Date: Wed, 10 Jun 1998 12:36:32 +1000
From: Chris Ghent
RickT wrote:
>Since there appears to be a rather noticeable oil leak from the region
of
>the primary cover, I imagine that removal and seal/gasket replacement
will
>be my next order of business. I'll take a careful look at the
alternator
>and anything else that might be responsible for the noise.
>Rick
Not sure about the MKIII but on any other Commando the primary case leaks from the pathetic seal around the mainshaft behind the clutch. Mine leaks when first filled and then stops. If you overfill at all it will come out this seal. It runs down the outside of the inner case and then forward along
the seam at the bottom between the inner and outer and then drips off directly in line with the crank. Many people jump to the logical conclusion that as it runs along the seam it is coming from the seam. And it still may be the case with yours. But experience says not.
The seal is a felt ring which people seem to have trouble fitting. My method is to get two small screwdrivers, pinch the outer edge of the ring in between them and stuff it in. Takes about five minutes as it's a tight fit.
>The bike appears to have approx. 30,000 mi. on it. Are the symptoms
that I
>have described caused by worn carb slides.
Seems reasonable to me. One bloke in our club replaces his every 9000 miles.
Something you did not mention doing was checking the flanges. They all bow. This causes air leaks and heating the bike may cause them to leak more. (I suspect for the same reason that you heat bearings to get them on... the ID expands) I'm told spraying petrol on the joins will confirm an air leak as the bike will pick up idle speed for a second if you spray over a leak.
What I do is use the time honoured abrasion paper on a glass plate method. Both ends of the manifold, the carb exit and the float bowl all need attention. The metal around the bolt holes on the head can lift also. Everyone says the way to avoid it happening again is not to do them up too tight . Hard to judge.
Something else to check is that the main jets are screwed in tight. They can unwind and cause weird problems. The bike will usually idle but pop and bang when running faster. It is possible to check this by undoing the drain plugs and seeing if either of the jets wobble.
Never compare cold idle responses on the engine to when the bike is hot. All the time I ever spent on carbs with a cold engine was wasted. Take it for a fifteen minute ride. They will also idle differently if the air is denser, if the day is warmer or cooler, if you dress to the right or left, on rainy Tuesdays, and if you whistle Dixie backwards. I have made myself a rule of thumb that I never adjust the idle once I have identified it as a problem without listening to it for a couple of weeks of daily riding. This prevents me from "chasing" the idle all over the show. In spite of the inherent problems with Amals this rant reveals I am still Amal retentive. And don't completely dismiss the possibility that at least part of your problem may be electrical. Having said all that, I recall the frustration of my own attempts to tune my bike over a long period of time and the utter lack of predictable or repeatable results from worn slides.
When I bought my Commando I resisted advice to put a Boyer on it, to buy new carb bodies, replace the chains and tyres, and to put a decent seal in the tacho drive. All these things I would now do as a matter of course if I bought another one. But will I? Don't they say, ...a man with two women has no heart, but a man with two motorcycles has no soul...
You say the problems keep coming. And they will. In the end it is the owner who becomes reliable.
Hope this helps. Sure was cathartic for me. Just trying to save you from summer on a Triumph, the only bike I've ever found where the brand name was an oxymoron.
Regards
Chris Ghent
"they all do that"