It's been too long since I worked on my Oilhead

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Major Softie
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Joined: Tue Aug 03, 2010 1:46 pm

It's been too long since I worked on my Oilhead

Post by Major Softie »

So, the Oilhead punished me for this: it started leaking oil from the right side cylinder head gasket. Enough to ugly up the whole side of the bike and my right boot.

So, I checked it out and found that, yes, this is a known issue with the early Oilheads. In fact, the head gasket was redesigned to address the issue. My bike is 17 years old and has 56k on it, so it made it quite a while before this reared its head. Lucky me, I learn that the new gasket isn't exactly the same thickness (slightly thinner), so you have to do both sides. At least this means that both sides should be good for a very long time.

So, I do the job, and it's not bad (even though significantly more complicated than an Airhead), and I could have easily done it in an afternoon if not for the cleaning of the heads and piston crowns, which were quite carboned up for only 56k. The cleaning turned it into a two day project, what with soaking and scraping time. After I get it all together, I go to adjust the valves, and I find they are perfect. What? If the gasket is thinner, then how come the valves aren't tighter??? Did I not really have to do both sides? Oh well, maybe the re-torque at 600 miles will squish them down a bit more...

It wasn't until the next day, while describing exactly this to a friend, that I realized - in the middle of telling him about this valve clearance issue - what an idiot I am. The cams of the Oilhead are in the head, so the cylinderhead/cylinder gasket and interface do not impact the valve clearances in any way. In fact, I could have checked the valve clearances with the head sitting on the bench, and they still would have been the same.

Like I said: it's been too long since I've worked on my Oilhead. :oops:
MS - out
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enigmaT120
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Location: Falls City, OR

Re: It's been too long since I worked on my Oilhead

Post by enigmaT120 »

I had the head off an old Honda Accord a long time ago, and was putting it back together. I was told that I could adjust the valve clearances before installing the head (same reason -- overhead cam) but boy that felt weird. Easy though.
Ed Miller
'81 R65
'70 Bonneville
Falls City, OR

"Gasoline makes people stupid." -- Chuey
"I'll believe corporations are people when the State of Texas executes one." Bumper sticker
Major Softie
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Re: It's been too long since I worked on my Oilhead

Post by Major Softie »

Yeah, the Oilhead fools you though, because it is NOT an OHC. It has pushrods, but the cam is in the head - below the cylinder (as it mounts on the bike). I've never seen the pushrods out of the head, but they can't be more than 1.5" long max - probably even shorter than that. Anyway, it was the pushrods that messed with my head.
MS - out
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Steve in Golden
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Re: It's been too long since I worked on my Oilhead

Post by Steve in Golden »

My new R1200GS is a DOHC. OMG what have I done? How am I going to adjust the valves? So much for simple valve adjustments! From what I understand though the new camheads don't need to have the valves adjusted near as often.
Major Softie
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Re: It's been too long since I worked on my Oilhead

Post by Major Softie »

Yeah I found a really nice illustration of your head design. I don't even know how you adjust those valves. Maybe they have tiny little shims on top of the valves??? The drawing just doesn't make it very clear how it would be done. Maybe you exchange those little rocker arms, or a shim built into the rocker arms.

Image
MS - out
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vanzen
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Re: It's been too long since I worked on my Oilhead

Post by vanzen »

... and why should this wonderful story be posted in post 1970 airheads ?
Image
Major Softie
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Re: It's been too long since I worked on my Oilhead

Post by Major Softie »

vanzen@rockerboxer.com wrote:... and why should this wonderful story be posted in post 1970 airheads ?
Because it doesn't belong in The Speakeasy, and if I had put it in the Oilheads section, no one would have read it. Besides, it IS Airhead related: it points out how Airhead thinking shaped the way I looked at the job. I know it's a weak excuse, but how else was I going to get it in here where it actually might get read. :mrgreen:

Edit: AND!!!!
In my own defense I offer the Rupp 125cc motocross thread:
viewtopic.php?f=1&t=4960
Thank you, dwire.

"Strange background script on board topic..."
viewtopic.php?f=1&t=4625
Thank you again, dwire.

And "Don Vesco Freeway Flyer"
viewtopic.php?f=1&t=4843
Thank you, Motorhead.

I humbly submit that my phoney ass excuse for a connection to Airheads is stronger than any that can be made for any of those threads. Ha! :lol:
MS - out
Jean
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Re: It's been too long since I worked on my Oilhead

Post by Jean »

At least when you do the valves on the bench, you KNOW they are cool enough to do the job right!!
And concerning the nice picture of the 4-valve head...maybe you DON'T adjust them...just toss the whole thing and buy another.
Or the electronics get your goat (and pocketbook) long before the valves even need adjusting.
Clemson, SC
R100s, R75/5
Deleted User 62

Re: It's been too long since I worked on my Oilhead

Post by Deleted User 62 »

Yep, it's those electronics that would worry me...
Last edited by Deleted User 62 on Tue Aug 21, 2012 1:55 pm, edited 2 times in total.
Chuey
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Re: It's been too long since I worked on my Oilhead

Post by Chuey »

I would think they'd have some kind of lash caps that come in different thicknesses or maybe a shim under the lash cap.

Chuey
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