ET: Engine (Twin) Inspection Caps
- Thread starter moto8500
- Start date
Some combinations of caps/ pushrod lengths and tappets cause the tappet to foul the inside of the caps at full lift as you unscrew each inspection cap. Therefore it is safest to turn each cylinder to T.D.C. compression before removing the caps. Also look for a tell- tale small deposit of oil inside the cap which tells you everything is getting oil. What type of material are the gaskets? I get leaks most places, but never there.
On some of the early engines, HRD, maybe also later, but not sure, you were unable to unscrew the valve cap fully if the valve was lifted, so advisable to remove the caps when each cylinder is on the compression stroke.
Sorry I beat you to it, Mr. Holmes. You are right, the interior machining of the caps was changed and it is mentioned in "Know Thy Beast"; but more importantly there are more permutations of barrel height, pushrod length, rocker lift ratio and tappet design than were ever dreamed of in the philosophy of the original designers. With many, if not all machines the dictum "prove all things, hold fast to those which are true" is a wise starting point.
Thanks for the replies and the advice has freed up one of the inspection caps which was stiff to turn.
They are fibre washers but on closer inspection the area immediately below the washer was dry with it becoming oily a few millimeters away so attention turned elsewhere and I discovered the castellated nut holding the pushrod tube had vibrated loose so oil was coming down the thread and while I was riding being blown around the bottom of the inspection cap where it collected and dripped finally finding it's way onto the silencer.
I am yet to take the Shadow for a test drive but I am pretty sure that was the issue.
They are fibre washers but on closer inspection the area immediately below the washer was dry with it becoming oily a few millimeters away so attention turned elsewhere and I discovered the castellated nut holding the pushrod tube had vibrated loose so oil was coming down the thread and while I was riding being blown around the bottom of the inspection cap where it collected and dripped finally finding it's way onto the silencer.
I am yet to take the Shadow for a test drive but I am pretty sure that was the issue.
Fiber washers are stoneage for sealing duties on bikes. They need high torque for good sealing as they are not rubberlike, so bad for uneven or rough faces. Next problem is they can come loose after some time and vibration loads so again no good . Better get o-rings plus alu or ss washers around these so you can tighten down the caps and the lot is shakeproof as well with the o-ring inside. I think Dowty seals is the household name in UK with same idea ??
Vic
Vic
Stoneage or not, for caps they seem to work. Coming loose is not something I have found, their only draw back is the cost because you should never use them twice, once oil has shaken hands with them and the cap has been takenoff just once its time for a new one.
Gotta love this Club/Forum
One guy says never
Next guy says only once
Next guy says --- I've had a set on for some 60K miles, on and off many times, never had one come loose never had one leak, and you're looking at a guy who has probably 70 or 80 in stock so could change them every month for a long time!
One guy says never
Next guy says only once
Next guy says --- I've had a set on for some 60K miles, on and off many times, never had one come loose never had one leak, and you're looking at a guy who has probably 70 or 80 in stock so could change them every month for a long time!
Ask one Vincent owner and you will get a dozen answers.