GT Valve Lash Adjustment
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Petty Tyrant
GTS250 GTS300 MP3 500
Joined: 11 Oct 2005
Posts: 29657
Location: Bay Area, California
Tue Jun 03, 2008 5:27 pm quote
Created article GT200: Valve Lash Adjustment

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Petty Tyrant
GTS250 GTS300 MP3 500
Joined: 11 Oct 2005
Posts: 29657
Location: Bay Area, California
Wed Jun 11, 2008 9:13 pm quote
Changed name of this article
Addicted
09 GTS300 Super black, 04 GT 200 smoky, 05 GT 125 smoky (in pieces)
Joined: 05 Jul 2006
Posts: 738
Location: Barcelona
Mon Jan 25, 2010 6:49 am quote
I just got through doing this yesterday and managed to get it right the second time around.

I think it would be beneficial to others taking this on for the first time to clarify that the clearance is best measured pushing down on each rocker arm first with the feeler gauge inserted, to make sure that you're measuring the actual clearance and there is no additional play.

I say this because the rocker arms tend to clamp down on the feeler gauge under their own weight and even though you're getting a 'slight drag' with the feeler gauge, there's actually a bigger gap if you pull the arm up.

After doing it the first time and buttoning everything up I found the valves were extremely noisy and had to take everything apart to reset the clearances again with the above caveat in mind. Hope this helps. I know it would've helped me.
Ossessionato
Joined: 04 Aug 2007
Posts: 2813
Location: Austin
Fri Jun 04, 2010 7:46 am quote
A couple things to add:

It's really not necessary to half drop the engine out to get to the valves, especially on the GT. I suppose if it's your first time, it may help to get a good look at everything. Honestly, though, there is plenty of room to remove the valve cover and get both hands on the valves.

Secondly, I'm not sure why the OP shows the checking of the crank timing mark. I think he has it backwards. Every other time the crank mark is aligned, the cam mark won't be (TDC overlap) but every time the 4V cam mark is aligned (TCD compression) the crank mark will always be aligned. It is the crank that turns twice for every one turn of the cam in a four-stroke engine.

Hope this helps!
Petty Tyrant
GTS250 GTS300 MP3 500
Joined: 11 Oct 2005
Posts: 29657
Location: Bay Area, California
Fri Jun 04, 2010 2:49 pm quote
drewteague wrote:
A couple things to add:

It's really not necessary to half drop the engine out to get to the valves, especially on the GT. I suppose if it's your first time, it may help to get a good look at everything. Honestly, though, there is plenty of room to remove the valve cover and get both hands on the valves.

Secondly, I'm not sure why the OP shows the checking of the crank timing mark. I think he has it backwards. Every other time the crank mark is aligned, the cam mark won't be (TDC overlap) but every time the 4V cam mark is aligned (TCD compression) the crank mark will always be aligned. It is the crank that turns twice for every one turn of the cam in a four-stroke engine.
Those are good points, but I would encourage you to go ahead and edit the article to improve it. It's a group effort, and you have the power.
Ossessionato
Joined: 04 Aug 2007
Posts: 2813
Location: Austin
Sat Jun 05, 2010 6:57 am quote
Article edited!

I removed the unnecessary step (and associated pictures) concerning checking the timing mark on the crank. Also, added notes about the multiple timing marks on the cam gear, noting to make certain you are on the correct mark for your engine. Finally, added a note describing how not to overtighten the adjustment.
Petty Tyrant
GTS250 GTS300 MP3 500
Joined: 11 Oct 2005
Posts: 29657
Location: Bay Area, California
Sat Jun 05, 2010 2:42 pm quote
Gracias!
Member
MP3 250
Joined: 17 Oct 2009
Posts: 33
Location: San Diego
Fri Apr 27, 2012 7:56 pm quote
GT Valve Lash Adjustment
Just finished doing them, again, primarily because I was worried about the decompression device. I did them the first time by pulling the spark plug (needed a new one anyway) and bumping the engine with the starter until it stopped with one set of valves depressed. Then I adjusted the other set. Then bumped it again until the newly adjusted valves were depressed. When I did this job the second time (by the book) there was very little change. Could someone tell me if the decompressor is a problem for this method? Thanks.
Cal

Of course I grounded the plug so as not to stress the ignition.
Hooked
2007 GT 200L
Joined: 20 Nov 2012
Posts: 207
Location: S C
Wed May 08, 2013 6:28 am quote
GT 200 access to valve cover
I noticed drewteagues' post

" It's really not necessary to half drop the engine out to get to the valves, especially on the GT. I suppose if it's your first time, it may help to get a good look at everything. Honestly, though, there is plenty of room to remove the valve cover and get both hands on the valves. "

I looked at my 2007 GT 200 and was wondering if there would or may be a video showing working in that confined space.
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