Double Dog Dare on Compression releases

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hobot said:
I had look at shaft with a cut out method to press exhaust rocker down a tad.
Looks like its possible to do. Rocker arms stand above the cover gasket surface ~1/4" where the tallest part of rocker ach is. So shaft would have to cross rocker boxes about .8" below the top cover stud. Actuating lever would go rotate along side of head, lifting up sticking forward to press on valve then flopped forward to lay down almost vertical tucked in close to head for a tiddy device.
No oil passage on valve side of rocker so some metal could be removed if needed.

Main issue I ponder is if the two small studs and ridgidity of the rocker covers could take the spring force to hold valve open slightly and still seal or not break.
Space for shaft must be made, either just drilled through cover or by a half nip out of head and cover. Don't know how to seal shaft ports. Advice accepted.

Wonder if valve gap can be diddled to both lower kick force yet still start and run long enough to lower releases in time. May be able to kick engine over with the long duration over lapped cam, but don't think it'll be much help going by the starting efforts of racers with similar aggressive cams and CR.
Would have to start with too much gap to run then file and try file and try file and try till either works as hoped or becomes too hard to kick and start, ugh.
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The Husaberg (and the KTM since its a copy :)) one is only used to hold the valve (well actually both) open so you can push the engine just past TDC/compression and get a full intake/compression/fire from the kickstart . Im not sure how it would work with the twin, maybe it would run ok on one pot, allowing the exhaust to be held open on the second giving the required amount of time to close/flip lever. A second thought and Im not sure how it works but a 2cylinder yanmar marine engine has two compression release levers on the tappet cover, each two position, both pushed pully over and you can crank it by hand until its spinning fast then flick one to the intermediate position and it will fire, once it fires a coupleof times the other lever will also go to the intermediate position by itself, both positions lower the compression but it will run in the second position. To make it run properly flick both levers right across. Ill see if I can have alook at a manual for one this week and get back to you on it
 
I had a compression release on my 1950 BSA single 500. Never used it. Just pushed it over first TDC and went for it with gusto like the Commando. Or parked on a big hill at the Presidio of Monterey where I lived.

Dave
69S
 
Caught after dark in the wet knocked down by something to bottom of muddy valley with fairly injured kicking knee and breath knocked out, would want some relief.

Releases can work both way, one to get past TDC or spin enough can drop to run,
the other is able to start and run with release open, just not full power or release closes by itself. The marine engine report was the insight I'd hoped for to verify a slight valve lift type release can allow starting to run long enough to get full sealing.

Oil sealing may not be an issue in Peel if the exht sucker keeps insides lower than ambient. Would be good to install some sealing device to keep grit out, if I only knew a way. Could not crush down to change contact on rocker lift.
 
DogT said:
I had a compression release on my 1950 BSA single 500. Never used it. Just pushed it over first TDC and went for it with gusto like the Commando. Or parked on a big hill at the Presidio of Monterey where I lived.

Dave
69S
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Hi Dave

I mentioned on another string...my first Commando in '73 was a '72 750 combat roadster with 300miles from new. At the Palm Springs mountain station parking lot..very steep down hill, I was feeling lazy, so rolled it down that hill up to 40mph and dropped the clutch in 4th gear. It skidded to a stop. Maybe a compression release would have helped.

Na..if you're too old to kick start it, get an 850 MkIII and a big battery. :)
 
Actually roll start relief would be icing on the cake for me. Try to roll start on Gravel because something hung up the kick mechanism. Think stopping to remove a hazard in wet and muddy, not safe to let bike idle to dig into surface and little traction on kicker with mud lubed boot, a full compression roll off just puts once where the run off is flowing.

Do you know how to kick start a Combat with a dangling R knee by your self?
I do. Relief would of welcomed then and also a well sealed 920 10.5 CR.
 
illf8ed said:
Na..if you're too old to kick start it, get an 850 MkIII and a big battery. :)
Click to expand...

Good advice. That's what I've done, along with Dyno Dave's starter motor. Works just fine for us old geriatric cases.

Ken
 
Aw shucks, this young buck is holding back on portable compact air drive starter solution if releases ain't enough. All the good spots to mount electric starter is taken up already or reserved for the view beyond. Prefer to forgo the mass and expense of much of a battery or over pressured air tool.

Flick flick, kick kick, flick flick, zoom zoom.
or
Flick flick, Bezz Bezz, flick flick, zoom zoom.
Double Dog Dare on Compression releases
 
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