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-   -   THC said It's my fault (https://www.hdforums.com/forum/evo/1044494-thc-said-its-my-fault.html)

WP50 May 3, 2015 09:01 AM

THC said It's my fault
 
Ok in shooting the bull with THC about him putting his basket case back together. The cam timing marks came up and I mentioned I thought the crank had to be set at #1 TDC. Well this got him thinking (yea my bad) and he went to cking the FSM. He called me back and said there was no mention of doing so in either manual he has. I went to reading in my 97 FLT manual and I didn't find it mentioned either.

I read Spanners sticky about Kees bike and found no TDC reference there
Other than lining the timing marks up before taking things apart which THC's bike being a basket case he doesn't know if that was done.

I may have reverted to my auto background. Again my bad :icon_nut:

Is it because of the 3 timing marks used that might make it unnecessary to have TDC set on #1 or atleast one of the 2 cylinders?????

Thanks for your time folks WP

lionsm13 May 3, 2015 09:06 AM

Smokin' too much?

Owtlaw May 3, 2015 09:12 AM


Originally Posted by WP50 (Post 13980285)
Ok in shooting the bull with THC about him putting his basket case back together. The cam timing marks came up and I mentioned I thought the crank had to be set at #1 TDC. Well this got him thinking (yea my bad) and he went to cking the FSM. He called me back and said there was no mention of doing so in either manual he has. I went to reading in my 97 FLT manual and I didn't find it mentioned either.

I read Spanners sticky about Kees bike and found no TDC reference there
Other than lining the timing marks up before taking things apart which THC's bike being a basket case he doesn't know if that was done.

I may have reverted to my auto background. Again my bad :icon_nut:

Is it because of the 3 timing marks used that might make it unnecessary to have TDC set on #1 or atleast one of the 2 cylinders?????

Thanks for your time folks WP

I was over there yesterday and pretty much asked the same question. Whether the point where the timing marks line up on the pinion and cam gear is TDC. Checked the timing hole, and the answer is no. I got to thinking about it, and there's really no reason to tie the cam timing marks to the ignition timing or TDC, and apparently it's not. Cam timing marks can be made at any point in the gear relation, as long as it's consistent.

Edit: The overhead cams in my Suzuki, WERE indexed at TDC on the front cylinder. A necessary reference point when you have chain driven cams and can't see the pinion gear at that point anyway.

WP50 May 3, 2015 09:31 AM


Originally Posted by lionsm13 (Post 13980302)
Smokin' too much?

Umm Some Crown may have been involved :icon_crackup:


WP

WP50 May 3, 2015 09:35 AM

Outlaw
A friend was over(2 yrs ago) when we put mine back together, he's a HD tech.
I flat can't remember if we did or did not set things up on TDC.

I'd bet money we did though.
If I was in the middle of doing this I'd be asking too.

WP


Ahhh Both connecting rods are on the same journal, well one is just a little lower best I remember.

grbrown May 3, 2015 10:41 AM

The crankshaft timing gear is keyed onto the crankshaft and the cam is the only other gear. With the pushrods removed, which is inevitable, we are essentially building up the engine from first principles, after installing the cam with the marks aligned. So it doesn't matter where the pistons are, as the timing marks are the beginning and end of the build process!

Hope that helps.

johnjzjz May 3, 2015 10:48 AM

take out the two plugs - with the rear tire up in the air turn the rear wheel counter clockwise - with a plastic tube - straw - in the front cylinder rotate the motor with the wheel till the straw tops out ( move the wheel back and forth to get the center look in the timing hole that that is the mark for TDC -- BUT it still might be on overlap sooooo - look into the rear plug hole you will see the intake valve open a bit if not look in the front plug hole for a open valve - you could also use a length of 3/8 hose and put it over the sparkplug hole and blow into it / if it blows right through in the rear plug hole you are on front TDC compression stroke - Then set your timing static location right in the center spot ( little light on ignition ) of the mark in the center of the timing plug hole - your good to go

it is different if you have a stock ignition i did not read all of this - if so turn it to the center and use a timing light to confirm

some pinion gears look as if they have more then one mark on them but if it was runing and that was not removed or moved then forget that idea

WP50 May 3, 2015 12:59 PM


Originally Posted by grbrown (Post 13980534)
The crankshaft timing gear is keyed onto the crankshaft and the cam is the only other gear. With the pushrods removed, which is inevitable, we are essentially building up the engine from first principles, after installing the cam with the marks aligned. So it doesn't matter where the pistons are, as the timing marks are the beginning and end of the build process!

Hope that helps.

Yes Sir it does Thank You

WP

WP50 May 3, 2015 01:04 PM


Originally Posted by johnjzjz (Post 13980550)

some pinion gears look as if they have more then one mark on them but if it was runing and that was not removed or moved then forget that idea

These 2 points were what took our conversation in this direction.
No idea how things were took apart or the position of things now. Basket case

Thank You Sir

WP

Spanners39 May 5, 2015 05:34 AM


Originally Posted by grbrown (Post 13980534)
The crankshaft timing gear is keyed onto the crankshaft and the cam is the only other gear. With the pushrods removed, which is inevitable, we are essentially building up the engine from first principles, after installing the cam with the marks aligned. So it doesn't matter where the pistons are, as the timing marks are the beginning and end of the build process!

Hope that helps.

.......is the correct answer....did y'all know that some motors are not timed at TDC at all when building them?

Nissan Chain drive 4 cylinder car motors are set with all the pistons around halfway up the bore, this is so you can bolt the cams into the head without bending valves.

Yeah, useless trivial facts make the world go around.

Moral of the tale....believe in the timing marks, ignore what is going on with the pistons.


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