Can i ride my motorcycle from tucson to phoenix on 120 psi cylinder compression?

Question

Ok so my motorcycle - 1978 Yamaha XS400 2-E - has about 120 psi compression on both cylinders. Both cylinders fire equally.

i just installed new ignition coils, ignition wires + caps and plugs, carburetor rebuild and new diaphragms. Changed the oil and oil filter. Bike is filled with oil quite well.

The bike is running great and i have taken it up to 70mph without any trouble, but i do know that 120 psi is considered low. (i only did the dry compression test by the way, never tried wet test...) Also starts on first kick every morning, every day, any time no problem

I want to drive the bike to phoenix from tucson arizona which is a 2 hour and 30 minute drive if i take the back road instead of the highway with an average speed of 60 mph. (I thought id take the back roads because Ive never driven that far and i want my first long distance drive to be safe...)

So my question is, will my bike be able to handle that long of a drive on 120 psi? And are there any other consumables that i should replace on the bike that might go bad due to the bike being run for too long?

Answer 1

Compression at 120 is fine, however, thats not what you really need to be concerned about. IF compression is an issue, the issue would be that they are both within 10% of each other.

Answer 2

You seem a bit fixated about the compression. Forget about it. The bike starts and runs well. It will do a couple of hours easily.



"And are there any other consumables that i should replace on the bike that might go bad due to the bike being run for too long?"



Not really. It all depends on the condition of the "consumables" when you leave. Just do your usual checks (tire pressure, chain condition, oil level etc) before you leave. If your chain is nearly stuffed, then expect it to fail on a trip. If your oil is very low, then expect the engine to suffer. Just common sense really

Answer 3

when checking compresion the actual factor is the differance in pounds between cylinders.If they are within 3 to 5 pounds of each other you are OK. It sounds OK to me I make that ride all the time in about an hour and a half you must ride or drive slow? Its only about 90 miles dude.

Answer 4

Go for it! I rode a Honda 350 from California to Colorado and back, and a while later from Illinois to Colorado. I rode at 65 to 70 mph. Your bike can handle those speeds.

Answer 5

You just need to do some short shake out trips to cover all the servicing you have done. Then you are away.....