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Old 07-24-2013, 03:58 AM   #1
rustygardhouse OP
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1980 R65 flywheel markings

It seems that my flywheel was installed incorrectly & I couldn't read the timing marks. So I bit the bullet, jerked everything apart and pulled the flywheel off.

But...

The only markings I can find on it are OT & Z. (Cool yellow color is me)



When I read Clymers about timing, they reference an S & Z mark but for installing a new flywheel, they talk about OT & Z.

so here comes the obvious question: is there a mark missing on this flywheel or is this a new flywheel where the OT replaces the S?
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Old 07-24-2013, 03:22 PM   #2
190e
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The S mark is right there in the pic. They just drilled the hole badly through part of it. You can see the circle which is the nominal position for the hole. The hole is the actual static timing mark not the S stamping just as TDC is the line not the OT stamp. Same goes for the Z You can just see the circle/dimple that denotes the position of full advance.
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Old 07-24-2013, 04:03 PM   #3
disston
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To replace the flywheel using the OT mark is easy. Use a plastic straw or a bamboo chop stick to find TDC on either piston. Careful to not trap tool inside the cylinder by raising piston too fast. You will be able to place piston at TDC with in 1 or 2 degrees which is close enough to put flywheel on with OT mark positioned for the timing window.

Nobody mentioned and we always mention this, Did you block the crank to prevent forward movement?
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Old 07-24-2013, 04:42 PM   #4
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This may (or may not) help... it's off of my R80G/S

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Old 07-24-2013, 05:04 PM   #5
rustygardhouse OP
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OK got it.

Nice of them to drill out the timing marks! I'll get them filled with yellow paint as well.

Thanks all!
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Old 07-24-2013, 11:53 PM   #6
pommie john
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To repeat Disston's question ( it's important) did you block the crank before you pulled the flywheel off?

The flywheel is what keeps the crank in the correct position. If the crank moves forward when the flywheel is off, the crank thrust washers can fall off their pins and when you bolt the flywheel back on you do major damage.
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Old 08-06-2013, 06:04 PM   #7
rustygardhouse OP
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complete the circle

Thought I'd complete the circle on this...

Made sure the timing marks were filled with yellow paint & reinstalled the flywheel in the correct location.

Buttoned everything up & finally got a start on it last night.

Checked the timing &...

According to the marks, it was 10 deg too advanced!

Reset the timing to be correct, readjusted the idle speed and balance the carbs at idle & 4k rpm.

Haven't given it a test ride yet & I'm looking forward to this!


As an OBW (oh, by the way...) the reason I did this is, believe it or not, to get the carbs running right.

When I first got the bike, it would stumble when I came off the throttle.

I sent it to the local shop to have the timing checked, the valves lashed & the carbs balanced.

Little did I know...

Turns out that the top cap in the RH carb was loose so when I came off the throttle, the needle valve would slam shut & choke the carb.

So I rebuilt both carbs, sealing the top caps in the process.

But I could never get the bike to run right. I kept thinking I screwed up the carb rebuild; the timing & valve lash were adjusted by the shop so they CAN'T be wrong.

& just when will I ever learn...

I finally checked the valve lash & found the LH intake to be 0.025".

WTF!!!!

So that lead me to double check the timing...

& just how did the shop check the timing if the flywheel was incorrectly installed?

What really pisses me off is that I know better...

But apparently not.
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Old 08-06-2013, 06:40 PM   #8
disston
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The only way to be sure it is done right is to do it yourself.
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Old 08-06-2013, 07:04 PM   #9
ME 109
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Quote:
Originally Posted by disston View Post
The only way to be sure it is done right is to do it yourself.
Do you mean blocking the crank?
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Old 08-06-2013, 07:17 PM   #10
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Originally Posted by rustygardhouse View Post
OK got it.

Nice of them to drill out the timing marks! I'll get them filled with yellow paint as well.

Thanks all!
All '79-'80 R65 flywheels were marked that way.
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Old 08-07-2013, 01:02 AM   #11
disston
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Quote:
Originally Posted by ME 109 View Post
Do you mean blocking the crank?
Either Rustygardhouse knows about the problem with blocking the crank but refuses to pay it any lip service because he doesn't like being told or considers it insulting to be reminded about this. Or he merely forgets each post to tell us he has blocked the crank. Or he has no idea what this is about and doesn't want to ask.

We've tried, it's all we can do. I don't loose any sleep over it.

It is possible to do the job and not block the crank but have nothing bad, as in the main bearing coming off it's locating pins, happen. The bike started so either he did block the crank or he was lucky.
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Old 08-07-2013, 11:02 PM   #12
rustygardhouse OP
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crank blocking

OK you caught me; I normally don't read things in the posts that don't directly pertain to my question...

So, no, I didn't block the crack; it was not mentioned in my version of Clymers. Before starting this, I triple read all the cross referenced sections to make sure this is something I wanted to try.

Odd Clymers wouldn't mention something this important...

The bike started so it's either fine or getting ready to crater. Time will tell.

I might have got lucky; I put the crank in TDC position, then pulled the flywheel off, didn't touch the crank until I reinstalled the flywheel & used the old flywheel bolts to evenly draw the flywheel onto the crank so I didn't pinch the new flywheel o-ring. In other words, I did nothing to shift the crank forward.

Sometimes, ya get to eat the bear...
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Old 08-08-2013, 11:23 AM   #13
disston
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You were lucky. But it is true that if you don't move the crank or bump it or knock it off your work bench most times it will be fine. The thrust bearing doesn't want to move, it has to be made to move for there to be a problem. But that does happen several times a year on this list, by my count.

Yes, Clymer's does not mention it and it is one of the things that we regularly fault them for.

If the bearing was knocked off it's pins it would have seized the crank when you put it back together. So no future pending dooms day, this time.

Try to pay attention. We can be really funny sometimes and you might miss something really funny.
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Old 08-08-2013, 11:55 AM   #14
Big Bamboo
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Quote:
Originally Posted by disston View Post
The only way to be sure it is done right is to do it yourself.
..and it's also the way to know if it's done wrong. ( was I funny? )
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Old 08-08-2013, 02:30 PM   #15
disston
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..and it's also the way to know if it's done wrong. ( was I funny? )
I would call that abstruse but it does also have a humorous edge to it.
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