Scrambler

[graeme]

Hello Wolf,

A little piece of alloy to make my boots last a lot longer.
And a Mike’s XS reed breather (650 Yamaha) helps keep pressure out of the crank case.

Regards
Graeme

[Wolf]

...I was too fast thinking the oil problem has vanished (maybe it's a little better but not gone). This morning arriving at work it leaked again. I still assume that the front left-hand stud boring interferes with the boring of the rocker spindle - is there a known remedy for this?
Cheers
Wolf

[Dan C]

Nice bike Graeme! Whats its like poking along behind a mob of sheep....?

[graeme]

Wolf,
I have a bare (empty) 450 Scrambler head.
I looked and the through bolts don't open to the rocker spindles. Unlike Desmo heads.
Desmo rocker spindles use an O ring to seal the rocker spindles from the through bolts.
Through bolts ? I assume you are talking about the 4 bolts that hold the head and cylinder to the cases ?
Do your Through bolts have the thin shim/seal under the washer, under the bolt head ?

Could it be a porous head casting ? I have found porous cylinder castings in the past.
Also, '77 Darmah front head leaked (what looked like dirty oil) on the floor under the front head/cylinder joint. This turned out to be a not flat joint in the head where it sat on the cylinder sleeve.
Lapped the head with an old cast iron sleeve and valve grind paste, checked with blue until it was flat.,,,, no more leaks.
That took me a long while to figure out the cause.
Wash it off with petrol or some fluid that doesn't leave any residue and puff talcum powder over it, short ride and you will see exactly where the leak is.
Oil can travel a long way with a hot engine and wind. As you know
Good Luck.

Dan,
Sheep and the Scrambler is like herding cats, much easier on foot.

Regards
Graeme

[Wolf]

Hi Graeme,

well - I think the oil-situation improved a lot. Now it is only a small drop (this morning there was no oil leaking) and not a small puddle any more.

Nigel mentioned that there is sometimes a problem with the 450-heads. He mentioned breeches between spindle hole and bolt holes.
Maybe it is the case with my motor.

I’ve acquired the bike last year, the former owner told me of the oil leak problem which he assumed to be originated from the leaking O-Ring. I think this is not the case, I’ve replaced the O-Ring and it’s still leaking – now having the reed valve installed the problem almost gone is maybe a sign that it is not pressurized oil but a low-pressure oil problem.

I consider taking the engine apart this winter to clean the sludge traps and maybe I will get some insights in the cylinder head hole interference situation.

My through bolts don't have thin shim/seal under the washer of the bolt head.

Cheers

Wolf