Jon Wold

Is there some kind of four-handed magic required to push the crank back in without busting the crank ring?

grcourtney

My Feedback: (1)

use a small zip tie to squeeze the ring. fish it around the ring after you have partially installed the crank. not very easy but it does work..

gary

Wasson

Jon,

With a little bit of practice, it can be done by one person without too much trouble. The YS160 is easier to handle than the YS170 as there is a slight bevel in the crankcase to guide the ring into place.

One way to tackle the job is as follows:

# Purchase a solid alloy rod of around 1 mm diameter and cut it into 5 or 7 lengths of around 75 mms each. Debur the cut edges with some fine emery cloth.

# Push the crankshaft in to the rear of the crankcase with the gap in the crank ring pointing upwards. Use your fingers to compress the ring until the crankshaft engages in the rear of the crankcase and use a wooden dowel (of about 10 mms diameter) to tap it forwards very gently until the ring presses up against its seat

# The next bit is the slightly tricky bit. Take the first of the 1mm alloy rods and gently push it into the gap between the bottom of the crankcase and the ring i.e. at the 180 degree position. Place a rubber band around the rear of the rod and stretch the free end of the rubber band around the front of the crankcase to hold the alloy rod in place. Take the second and third alloy rods and using the same procedure, place them in the 120 degree and 240 degree positions. Then take the final 2 alloy rods and place them in the 60 degree and 300 degree positions.

# At this point you should have 5 alloy rods equally spaced around the crank ring, each held in place by a rubber band. If you have done it carefully, the gap at the top of the ring should be almost closed. If not, you can use 1 or 2 additional alloy rods to close the gap further.

# Once the gap is closed, use the 10 mm wooden dowel to tap the rear of the crankshaft until the ring moves forward into its seating position. Whatever you do, make sure that you use very gentle taps. Don’t try and force it, otherwise you will crack the ring and have to pay around 20 Euros for a new one!

If you haven’t any 1 mm alloy rod you can cut up some spacers from old lollipop sticks. These will do the same job but they will only last for one rebuild. If you are likely to be replacing your own bearings and seals fairly regularly, it is worth making the alloy rods which can be used time after time.

I’m sure there may be other methods (including the one that Gary has described) that work equally well, or even better. However the above technique requires no special tools and with a little bit of care and patience should work every time.

Best of luck.

Bob

apereira

Put a turn of clear tape around the ring compressing it, just enough to hold it, insert the crankshaft and pull the tape.

Regards

DagTheElder

Hi Jon!

Give me a call(90187441) and I will tell you about a simple tool that prevents you from destroying this expensive ring. Sorry i cannot show any photo. My camera found it opportuned to shut down.

Dag

Jon Wold

Thanks guys! The YS is put back together. I still have some switch wiring to do before I can try the CDi but at least the engine and low oil kit is in place.
I used the zip tie trick and it slid in on the first go! It was a lot easier than I first imagined.

Dag! I heard rumours you made a tool out of a Coke can, did that work for you?

DagTheElder

Hi Jon!
Yeh, the Coke can tool work the same Way as a tool for inserting pistons into an engine. It compress the rings and it have some lugs on it to prevent it to follow the crankshaft and rings ito its seating. The zip tie works the same way, difference is metal vs plastic.

Regards

Dave Harmon

Here is how I did it.
Bob Wasson....I tried for hours to get this thing back together using a similar method as you describe but I eventually had to give up....I just couldnt do it.
Same thing trying to use a Coke can......I didnt think of the zip tie...sounds good though.

So....I scrounged a brass sink extension from the junkbox and cut a band off it.
I had the shaft back in there almost immediately.

DH

Wasson

Dave,

I really like your proposed method. Provided that the brass ring is of the correct thickness, it strikes me as an excellent way of doing it. (Probably closest to the classic car piston ring method too.)

What else can I say, apart from the fact that I didn't have a spare brass sink extension in the workshop at the time?

I have used the method I decribed on numerous occasions and it works every time. I wouldn't have proposed it otherwise. With just a little bit of practice, it takes longer to describe than it takes to do - and my fingers are arthritic!

Several of my colleagues have also used it and it seems to work for them too. I suspect that Dag the Elders Coke Can method, Gary's tie wrap method and Aperiera's clear tape method work for them also.

Great that we can share various ways of approaching the job on a forum such as this. Sorry that some of the methods didn't work for you. Maybe its inevitable that what works for one person doesn't always work for someone else.

Bob