setting timing

[acidburn]

ok so a while back my friend explained to me "the easy way to time" but i forgot how the valves should go... from what i remember i have to do something along the lines of this.

open valve covers, turn rotor till exaust valve goes down up down up nothing nothing repeat?

then i take off my cam sprocket screws and turn untill pison is TDC


can anyone clear this up for me :D?

[rdlsz24]

You lost me there but if you download the manual for your trike it tells you how to do it step by step.

Rob

[acidburn]

iv read the manual like 100x it isnt very specific.. just says put piston TDC and line cam mark

umm ill try and be more clear..

basicly i need to know what motions the exaust valve should make before i take off cam sprocket screws and set piston TDC

[Lukeatc185]

i keep the valve cover on. turn the flywheel slowly until you see the intake valve open and close next time u see TDC apear on the flywheel is combustion stroke. line up the cam gear with the marker on the valve cover while the flywheel reads T in the peep hole, bolt it back together take the valve caps off if you have them if not i dont kno whow you will check this 100%, but as long as those markers line up and u see the T, there should be no valve open. u should be able to rock those arms 2 thousands of an inch.

[acidburn]

ok, intake valve is the one on the top of the engine correct?

and open means the valve goes up?

[Lukeatc185]

this a 2 stroke or 4 stroke?

[acidburn]

4stroke
81 atc200

[Dirtcrasher]

Apparently you have an odd manual.....

There are two TDC's and the "T" on the flywheel is your good buddy but YOU have to figure out which "TDC" you are at.

One is at the compression stroke, and one is at the end of the exhaust stroke and the beginning of the intake stroke.

Compression stroke - There is play in both rocker arms (unless things changed and they need to be backed off)

Exhaust stroke - Your exhaust valve JUST closed and Mr. intake is about to open and will have a lack of play in one or the other or both.

The EASIEST way to determine TDC on the compression stroke and ready to FIRE, is to open up a valve adj. cover and see where the cam lobes are. If they are completely opposite the rocker arms, you are at the compression stroke and your done - HOORAY!! If they are in contact with the rocker arms you are at TDC on the exhaust and intake stroke.

On an engine such as a 350X or 86/87 200X - the firing timing is fixed under your left ignition cover. YOU determine whether the cam goes in lobes up or lobes down depending on the cam/rocker arm design.

Putting the lobes up towards the rocker arms on the TDC compression stroke will cause it to be 180 degrees out because it will be firing at the end of the 4 strokes and NOT at the compression stroke when your fuel and air mix are being compressed.

Putting the lobes 180 degrees away or DOWN from the rocker arms at TDC is correct because it is at the compression stroke.

On other engines, such as the 185, 200S, ES or 85 qand under 200X engines; The firing or ignition timing is done at the camshaft and under the access cover. Thats where you find the pulse generator and the weights that advance the timing based on the egines RPM's. On these engines with the flywheel at "T", you need to face the cam away from the rocker arms or it will fire at the wrong TDC even if your on "T".

4 Strokes guys - 2 at TDC and 2 at BDC.

Some of you may care less how a 4 stroke works - why, when, wher and how. But BELIEVE ME, having a clear understanding of how it operates and what each stroke does with it's relationship from the crank to the cam, will make you soooooooooooo much better mechanic with confidence :D Piece of cake.

Does that make sense to you guys, I sure hope so :D

[acidburn]

i understood that somewhat but im no mechanic what do u mean when u say
"s to open up a valve adj. cover and see where the cam lobes are. If they are completely opposite the rocker arms"

what and where are "rocker arms"

[Lukeatc185]

they are whats attached to the valve cover, they get pushed by your camshaft then open your valves.

[Dirtcrasher]

Get some help, get someone who understands how this all works or it's just gonna cost you money and no trike to ride.

If you don't know what a rocker arm is, then you shouldn't be opening up an engine without some help.

I mean that in a nice way, there is nothing wrong with not understanding what every component does and how they work.

Believe me, spending a few hours on the internet searching "how does a four stroke work" will make you a much better and more confident mechanic.

I'm gonna sit down soon and start a thread solely to help people understand what happens and when in a 4 stroke engine. There are FAR too many guys that end up bending valves and ruining engines merely because they don't understand whats going on in there.......