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mjwillie

99 TRX FW Valve setting quesion

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Hello all.....Brand new to the site......Been fun reading other peoples problems

My problem is I am installing a new Head/Cam/Cover on a 99 TRXFW. Before you ask I do have a manual......The book states "line up the "T" mark and adjust.......Make sure you are on the compression stroke"........If the cam has been removed how can you tell if you are on the compression stroke and not on the exhaust stroke?

My worry is I will install everything and it will be 180 out.....Can anyone help me?

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???? That is a good question??? With the cam out are your valves still moving up and down when you turn the motor? On the compression stroke all the valves will be closed.

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Of course the valves are not moving the cam is out and so are the rockers.....The question is all in the ignition system......and figuring out compression vs exhaust so that we send a spark at the right time

A thought is that the coil opens on both the exhaust and the compression stroke allowing a spark every 360 degrees......But I can't find that in my book

Thanks for the response

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Bot, do you feel silly about asking that question?:hitself: Don't be too hard on yourself though, we all have brainfarts.

If the cam is out of the motor it won't matter, TDC is TDC, the position of the cam is what determines if you are on the compression or exhaust stroke. You are correct about the ignition, it runs off the crank and sparks each time the crank turns. This is called a wasted spark ignition. The only way the ignition system can tell the differece between different strokes is to run it off the cam instead of the crank. Just make sure all your marks line up when you put it back together.

Edited by DirtDemon

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Don't you hate when you look into stuff to much. I started to get all complex in my mind when the answer is obvious. I need to remember to think simple first.

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Don't you hate when you look into stuff to much. I started to get all complex in my mind when the answer is obvious. I need to remember to think simple first.

I understand completely, I do that all the time. I wrack my brain trying to figure out some simple elementary thing when the answer is right in front of my eyes.

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I understand completely, I do that all the time. I wrack my brain trying to figure out some simple elementary thing when the answer is right in front of my eyes.

i def. know where your coming from lol spent an hour one day screwing w/ my wifes 4 wheeler before i noticed that she had turned the gas to reserve oops! ya so it wont start cuz you ran the reserve tank out ......so ya uhmmmmmm im going to go smash my face against the nearest tree for a bit lol.

we all do it.

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i def. know where your coming from lol spent an hour one day screwing w/ my wifes 4 wheeler before i noticed that she had turned the gas to reserve oops! ya so it wont start cuz you ran the reserve tank out ......so ya uhmmmmmm im going to go smash my face against the nearest tree for a bit lol.

we all do it.

LMAO. yep thats about the feeling!

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with the cam out the compression stroke will be with the piston at the top of the cylinder that is when it compresses and causes the fire. You want the piston at the top of the cylinder to be on the top of the compression stroke.

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With the cam out there is no compression stroke or exhaust stroke, it is the position of the cam that determines which stroke you are on.

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