my 45" was running once, when it was, I would ride for about twenty minutes and would lose compression. I could push kick starter with my hand. Wait for bout hour, let it totally cool down and then it would be back to normal, then repeat all over again. I tore down top end, redid valves put total seal piston rings in and new heads. I kick it over to check compression, when I noticed the exhaust port was sucking in. took heads off, put new cams in, put back together. still sucking in at exhaust. Is this supposed to be? I started my 02 road king put my hand over exhaust and kinda felt slight suction/ exhausting alternately. So I'm wondering should I complete putting 45" together or is there an issue with this exhaust suction. Only thing I can think of is I have cams out by one tooth. Which I find hard to believe because I quadruple checked cams before putting cover on. Am I looking too much into this? Does anyone have any input on this subject? Any ideas welcomed.

 

the first problem was it was over heating and lost the piston seal

it might have been an intake leak or a rubber tipped float valve - stainless is the only one to use comes as a kit 2 pieces

second question -- and yes while the exhaust valve is open normally its blowing out as the piston is moving up ( but on over lap the valve is open as the piston has not come to bottom dead center yet (( its still moving down )) so yes you can get a suction at the exact right spot )

 

Sounds logical, thanks for input.