blade and I could easily make it a bit thinner to enter the slot in the plunger. I just had to make a slit in the blade to accommodate the cable exiting the plunger.

To the right here you see the plan illustrated on one of the already extracted plungers.

Gentle and precise heating of the carb body at the area around the plunger, more 5-56 and a few gentle knocks with the small mandrel and at last a twist with the "plunger turning device" did release the little bugger! 

The sense of victory in my mancave was enormous at this point in time. Not only did I save the plunger, which could have been easily replaced, but also the cable and the carb body. Thanks a lot!!

Now I have a set of "special Kawasaki tools" for carburetor body repair work.

I´m rather puzzled by the fact that one of them could get that stuck while the two others were completely loose. They were stored in the same barn and sat in the same open box for more that 40 years. 

As you can see the plunger was a bit damaged at the top in exactly the way I was afraid to brake it off completely by pulling too hard on the cable. I was able to reverse that damage by carefully bending the top parts back together.

Here they are, all three plungers. Guess which one was stuck? Yeah, not too hard...

OK, next up are the cables. I would much prefer not having to rebuild them. I know I can, but it is a pain to get the correct length measured and tricky to get those small nipples correctly soldered to the cable. Better try to save the ones I have! That work is up next and in the next post.

Stay tuned for more!


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