I know it's a little off the two wheel track and it's possible that it's been mentioned before, but ……….. this has to be the ultimate in fun and even I might be able to use it!
https://www.youtube.com/watch?v=qSMWEd54NcA
I know it's a little off the two wheel track and it's possible that it's been mentioned before, but ……….. this has to be the ultimate in fun and even I might be able to use it!
https://www.youtube.com/watch?v=qSMWEd54NcA
Strokers Galore!
Just found out about these. Most outboards have reed valves into the bottom of the crankcase but Mr Martin thought different, apparently. I've seen automatic inlet valve two strokes in museums and books but these are timed by eccentrics on the crank.
https://www.joeoutboard.com/manuals/martin-manuals.html
[QUOTE=guyhockley;......these are timed by eccentrics on the crank.[/QUOTE]
That's keeping it simple, a bit more work to change the timing, but!
Cheers, Daryl.
Older outboards with bush main bearings often don't have any additional crank seals and I think the crank is running directly in the crank case as a centre bearing. The cams are either side of that.
Interesting that it's a horizontally split case when the Japanese hadn't invented them, yet!
When you look at the patent pic it looks as if it follows common auto practice of separate sump alhough in this case its half the crankcase
I read the other day that Suzuki and Kawasaki never line bored the twins and threes main bearings as one operation.
Where as Yamaaha did and for that reason. Yamaha lab seals dont last in these other bikes without correction of this.
It turns out the rubbers seals are much more forgiving for potential misalignment. Made sense to me.
I think the YR3 was the first Yamaha with horizontal split cases about 1969
There was a hilarious story in one of the UK newspapers, years ago, about the decline of the British bike industry. The writer had obviously misunderstood what he had been told. He said that British bikes had vertically split petrol tanks that always leaked and the Japanese had introduced horizontally split tanks to keep the stuff in.
There was or is a website about a bloke racing an early Suzuki twin. At one point he had the cases line-bored to take larger, Yamaha main bearings. If I remember right the poor machinist had a bit of bother because the cast in iron/steel inserts were all over the place.
Not quite how I remembered...
http://www.t20suzuki.com/racing.htm#TZcrank
9 valve, surely?
There are currently 4 users browsing this thread. (0 members and 4 guests)
Bookmarks