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Old 08-25-2013, 04:26 PM   #1411
JonnyCash
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You really haven't enjoyed good luck this summer, have you? Sorry to see that. Ouch!
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Old 08-26-2013, 08:18 AM   #1412
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Personally, this is time to clean the slingers. As you know, your bike has no oil filter. The slingers lube the crank which in turn, lubes the backs of the pistons. Once the slingers fill up they have to be removed to be cleaned or replaced.

The slingers get partly filled simply by the motor running in (mostly piston ring and cylinder wall). When you do a top end rebuild, the new rings and honed or bored cylinders will shed off material in it's breaking in stage. This material that is shed off will be filtered out of the oil by centrifugal force and deposited in the slingers.

At this time the slingers will be pretty full and will struggle to lube the crank and usually won't have enough oil flung out to lube the cylinder walls. This is when you start to get the serious warning signs, the cylinders will start to score and develop piston slap. The owner will pop the heads to have a look. If he or she doesn't understand what he or she is looking at, the top end will be rebuilt again (now on the last oversize). Thinking the problem is solved, he or she will ride off.

This time the slingers are so full they can't even lube the crank and the engine seizes. Once this has happened, it will be VERY expensive to revive the bike as now the new pistons are junk, the cylinders are junk and the crank has joined them! The bike has now become Ebay fodder as a "barn find" with a stuck motor.

Now's the time to clean the slingers.
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Old 08-26-2013, 10:13 AM   #1413
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Quote:
Originally Posted by danedg View Post
a friend's engine, R69S: slingers full at 40,000 mi.

Now was that the first 40,000m or the second?
I'm showing a twitch over 80,000m.
That's 32K after slingers. I wonder...[/QUOTE]

I think we all know what Dan is going to do.
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Old 09-01-2013, 10:04 AM   #1414
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Quote:
Originally Posted by Pokie View Post
Personally, this is time to clean the slingers. As you know, your bike has no oil filter. The slingers lube the crank which in turn, lubes the backs of the pistons. Once the slingers fill up they have to be removed to be cleaned or replaced.

The slingers get partly filled simply by the motor running in (mostly piston ring and cylinder wall). When you do a top end rebuild, the new rings and honed or bored cylinders will shed off material in it's breaking in stage. This material that is shed off will be filtered out of the oil by centrifugal force and deposited in the slingers.

At this time the slingers will be pretty full and will struggle to lube the crank and usually won't have enough oil flung out to lube the cylinder walls. This is when you start to get the serious warning signs, the cylinders will start to score and develop piston slap. The owner will pop the heads to have a look. If he or she doesn't understand what he or she is looking at, the top end will be rebuilt again (now on the last oversize). Thinking the problem is solved, he or she will ride off.

This time the slingers are so full they can't even lube the crank and the engine seizes. Once this has happened, it will be VERY expensive to revive the bike as now the new pistons are junk, the cylinders are junk and the crank has joined them! The bike has now become Ebay fodder as a "barn find" with a stuck motor.

Now's the time to clean the slingers.
Pokie,
The glass is half full, not half empty.
Lighten up Francis!
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Old 09-05-2013, 04:04 PM   #1415
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Old 09-05-2013, 04:04 PM   #1416
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Old 09-06-2013, 07:49 AM   #1417
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Sorry if I sounded too heavy. I've had to deal with a lot of folks that came to me with their /2s gasping their last breath. It makes me really sad to see these bikes fade away just because folks don't understand them. The really sad part is when someone just does a quick and dirty rebuild then sells the bike to an unsuspecting "budding" enthusiast only to have the bike self-destruct a few miles down the road.

I've got a 1963 R60 on the bench right now that someone had pulled down to do a re-build. They had it down to the crank but didn't bother to clean the slingers before starting to put it back together. It didn't get finished before the new owner got it. We pulled the crank to find the slingers so full they were about to start blocking the crank holes. I eneded up having to do the crank anyway but at least it hadn't seized.
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Old 09-07-2013, 05:00 AM   #1418
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it's just that you underestimate your audience, Pokie.

Not "coming across heavy" so much as "preaching to the choir".




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Old 09-07-2013, 06:15 AM   #1419
Comodo0
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Hi
I would say that these bikes are paying the price of their qualities.
They are so strong and easy at the first glance to mechanic and service that many owners did not do the right thing.
I've seen some /2 in a state so unbelievable, close to a bike found in a junk yard and that are firing anyways everyday at the first kick...
Some years ago i went to see one for sale, it was in a junkyard in a humid forest.
It was against a tree and sitting there for 18 yaers. W'eve put some gas in the carbs a kicked something like 30 times a the bike started!!!!! For one minute yes, but it started!

My mechanic is specialized in old Beemers and /2 but recently he told me he was fed up with them because every time he took a /2 and opened it it was a massacre.
Bits of /5 and 6 not to say more. Clients did not agree about the time he said he spent to make it right in a professionnal maner, so he now wants to stop working on these bikes...
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Old 09-07-2013, 06:46 AM   #1420
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Hopefully the cycle is turning on the Slash 2's.... the people who are now buying them are informed enough (at least compared to the last 30 years!) and are interested in them enough, and have money enough, to do the job correctly.

What I am trying to say......They are no longer something you can pick up for next to nothing, and maintain as if it is worth next to nothing....



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Old 09-07-2013, 09:49 AM   #1421
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Many of us are not really a part of the choir. Remeber this is Airheads so I have no experience with /2. I know it's different, I know I want one and I know I don't have the money. I also know they have slingers. But I have never had that experience so I can't relate. Thanks for the walk through Pokie. I have a better understanding now. What I got from that is after a top end rebuild the slingers should be cleaned, again!

What I'd like to ask is something that always causes trouble or at least is hard to answer. To clean the slingers the engine must come out of the bike? The engine is taken down so much, how much? How many hours labor does a /2 mechanic get to charge for this?

Sorry about your troubles Danedg.
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Old 09-07-2013, 12:18 PM   #1422
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The motor comes down all the way. The slingers are on the crank and the crank has to come out. What I used to have folks do is to remove the engine themselves, pull off the heads, cylinders and anything else they felt comfortable taking off and just give me the lower end. Usually they left on the cylinders so the rods wouldn't be flapping in the breeze. This way they could save on the labor.
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Old 09-08-2013, 06:01 AM   #1423
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Much of this topic has been covered in excruciating detail earlier in this very thread. But perhaps it's time for a refresher.
This is a /2 crankshaft assembly. I say assembly, because you will note the connecting rods are permanently fit to the rod journals that are "press fit" to the crank webs. It takes exact knowledge, a very big press and a high degree of accuracy to squish this all together. The machinist has account for the assembly to be "true" front to back, exactly 180 degrees opposed and with specific runouts on the rods. It is removed and installed in the engine case in one piece. Everything else on the motor has to be removed to pull the crank assembly. It's the press fit aspect of this assembly that designates a /2 as really Old School. Many of the bearings and bearing holders throughout the bike are press fit. One learns to heat and cool related parts for assembly and dismantling. It's demanding, labor intensive work. Which is why nobody makes 'em like this anymore...
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Old 09-08-2013, 06:18 AM   #1424
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Oil feed

Here is the crank assembly showing the tiny hole that feeds oil to the big end of the rod.


Here is the crank assembly showing one of the two slingers in place. Oil is gently pumped onto the face of the slinger. The centrifugal force of the spinning disc forces the oil to the outside lip of the disc, and then it is forced into the tiny hole that feeds the big end of the rod.


The slinger performs another function at the same time. As there is no oil filter for the motor, the centrifugal force also slings all the "suspended solids" (see Dirt and Other Junk) that are in the oil, to the outside lip where it gets trapped. This schmutz continues to build up in the lip until it prevents the oil from reaching the rod journals by plugging up the tiny oil feed hole.

Here are a set of slingers that have just been cleaned.

The schmutz reminded me of a stiff putty. It came out rather easily due in fact that the bike had been running continuously until teardown...52,000 miles. Apparently if the bike sits for a length of time, the shite stiffens up and becomes very cement like. Difficult to remove, which requires replacing the slingers. Theses slingers were JUST to the point of blocking the oil feed hole.
But it didn't matter. The crank was destroyed by the front and rear main bearings having "spun" in their holders and on the crank.
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danedg screwed with this post 09-08-2013 at 06:30 AM
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Old 09-08-2013, 06:41 AM   #1425
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And eveything else

Bear in mind, while all that's going on the cranks is also carrying the entire timing train gears driving the camshaft, the generator setup on the crank nose, and a 13# flywheel in the back that keeps everything spinning nicely.


In reality, it's a simple machine. In theory, a machine that would run forever if it weren't for those damn slingers.
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