Cam Orientation

Bigrider · 02-26-2014, 10:32 AM

I recently replaced the head gasket. I took note of the orientation of the cam lines on the right side of the engine, white mark facing front, but failed to note if the engine was in compression or exhaust mode. I then inadvertently moved the crank to attach the cam chain. Now when I try to start, it cranks but won't start. Don't know if I have the cam 180% off or just a carb problem. Question. With the engine at TDC on compress stroke, which way should the white mark on the cam be facing (front or rear)? Also, I tried hand turning the crank to see when the spark plug fired but it only fires when I use the electric start. Is there a method using a pencil light probe to check when the circuit is firing. This would also help me understand which way to orient the cam. Thanks for any help
Dave H
San Antonio, TX

raul10141964 · 02-26-2014, 10:58 AM

If you set the crank an the cam marks by the service manual will be correct

Bigrider · 02-26-2014, 11:19 AM

If I read, and remember correctly, the manual states putting the engine at TDC with the white mark facing the intake side. It didn't state whether the engine was on compression or exhaust. I would assume it would be on compression, but as stated the engine won't start so I just want to verify it needed to be "on compression".
Dave H

Water Warrior 2 · 02-26-2014, 11:33 AM

If memory serves me correctly TDC refers to the compression stroke.

Did you prime the carb before trying to start the bike? Just a thought.

raul10141964 · 02-26-2014, 11:53 AM

TDC (top dead center) refers to the position of the piston, the engine reach TDC on compression stroke an on exhaust stroke.
if you set the timing marks correctly the came time will bi OK

Water Warrior 2 · 02-26-2014, 04:18 PM

Quote:

Originally Posted by raul10141964

TDC (top dead center) refers to the position of the piston, the engine reach TDC on compression stroke an on exhaust stroke.
if you set the timing marks correctly the came time will bi OK

To set the timing I believe the engine should be at the top of a compression stroke.

raul10141964 · 02-26-2014, 04:40 PM

if the crank is on TDC and the cam is on it's timing mark, is the compression stroke

Goose51683 · 02-26-2014, 07:23 PM

Water warrior- prime the carberator? Is that as simple as turning the fuel selector to prime? I only ask cause I had this same problem last year and never did get it fixed.

Water Warrior 2 · 02-27-2014, 03:50 AM

Quote:

Originally Posted by Goose51683

Water warrior- prime the carberator? Is that as simple as turning the fuel selector to prime? I only ask cause I had this same problem last year and never did get it fixed.

Yup, just turn the lever to Prime for 10 or 15 seconds then back to Run.

**jonathan180iq** · 02-27-2014, 09:31 AM

Yeah. Just filling the float bowl a bit so there's something for the carb to use.

02-26-2014, 10:32 AM	#1
Bigrider Junior Member Join Date: Feb 2014 Posts: 4	Cam Orientation I recently replaced the head gasket. I took note of the orientation of the cam lines on the right side of the engine, white mark facing front, but failed to note if the engine was in compression or exhaust mode. I then inadvertently moved the crank to attach the cam chain. Now when I try to start, it cranks but won't start. Don't know if I have the cam 180% off or just a carb problem. Question. With the engine at TDC on compress stroke, which way should the white mark on the cam be facing (front or rear)? Also, I tried hand turning the crank to see when the spark plug fired but it only fires when I use the electric start. Is there a method using a pencil light probe to check when the circuit is firing. This would also help me understand which way to orient the cam. Thanks for any help Dave H San Antonio, TX Login or Register to Remove Ads
	1

02-26-2014, 11:19 AM	#3
Bigrider Junior Member Join Date: Feb 2014 Posts: 4	If I read, and remember correctly, the manual states putting the engine at TDC with the white mark facing the intake side. It didn't state whether the engine was on compression or exhaust. I would assume it would be on compression, but as stated the engine won't start so I just want to verify it needed to be "on compression". Dave H Login or Register to Remove Ads
	0

02-26-2014, 11:53 AM	#5
raul10141964 Senior Member Join Date: Apr 2012 Location: Elkhart, Indiana Posts: 369	TDC (top dead center) refers to the position of the piston, the engine reach TDC on compression stroke an on exhaust stroke. if you set the timing marks correctly the came time will bi OK Login or Register to Remove Ads
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02-26-2014, 10:58 AM	#2
raul10141964 Senior Member Join Date: Apr 2012 Location: Elkhart, Indiana Posts: 369	If you set the crank an the cam marks by the service manual will be correct
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02-26-2014, 11:33 AM	#4
Water Warrior 2 Senior Member Join Date: Dec 2006 Location: Squamish B.C Canada Posts: 11,409	If memory serves me correctly TDC refers to the compression stroke. Did you prime the carb before trying to start the bike? Just a thought.
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02-26-2014, 04:40 PM	#7
raul10141964 Senior Member Join Date: Apr 2012 Location: Elkhart, Indiana Posts: 369	if the crank is on TDC and the cam is on it's timing mark, is the compression stroke
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02-26-2014, 07:23 PM	#8
Goose51683 Senior Member Join Date: Apr 2013 Location: Indiana Posts: 621	Water warrior- prime the carberator? Is that as simple as turning the fuel selector to prime? I only ask cause I had this same problem last year and never did get it fixed.
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02-27-2014, 09:31 AM	#10
jonathan180iq Super Moderator Join Date: Jan 2007 Location: Dalton, GA Posts: 3,996	Yeah. Just filling the float bowl a bit so there's something for the carb to use.
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