86 k75 with sprag clutch issue, need to start it to fix it. Suggestions request

[daveson]

Thin oil will thin out thicker oil,  but not as good as something that cuts oil, like brake cleaner. Put a bend at the tip of the probe so you can spray though the hole up, down,  front and back.

I'm going to expose now my true,  rough as guts self ( I'll blame it on my past years as a formworker) I'd use petrol (gas) I'd spray it up,  down,  in,  out all over the bloody place. I'd use heaps,  and I'd do it again too. And again and again.

Don't crank it,  drain it.

I love the smell of gas in the morning, it smells like.... Victory.

[alexg]

I remember that DKW 1000 FWD transmissions had something called "rueda libre" in my native language. The thing was a sprag clutch and would start failing because people would add high pressure additives to the standard gear oil (Molykote comes to mind). The only way to revive the thing was to disassemble the tranny, soak the "rueda libre" in a slurry of very fine valve grinding compound and thin oil, and give it a good workout.

Would it be tooo bad to add a few dabs of an abrasive into this thing, and then flush the tranny several times to avoid contamination?

[Laitch]

Would it be tooo bad to add a few dabs of an abrasive into this thing, and then flush the tranny several times to avoid contamination?

It isn't in the transmission. It's nested within those gear wheels at the magenta arrow point.

sprag clutch and freewheel.png (67.48 kB . 751x576 - viewed 563 times)

[Laitch]

Here's a well rendered pictorial explaining what's what.

[volador]

Would it be tooo bad to add a few dabs of an abrasive into this thing, and then flush the tranny several times to avoid contamination?

You may be on to some thing there instead of dropping teaspoons of moly-powder nothing like a little valve grinding compound
Brilliant!

[Laitch]

You may be on to some thing there instead of dropping teaspoons of moly-powder nothing like a little valve grinding compound
Brilliant!

Combine them and the result is the industrial equivalent of creamy peanut butter.

[alexg]

"It isn't in the transmission. It's nested within those gear wheels at the magenta arrow point"

You are right, it is in the engine; forgot that detail. Even better, the engine has a filter, and a lot more volume of oil vs the tranny. And not many ball bearings.

[Laitch]

Even better, the engine has a filter, and a lot more volume of oil vs the tranny. And not many ball bearings.

Let us know the result of your trials. :-)

[The Mighty Gryphon]

Post the VIN so in the future we can avoid it.

[Laitch]

Post the VIN so in the future we can avoid it.

Spragsand® It's a miracle for your engine!

[daveson]

Actually, fix your no start problem first. When you get it going, using fresh oil with one of the suggested additives, or using the diesel oil suggestion, the sprag will free itself up. You might just have to push start it the first few times. Rough as guts suggestion #2; I often used to pour a quart of diesel into the oil before an oil change and let it idle for five minutes, before dumping the oil. I think of diesel as just a thin oil.

With the fuel cap removed, you should be able to see fuel returning to the tank, with an attempted start.

[filmhog]

Agreed, I would like to get it started....again.
I spent the last 4 days injecting brake cleaner into the 3 oiling holes. I did it several times a day and also got it wet and then flushed it with another blast.  Yes I drained the oil before hand and left it open to vent and drain the brake cleaner.  Buttoned her up today and got some rough contact then no engagement.  Back to square one.
If it were a gummed bolt, I would put heat on it to loosen it.  Would a heat gun provide enough heat to the sprag housing part to try and unstick?  Anybody used that?
Yes, I need to start it and let the detergent oil and additives do their thing.
Also as an update, Im taking apart the front master that is leaking and will see what needs to be cleaned or repaired.  Plastics are off, cracks repaired with epoxy (flex or accident damage from POwner), and plastics are sanded.  Ready for paint.  I would love to get it started before it goes on the lift for winter storage and rehab.
I have nothing but time so I'll just work at it easily.

[Laitch]

If it were a gummed bolt, I would put heat on it to loosen it.  Would a heat gun provide enough heat to the sprag housing part to try and unstick?  Anybody used that?

You'd be the first; I haven't read about that being used yet. It's time to try something other than brake cleaner. Which other of the elixirs recommended here have you tried and how many times have you tried them? Brake cleaner wouldn't have been one of my choices.

What's needed trying here is elevating the rear wheel from pavement, placing the transmission a higher gear, getting that wheel rotating at a brisk pace then popping the clutch. You could use a bicycle or electric motor to rotate the rear wheel. Desperate times take desperate measures; danger can be its own reward. You don't need to be on it or pushing it. You just need to be sure it's stable when it starts and that its front brake is engaged so if it drops off its support, it won't easily power through a wall. Old mattresses make excellent wall protection, usually:-)  Anyway, it's the only way you'll be able to start it under the circumstances unless enough sprags loosen in the clutch housing.

Here's the idea. As indicated previously, rustic solutions are within reach. :-)

Set up for YouTube. Many here could be interested and have no other lives in the winter.

[volador]

Save your quid and save the detergent oil and there additives for later. That is going to need many miles to do its thing.

A cup of kerosene in crankcase oil when running from the starting block or douche with lacquer thinner or acetone in a spray bottle with tip extension

Heat gun with a narrow tip couldn't hurt on a moderate/medium setting

Or try some vinegar

[Laitch]

A cup of kerosene in crankcase oil when running from the starting block or douche with lacquer thinner or acetone in a spray bottle with tip extension . . .Heat gun with a narrow tip couldn't hurt on a moderate/medium setting . . .Or try some vinegar

The 5B Sisyphean Society's in-house sprag cleaner sends you best wishes.

5BSisypheanSpragCleaner.jpg (49.41 kB . 768x531 - viewed 534 times)

[Martin]

I've seen a 70's Honda four been started via hand starting. The bike was on the centre stand in gear, the rear tyre was grabbed and given a sharp pull and it started. I can't tell you what gear it was in or even the size of the engine but it was not the 750. It might be a bit more complicated on the Brick. I did find this   We also used to start race Karts on the pit stands by wrapping seat belt webbing around the rear tyre and using like a pull start. I accept no responsibility for any damage to you or your bike if you try this, but piccies would be appreciated.
Regards Martin.

[johnny]

greetings...

did you deoxit the sprague gound wior...

j o

[volador]

The 5B Sisyphean Society's in-house sprag cleaner sends you best wishes.

I love the smell of lacquer thinner in the morning. YeeeHaaaw

[Laitch]

How I broke my wrist then collected unemployment for 12 weeks while learning to speak Finnish. An Internet success story.

[volador]

No seat belts required

[cycleman]

Fix your non start issue first. Make it much easier if you can get it running by push starting. If you are going to be spraying into the holes on the sprag, I would use something like Sea Foam spray as it is both a penetrating and lubricating oil. Brake cleaner acts as a drier which will remove all the lubrication from that area, not really what you want.

The early Gold Wing 4 cylinders also used a sprag clutch starter system and they were known to cause problems.  My last GL1100 a 83 model, I bought as a non starter and the fellow had given up on getting it running. It was a sprag clutch not engaging. I changed the oil and filter and put in about 100 cc of Sea Foam into the oil. With the help of my wife we were able to push start it and get it running.  I then went on a ride for about an hour.  I got home, shut it off and then the starter engaged intermittently, so I went on another longer ride. Got home, changed out the oil and put in the right weight of oil.  Never had any problems thereafter. A lot the the sprag problems with the GL1000 was folks running 20-50 oil.  Maybe if you lived in the desert but for the rest of us, it was too thick for a water cooled bike.

My current K100RT is an 86 model that sat for likely 25 yrs, some outside. It has about 15 K miles on it. I bought it off the previous owner who had done some restoration work on it to get it back on the road but he didn't want to spend any more money on it. It has an intermittent sprag issue. I've put about 2000 miles on the bike since I bought it, changed the oil and filter 3 times and with the last oil change I went with Mob 1 15-50. From what I've read that seems to be the choice of oil for this bikes. If the sprag issue continues I'll try the Sea Foam treatment.