cam swap

[cookie]

is it possible to change an airhead camshaft without removing the flywheel to get at the oil pump? i'm getting conflicting advice on the interweb.

i have a a totally mullered cam follower and it's damaged the cam lobe too

 

[Rob Farmer]

Yes you can as long as it's not a heavy flywheel bike. I've done it a couple of times on my bikes. The tricky part is lining the cam up to the oil pump again so mark the camshaft sprocket and the crankcase so you have a reference point.

The heavy flywheel bikes have a woodruff key to hold the oil pump rotor in place so you need to take the gearbox, flywheel and oil pump cover off. The light flywheel bikes have two flats on the oil pump drive so the cam can easily be withdrawn.

You will need the rocker arms loosing or removing to allow the cam followers to be pushed up enough to allow the cam to come out cleanly, this can cause problems with the barrels seating so do them one at a time and put nuts/spacers in place to hold them in place.

Drop the sump off to allow you to see what's going on and swap the cam followers.

Thinking about it you've already taken the cam followers out so you must have taken the barrels off?

 

[bumpmuncher]

sorry no idea about your question. But my question is Have you got any idea what caused it ???? may I ask what oil you used (make and spec not bothered about weight)

 

[cookie]

Yes you can as long as it's not a heavy flywheel bike.

Thinking about it you've already taken the cam followers out so you must have taken the barrels off?

that's good. it's on my R80 which has a modern looking flywheel

i'll mark the sprocket etc. as you suggest.

 

[cookie]

sorry no idea about your question. But my question is Have you got any idea what caused it ???? may I ask what oil you used (make and spec not bothered about weight)

i have only done about 5K on the bike since it was rebuilt. i didn't do the work, but i suspect a pitted, or at least worn, follower was left in the bike.

the bike was pretty quiet when i got it, but got increasingly noisier as the miles went on.
trailing it at altitude, in hot weather, then caning the tits off it on spanish twisties and motorways probably didn't help

it had clean oil, probably 20/50 in it when i got it. i have since changed the oil and used the same grade, and i think it was some ludicrously expensive, and high spec valvoline i found in the garage.

not seen the insides of many airhead beemers, but i've seen a lot of guzzis, which are almost identical as far as valve train goes. followers are always worn, sometimes pitted, but never seen one quite as bad as this before, and never replaced a cam before.

guzzi followers start off noticeably convex, or even concave, then wear flat, then pit.

this one's like a bloody surform

 

[cookie]

cam came out easy enough.

now i can see it properly, it's not major damage like the follower, but you can feel it with your finger, let alone finger nail.

i'll get a new one, or possibly a good S/H one with the sprocket already pressed on. i don't have a press, and it saves a job.

 

[richie moore]

there is a problem developing at the moment with the 336 cam and the lobes on the right hand cyilinder. the draft has not been ground so the followers do not spin and the loading wreks the cam and followers but only on the rh cylinder. i found the problem last week and bmw are looking into it. they also changed the manufacture of the followers at the start of last year but they seem to be ok.

 

[cookie]

there is a problem developing at the moment with the 336 cam and the lobes on the right hand cyilinder. the draft has not been ground so the followers do not spin and the loading wreks the cam and followers but only on the rh cylinder. i found the problem last week and bmw are looking into it. they also changed the manufacture of the followers at the start of last year but they seem to be ok.

what's "the draft"?

mine is from a left hand cylinder, but looking at the wear (see photo), the follower has maybe not been rotating

 

[Steptoe]

i have only done about 5K on the bike since it was rebuilt. i didn't do the work, but i suspect a pitted, or at least worn, follower was left in the bike.

:

It's very very common for the cam followers to end up like yours. Seen plenty over the years. They also crack/split as well.

I suggested that was the problem with [URL="http://www.ukgser.com/forums/showthread.php?t=204226&highlight=bumblebee"]Mavericks[/URL] R100GS when it got noisy two years ago, and it was

 

[cookie]

all back together now, and it's pretty quiet, even on the slightly larger valve gaps, set to compensate for the new head gaskets compressing

needs to be ridden a while before i can be 100% happy, but the signs are good. it got quite hot while i timed it and balanced the carbs, and still sounded healthy.

 

[(RIP) maverick]

It's very very common for the cam followers to end up like yours. Seen plenty over the years. They also crack/split as well.

I suggested that was the problem with [URL="http://www.ukgser.com/forums/showthread.php?t=204226&highlight=bumblebee"]Mavericks[/URL] R100GS when it got noisy two years ago, and it was

Yep those cam followers disintegrated basically into pieces. Just replaced the cam followers never looked at the actual cam to be honest May the bastards who stole it suffer the consequences