Homda trail 70 timing?

Question

new top end cams were out points are opening when its at top dead center,plugs are firing,,getting gas to the carb, jets are open..timing marks are ligned up? still wont run?

if your setting the timing marks do you put it at top dead center? and then lign up the marks? were do you start whne setting the timing on the gears,,,what else would keep it from running? spark,gas,compression.= run? point gap is set,,help!!

Answer 1

Oh man...

Well, I can't find anything really useful on the cam timing.

Which, I think, is your problem.

The points should actually open, like, oh, 6 degrees or so before TDC on the compression stroke. But the flywheel is marked, isn't it, with a T for "top" and an F for "fire", so you don't need to know the actual degrees, just use the F.

Now an old trick I used to use, back when I had points to set, and when nearly everyone smoked cigarettes, was to take a piece of cellophane from a cigarette pack, pry the points open and put the cellophane in there, and tug on it a bit as you turn the flywheel forward; and as it passes the appointed mark the cellophane will slip out. See, cellophane was really thin and didn't stretch; it would rather tear. You can find similar stuff wrapped around CDs and DVDs these days. Oh, and always set the gap first.

At TDC on the exhaust stroke, both valves should actually be open a bit. So the cam will be pushing on the valves and there won't be any lash. At TDC on the compression stroke the valves will be closed and you'll be able to wiggle them. That's how you know what stroke you're on.

I really don't know 100%, but I think that the mark on the cam gear and the T on the flywheel should point directly at each other, at TDC, on the compression stroke. It has been a while. If you had the cam gear pointed the other way it may be firing 180 degrees off.

I found a cool web site though, where you should be able to find someone sypathetic to your cause... see the "sources" list.

good luck and happy "Trails"

Answer 2

i am guessing that you are out of time. if you have checked it and double checked it then you will have to take it to a shop. take it with the flywheel and cam gear exposed and they will be able to tell you if it is correct in about 2 minutes.