hey there and thank you in advance!!
i need some help!! i was driving my 88 hijet jumbo with the 550cc 4spd after washing the motor down and it was running fine all the sudden was like it droped a cylinder and she started to spit and sputter and died tried to start it a few times to no avail Sad changed the plugs and nothing still.

i have ngk bpr6es plugs in it thats what had crossed over to it.
i am alslo looking for any and all info i can get on the 550 motor in the unit along with cross over parts like air filter etc.

i did some work on it today i did a compression check today its 150psi ish give or take 5 across the 3 cyl but it seem so have a weak spark. pleanty fuel as well. any ideas?