Been busy carrying out some work on an Egli with genuine Shadow engine........primarily set up as a race bike methinks, but has lights and horn.......Had a pair of 38 mm Gardeners.........1200 cc TPV heads/barrels.......Tri spark twin plug ignition. Ignition was out 180 degrees so there was my starting point........Gardeners too difficult to tune for a road engine.......removed and installed a new set of pumper 40 mm Dellortos' and made up some manifolds to suit.......Great all looking good so far.......Engine would run actually quite well, but very difficult to start.......tried different starting techniques but nothing really jumping out to make it better........It did have an oil leak at the timing cover........I suspected that it might have some big cams that were making the starting an issue....... removed the cover, naturally 2 of the spindles were loose and no seal at all on the valve lifter mech.......At this point I noticed the cam locating slots were out on both cams by 3 teeth retarded.........Hmmmm........Fixed all within the chest, re set the cams to bring the slots in line with the barrel centers........re set the ignition to 28 full advance, reassembled all parts and timing cover.......filled the oil tank with 15 w 40 oil, bled the feed line........plugs and caps on, fuel on opened the throttle fully twice, started 1st kick.........Love to know who was the last person to work on this bike........The reason I felt the engine may have had big cams in it was........when it was running before i removed the cover, it had quite a lot of reversion visual from the front carby........the cams were just Mk 2 Lightning cams so nothing crazy there........just retarded by 45 degrees.......So nice to be able to give the bike back to the owner knowing it will start ok and not be a total pig........Sometimes you have to look further than you think especially if the bike has an unknown or unusual history........I can give my right leg a break now..........Cheers.
had similar symptoms/problem with my C rapide on first starting attempt.
bikes been sitting for the better part of 30 years with the usual crud settling down everywhere. cleaned all up, temporarily replaced oil lines (scavange line to heads literally snapped in half!) with 8mm fuel lines and clamps, fresh oil and give it a go.
I think it was a good move to have the windows replaced with double glazing, as the amount of backfire and banging from the exhaust would've clearly blown the windows out... I had ringing ears for the better part of the evening, blimey!
anyway: it was a terribly hard to start it and it only ran on the front cilinder, and a pissed-off dragon breathing out the rear carb (with the frequent banging in the pipe). this being my first old big twin it sure did test my stamina incl valve lifter (I come from less older Ducati bevel background and Royal Enfield).
it occurred to me that whilst priming I could clearly hear the front suck air, but the rear was sucking AND blowing. that's when I thought hang on, is that reversion?
so popped the thing chest and sure enough: the rear cam was retarded 2 teeth and the from advanced 1 tooth. bike mechanical history 101% unknown. using the data in the literature the single dot on the rear cam should be 159degrees clockwise from the slot, compared to the actual gear mesh showed the 2 teeth retard and 1 tooth advance, without even measuring valve lift whatever.
got the lot sorted as good as I could get it, without pressing out the cams from the gears, shifting the half-time pinion about, ignoring the marks on the cams (they're off-spec too!) this time using a degree wheel and dial gauge for the 0.13mm/0.005" valve lift) it starts easier and runs much smoother than before (but still bootcamp stamina starting), no fire-breathing dragons, only bangs now and then when restarting on a hot engine. full advance is set 38degrees BTDC rear cylinder as per instructions.
current nicks are leaking rear koni damper (Special "D" 76C 1083?), oil oozing from the ratchet shaft bearing, oil thrown out form the dynamo boss and rather lean combustions from the AMAL 389/689 1-5/32" with 250 mains.
stock 998 with (I assume) 7:1, Mk1 cams (I'm told based on pics), 21/46 gearing, 19" front 18" rear, and as a bonus the aluminium BS brake plates up front (with integrated into casting air scoops, not screwed on scoops!)
sorry to hi-jack your thread, got carried away there.
the essence is: I had cams out-of-spec few teeth with backfire/reversion.
putting them back to close as possible timing made a world of difference.