1150GS piston orientation/cam timing question

[DrFarkoff]

Ehm you shouldn't need the front cover off except the wee plastic one

Use the nut on the lower pulley to turn the crank (Clockwise only viewed from the front) TDC marks can be seen in the little port at the upper rear right of the engine casing

The cam is in each head the chain that drives it is off the auxiliary shaft so you really don't get an advantage to go in there unless you an old boxer twin rather than an oilhead?

So if you set it all back up to the marks on one side you can compensate the cam wheel in the chain

TDC on firing side both valves closed and arrers on the cam wheel point East and West Watch the notch in the cam wheel that sits into the cam itself make sure you have it 180 degrees out

You can do this easily IF the head is still off make sure the inlet valve has just closed with cam rotation being anticlockwise thru both inspection holes viewed from the rear of the motor


I think that's all correct but I may be having an Ogmios "Hard of Thinking Moment"! I am sure if I am wrong there will be a hail of flak and I will go down in Flames


Be careful tho I always wondered what would happen if I set both pistons to TDC Simultaneously firing instead of the 180 difference


Hmmm Big Bang Boxer anyone??

 

[MattW]

Be careful tho I always wondered what would happen if I set both pistons to TDC Simultaneously firing instead of the 180 difference


Hmmm Big Bang Boxer anyone??

I nominate you to try it out

 

[DrFarkoff]

are you gonna do a risk assessment for H&S

I nominate you to try it out

 

[seags]

Ehm you shouldn't need the front cover off except the wee plastic one

Use the nut on the lower pulley to turn the crank (Clockwise only viewed from the front) TDC marks can be seen in the little port at the upper rear right of the engine casing

The cam is in each head the chain that drives it is off the auxiliary shaft so you really don't get an advantage to go in there unless you an old boxer twin rather than an oilhead?

So if you set it all back up to the marks on one side you can compensate the cam wheel in the chain

TDC on firing side both valves closed and arrers on the cam wheel point East and West Watch the notch in the cam wheel that sits into the cam itself make sure you have it 180 degrees out

You can do this easily IF the head is still off make sure the inlet valve has just closed with cam rotation being anticlockwise thru both inspection holes viewed from the rear of the motor


I think that's all correct but I may be having an Ogmios "Hard of Thinking Moment"! I am sure if I am wrong there will be a hail of flak and I will go down in Flames


Be careful tho I always wondered what would happen if I set both pistons to TDC Simultaneously firing instead of the 180 difference


Hmmm Big Bang Boxer anyone??

Hi,

Yes you're right i can use the marks on the flywheel. As my cam sprockets are within one tooth i will be able to avoid the 'big bang' version although if bmw had made one I'm sure Mick Doohan would have won on it!

Cheers

 

[MattW]

are you gonna do a risk assessment for H&S

No problem:


Risk Assessment

It'll be right.

signed

MattW



How's that

 

[DrFarkoff]

I will be able to avoid the 'big bang' version although if bmw had made one I'm sure Mick Doohan would have won on it

Crowd safety may have been the worry plus it shakin it's ass to bits on the straight

Just as long as both sides inlet valve don't open and close together you'll be fine

 

[pharme]

You'd like to think so wouldn't you?

I actually did do that however as i did the second one the chain jumped a tooth. So now one side is ok and one side is one tooth out - its not something i want to guess so it looks like the front cover is coming off - hey ho.

Thanks for all the help.

Cheers

I had both heads off and when cam chain and sprockets are assembled back, I too am witnessing the chain skipping a tooth after each revolution. Is this supposed to be the case? If so, what wrong were done and how to rectify it? Bike runs well except I am chasing after knocking sound coming from the head. And the noise is really evident when running in op temp.