Busy weekend

[Steptoe]

An 1100 came in with both headgaskets blowing - straightforward enough job .

Righthand replaced, onto the lefthand side. Both inlet valves were bent but no marks on the piston crown . And it looked like someone had attempted to straighten them previously !! - the bike was running ok apart from the gasket leaks, and the owner had the bike for about a year and had never had it apart.






Anyway, put it all back together and it runs lovely. God knows what had caused it .

Then another 1100 that kept running out of clutch adjustment ? clutch not slipping, just needing adjustment every few miles. So, out with the pushrod and thrust piston - the thrust piston has melted where the bearing sits, and the pushrod had broken. Which means the gearbox has to come out, as i couldn't remove the small section stuck in the diaphram spring.

Picture of the broken rod, and a normal pushrod



The fecked clutch thrust bearing -



And what it should look like =



And how they fit



All back together and running. Two unusual problems one after the other. What an interesting and fulfilled life i lead

 

[Geordie Steve]

I can sense the job satisfaction though... makes it all worthwhile.

I'm no expert, but those valve stems look bloody long... no wonder they bend?

 

[Tarka]

Fecking hell Steppers...looks and sounds like fun !


Do you think the bent valves may have been the result of the bike getting submerged in a failed fording trip,and hydraulic locking ???

 

[Steptoe]

Not sure which was the main cause of the pushrod/thrust bearing. I suspect the thrust bearing seized first, causing the pushrod to spin against the diaphram spring which caused the end of it to snap. Had the thrust bearings go on a few different models of BMW, the same bearing is used on K series bikes and later airheads, and it's a replacement on airheads from 1981, the original type no longer being available. The original type was a £5 fix "IF" the bearing ever failed. The type used now is a sealed unit costing £40 plus . And frequently needs replacing.

Being a smart arse ( and having the parts ), i've used the earlier type on my 1100 .

Here's the current type -



And the earlier 3 piece type with the roller bearing -





BMW have a bit of history making cock-ups on the thrust bearing design, the older Pre-81 bikes had a taper roler bearing, meaning that as it spun around, the outside was turning faster than the inside. Which meant the bearings squared off and stopped rolling, which meant the clutch pushrods snapped, frequently. Not helped by the pushrod having a cut out step in the middle, to hold a felt oil seal.

Parts of the earlier pre-81 bearing - which you can't change to the later type, without also changing input shafts, pushrods clutches and actuating arms .



Just thought i'd mention all this, as i'm having a teabreak and nothing else to do

 

[Ogmios]

yikes!
maybe we should have a GS version of this;
http://www.guzzitech.com/Shrapnel.html

good post Steptoe
~~
Og

 

[Steptoe]

I'm no expert, but those valve stems look bloody long... no wonder they bend?

As is usual on nearly every job i work on that needs parts, they changed the valve sizes in july 95. And the bike i was working on was made - - - - july 95

yikes!
maybe we should have a GS version of this;
http://www.guzzitech.com/Shrapnel.html

I've got my own gallery - i may take some pictures and post them when i get time

 

[GS TRV]

Dear me!! And there's me struggling over th ew/end to try and install my Stebel magnum

I guess you either have it or you don't.

 

[cookie]

yikes!
maybe we should have a GS version of this;
http://www.guzzitech.com/Shrapnel.html

good post Steptoe
~~
Og

ouch!

not seen that page before

 

[Bezzler]

Neil did you get my PM about brake pads or has it gone missing ????

Cheers
Terry