Have a 1984 Honda GL1200 Aspencade Gold Wing that Hammers pretty hard when I start it. What will fix this please?

Question edited for full 'year make model'.
Question moved the correct category.

It really depends where it is coming from. This is a 1200cc, 4 cylinder car engine in a bike frame. If it is coming from the bottom it is bad news as that is where the crankshaft bearings and connecting rods are. If it disappears when it warms up, all well and good, but not perfect and it will only get worse.. It is more likely coming from the top of the engine because that area pretty much fully drains of oil after turning off, and it is the last to get oil when you start up. Make sure your oil is clean and use full synthetic oil if possible. I would also add some STP Oil Treatment or MolySlip. This is made to lubricate better and stick to surfaces. You can fashion a stethoscope to pinpoint the sound by sticking a piece of 1/4" polythene pipe in you ear and listen to top and bottom end.

https://www.google.com/search?q=1984+1200+aspencade%2C+knocking+on+start+up

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