Honda-SOHC

Does anyone have a set of mounting brackets for the original 4 exhaust system spare they would be willing to sell?

Just on my final stage of engine rebuild and about to put back Cam but I have some confusion/questions around how all this works. This is really about satisfying my curiosity more than anythinig else............

So you line up the 1.4 timing mark so pistons 1 and 4 are at TDC and then line up the marks on the cam - I get all that but this got me thinking -- cos as an engineer I like to understand how all this works so here's my confusion.

Lets say Pots 1 and 4 fire at TDC , crank then  rotates 180 on the bang stroke, then rotates another 180 on the exhaust stroke and 1 and 4 then get to TDC again at the end of the exhaust stroke. Now surely the 1 an4 points will open again and fire the plug again. I would have thought the crank needed to rotate 360 before firing 1 and 4 again.

Clearly I am missing something obvious here or dooes it fire again at the top of the exhaust stroke.

Looking forward to demystifying this !!!

I am a bit mystified 

Thanks
Probably a stupid question but i note the Roadrider is shown as a tubeless tyre do you have to fit tubes anyway on the honda rims

I will soon be looking to apply for an age related registration form my 1971 500 Four K0 that was imported from USA in 2015.

I have all the correct Nova paperwork etc but may be struggling struggling to get a proof of age document that DVLA will accept

. I contacted Honda in the USA who sent me the attached but DVLA said they need to know both Year AND Month of manufacture but the person I had on teh phone was pertty clueless.

Does anyone by any chance know if the attached would be acceptable as proof of age documentation, Honda USA are saying this is all they can provide.

Thanks all