Short legged dutch riders ask Jos den Ouden for longer kick start levers.I got them in mine Blackshadow but very hard to start specialy when you are short legged like me.
Regards, Jan van Drenth
Short legged dutch riders ask Jos den Ouden for longer kick start levers.I got them in mine Blackshadow but very hard to start specialy when you are short legged like me.
Regards, Jan van Drenth
Hello Eddy, Is there an easy way to work out the Balance Factor, I have read the Higgins bit and checked a few Web sites, But I am lost on the Maths side of it.The link I put in in post #7 above takes you to the relevant article but the paragraph referred to isn't on page #4 but earlier and says:
"A number of years ago I visited Bob Dunn, and when we talked about balancing he told me he had recently done a check on a number of engines, finding that those having a balance factor around 50 per cent were good, 45 per cent were OK, at 40 per cent they began to vibrate, and down to 30 per cent they were really bad. Some people running Norvins claim that a 60 per cent factor gives them a smooth engine. Since then I have aimed at 50 per cent for my engines, and Jindivik is currently running 50 per cent and The Heap 53 per cent. I cannot claim that they are noticeably better than when they were at 46 per cent but it seems that it is not very critical, so if your engine comes out at 46 per cent to 50 per cent you should be all right. "
Dear Bill,Hello Eddy, Is there an easy way to work out the Balance Factor, I have read the Higgins bit and checked a few Web sites, But I am lost on the Maths side of it.
I want to do a Comet soon. Cheers Bill.
Hey, Bill,Hello Eddy, Is there an easy way to work out the Balance Factor, I have read the Higgins bit and checked a few Web sites, But I am lost on the Maths side of it.
I want to do a Comet soon. Cheers Bill.
Thanks I will go 60' but not good with sums cheers billHey, Bill,
the Prof. is talking abt his twin engines; you r looking for Comet values. Do not mix up twins and singles - they
are different also in balance factor. Best u can do, is to read, what Phil Irving wrote abt the subject in his book:
"Motorcycle Engineering". U may surely find someone, who copies or scans the relevant pages for u.
cheers,
the 7.3 cr pistons are 8:1's with the piston crowns turned off i believe they fail after a large mileage with hairline cracks across the crowns i have seen these after the event in Bury. There is also an issue with the gudgeon pin circlips which move with the usual catastrophic consequences on the pin milling a groove in the bore . Mahle via the manufacturers in england issued a warning with pictures of such failures. and recommend that the circlips be fitted with the gap horizontally or vertically positioned. to prevent this happening . they accuse the user of over revving the motor for this failure . Sounds like a design fault to me. if the pistons are not scuffed and the ring lands are not worn you could treat it to some new ringsI have decided to check the bores as it's still on standard with way past 100,000 miles on the clock(s).
So what is the advice regarding the piston choice?
7.3 :1, or 8:1?
It's a Touring Rapide so performance not necessary.
Are the modern pistons the same weight, so I can I avoid having to rebalance the crank?
Anything else I need to know?
Thanks,
Chris.