BMW F650 Forums banner
1 - 4 of 4 Posts

·
Registered
Joined
·
26 Posts
Discussion Starter · #1 ·
bmw f650 funduro 1997

correct spec: 0.10 - 0.15 mm

one of my exhaust valves i can fit a 0.15mm quite easily in but not a 0.20mm in, adjustment needed?

the other exhaust valve i can fit a 0.15 but i really have to push it in, so no adjustment is needed

then one of my intake valves, i can shove a 0.08 feeler gauge in, not a 0.10. too tight by 0.02.


so there are a few things i'm wondering. the shim adjustment seems quite complicated, not sure i can tackle the job, probably would have to take it to a machanic


can i keep riding for a while like this? is the adjustment needed? on both? or only the intake valve?

i heard valves get tighter with time, so the exhaust one might not be an issue?
 

·
Registered
Joined
·
335 Posts
Valve clearances change but all sorts of factors come in to it;
Valve seat wear (causes gap to close up)​
Valve bucket \ shim wear (causes gap to open)​
Cam bearing wear (causes gap to open)​
Cam lobe wear (causes gap to open)​

The job is involved but not difficult but you must be methodical and have the correct equipment and be able to read a micrometer.

On those readings, I would not bother unless they change at the next inspection. I ran an early F650 for 30 000 km and never needed to do any valve clearances
 

·
Registered
Joined
·
26 Posts
Discussion Starter · #3 ·
Valve clearances change but all sorts of factors come in to it;
Valve seat wear (causes gap to close up)​
Valve bucket \ shim wear (causes gap to open)​
Cam bearing wear (causes gap to open)​
Cam lobe wear (causes gap to open)​

The job is involved but not difficult but you must be methodical and have the correct equipment and be able to read a micrometer.

On those readings, I would not bother unless they change at the next inspection. I ran an early F650 for 30 000 km and never needed to do any valve clearances
ok - guess i'm gonna to my 2000km trip and change them with my gran pa, i'm a bit obsessed with maintenance so i think i'm gonna adjust them, wanna make sure my engine is running as well as it can
 

·
Registered
Joined
·
9 Posts
Experienced motorcycle mechanics tell me that exhaust valve clearances generally close up due to valve seat erosion. If not checked and corrected the valve will eventually not close and a burnt valve will result.
The opposite occurs with inlet valves, as stevedixey describes valve bucket and cam wear will open the valve clearance.
I seek advice from experienced members regarding inlet valves. My 2001 gs is having its first check of valve clearance.at 21000kms. The exhausts clearance are within limits but both inlets are between .08 and .09. Is this typical of F650 engines? That inlet valve clearances close up and Is valve seat wear the culprit? I've been advised to leave them as they are and with more use the clearances come back into the .IO -.15 mm range.
 
1 - 4 of 4 Posts
Top