Timing marks I'm rather odd

itma · Post by **itma** » Sun Apr 24, 2011 2:00 pm

the hissing might well be a failing head gasket

aobp11 · Post by **aobp11** » Sun Apr 24, 2011 3:40 pm

I think to remember that Spriddler wanted to say that the inlet valve is open (not: opens) during part of the compression stroke and that's correct. When moreover the cam is one or two teeth too late this will cause breathing back through the carburettor.
Albert

thirdwheel · Post by **thirdwheel** » Sun Apr 24, 2011 8:25 pm

nope it's not the head gasket as I can mute it bt placing my hand over the carb like a trumpet and can vary the note. An old boy I met in a pub in the 70's told me he used to be able to have the head off his Rudge multi in the time it took a cup of tea to become cool enough to drink quickly. Wish the 18s was like that because it would be being peered at by now. I recon it takes under an hour to get off but at the moment I'm having little rides and enjoying it. Will sort it later though.

George

thirdwheel · Post by **thirdwheel** » Sun Aug 14, 2011 8:59 pm

Update
Found inlet valve seat was not concentric to guide - found by using engineers blue. I have had an oversize exhaust guide made and fitted as I could not find anyone willing to copper plate a new one to make it oversize. Had seats cut and gas tested with new valves, new valve springs, +60 rebore and new piston. The engineers I used are good but slow so had to buy a 16s to have fun on while the work was done. All back together and goodness I've compression now! I still think the valve timing is a bit out as it really does not tick over as it should - very lumpy and very much not like the 16s. I have a new carb and a rebuilt mag so I will have to get the dial guages out and check out the timing properly but at the moment I'm going to ride it. Oh are the 500 and 350 cams the same as I could compare the two sets I have or even swop them when the weather closes in again. Could I have scramble cams - my mate mentioned this on hearing my bike.

George

itma · Post by **itma** » Sun Aug 14, 2011 9:55 pm

scaramble cams are marked SH for your year of bike I doubt you have them.

500/ 350 cams are one and the same only different by the pinion marks, make sure you have not timed it as a 350 and check that the auto-advance id you have one is not sticky or binding.
Copperplating the guide would have been a waste of time anyway.

here's some guff re pinion marks.

Its in black and white so its racially correct.

http://i67.photobucket.com/albums/h314/ ... .jpgEdited by - itma on 14 Aug 2011 8:57:32 PM

Merlin · Post by **Merlin** » Sun Aug 14, 2011 10:38 pm

Its in black and white so its racially correct Not PC should read coloured and white.

thirdwheel · Post by **thirdwheel** » Sun Aug 14, 2011 11:09 pm

Many thanks ITMA for the link - I really do need to go back to first principals and time this engine using AMC published data as I think I have a bit of a mixture with only a "1" on the inlet and only a "2" on the exhaust. Adv/rtd is all ok and is manual. with weather like this I would rather be riding not spannering and I really do need to get hold of a lifting bench to make this kind of work easier.

Many thanks again
George

en7jos · Post by **en7jos** » Mon Aug 15, 2011 2:32 am

Now now children... play nicely!

These 'Oramorph Cocktails' that Mr Spriddler has been mixing up sound good though! Reminds me of the time we went to visit my old man in hospital one boxing day after his triple-heart-bypass. A bit surprised to see him so smiley and happy after such a major op, feeling on top of the world and ready to be discharged. Then we noticed the huge half-empty syringe driver at the side of the bed!

Hope you're feeling much better now anyway Neville.

itma · Post by **itma** » Mon Aug 15, 2011 2:08 pm

Bloody emigrant causing trouble Merlin

please re read carefully before sounding off

en7jos · Post by **en7jos** » Mon Aug 15, 2011 2:15 pm