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Here is the way to find TDC on TRX300fx

Use a flashlight to look inside the left hole to see a "T on its side" lined up with the index arrow inside the case while you rotate the starter reduction shaft counter clockwise (hole on the right with the driver handle in it) Access is accomplished by removing the plug covers with a large screwdriver. The starter reduction shaft needs a 25 Torx bit.

Ensure engine is on compression stroke and not exhaust stroke.
 

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Discussion Starter #23
View attachment 55306

Here is the way to find TDC on TRX300fx

Use a flashlight to look inside the left hole to see a "T on its side" lined up with the index arrow inside the case while you rotate the starter reduction shaft counter clockwise (hole on the left with the driver handle in it) Access is accomplished by removing the plug covers with a large screwdriver. The starter reduction shaft needs a 25 Torx bit.
ummm..yeah you will get TDC alright, but..will it be on compression stroke ?, or exhaust stroke ?. must be on compression stroke..big difference !.
 

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Another simple way is to remove the spark plug put your finger over the plug hole and bump the starter or turn the flywheel by socket until you feel air pushing on your finger, then using a long dowel rod or screw driver stick it in the plug hole and slowly turn the crank until the piston is at the top of the cylinder and the "-"by the T is aligned with the notch in the cover.
 

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Discussion Starter #25
Another simple way is to remove the spark plug put your finger over the plug hole and bump the starter or turn the flywheel by socket until you feel air pushing on your finger, then using a long dowel rod or screw driver stick it in the plug hole and slowly turn the crank until the piston is at the top of the cylinder and the "-"by the T is aligned with the notch in the cover.
yep..agreed ^^^.
 

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View attachment 55306

Here is the way to find TDC on TRX300fx

Use a flashlight to look inside the left hole to see a "T on its side" lined up with the index arrow inside the case while you rotate the starter reduction shaft counter clockwise (hole on the left with the driver handle in it) Access is accomplished by removing the plug covers with a large screwdriver. The starter reduction shaft needs a 25 Torx bit.
ummm..yeah you will get TDC alright, but..will it be on compression stroke ?, or exhaust stroke ?. must be on compression stroke..big difference !.

I posted this in an effort to show people with a similar engine design a different method for manipulating their engine into the proper position, and I did not see this method mentioned anywhere in this forum and I thought it would be educational. It is the method used in the Service manual. I forgot to add to be sure to be on compression stroke and will edit. .

Your original post talks in excellent detail about the process, but on my 94 TRX300fx, the only way I was able to advance the engine was by hitting the starter or by the kick starter. I did the latter by removing the kick starter and laying a piece of baling wire in the splines of the extended shaft and then used a 18mm 12 point socket wrench on the splined shaft. (17mm too small, 18mm too big) I was able to find top dead center using this method coupled with the dowel rod in the spark plug hole technique.

Afterwards, I discovered a Service Manual on YouTube and it showed the technique I described, which I found way easier and to be more accurate.

I don't know how to "Turn the crank backwards" on this Quad, as you mentioned in the original post. I don't think turning the starter reduction shaft clockwise will do anything.
 

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Helpful is good. I have mechanic fear especially on Honda valves. Our dealer here gets pretty good dough for valve adjustment and the service interval is pretty tight. As I have a Silverwing too, I would save a bundle if I had valve confidence. Thanks for the post, shadetree.
 

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Discussion Starter #28
Helpful is good. I have mechanic fear especially on Honda valves. Our dealer here gets pretty good dough for valve adjustment and the service interval is pretty tight. As I have a Silverwing too, I would save a bundle if I had valve confidence. Thanks for the post, shadetree.
your welcome, I hope I made it easier , and cheaper for ya ?..lol.
 

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Discussion Starter #29
View attachment 55306

Here is the way to find TDC on TRX300fx

Use a flashlight to look inside the left hole to see a "T on its side" lined up with the index arrow inside the case while you rotate the starter reduction shaft counter clockwise (hole on the left with the driver handle in it) Access is accomplished by removing the plug covers with a large screwdriver. The starter reduction shaft needs a 25 Torx bit.
ummm..yeah you will get TDC alright, but..will it be on compression stroke ?, or exhaust stroke ?. must be on compression stroke..big difference !.

I posted this in an effort to show people with a similar engine design a different method for manipulating their engine into the proper position, and I did not see this method mentioned anywhere in this forum and I thought it would be educational. It is the method used in the Service manual. I forgot to add to be sure to be on compression stroke and will edit. .

Your original post talks in excellent detail about the process, but on my 94 TRX300fx, the only way I was able to advance the engine was by hitting the starter or by the kick starter. I did the latter by removing the kick starter and laying a piece of baling wire in the splines of the extended shaft and then used a 18mm 12 point socket wrench on the splined shaft. (17mm too small, 18mm too big) I was able to find top dead center using this method coupled with the dowel rod in the spark plug hole technique.

Afterwards, I discovered a Service Manual on YouTube and it showed the technique I described, which I found way easier and to be more accurate.

I don't know how to "Turn the crank backwards" on this Quad, as you mentioned in the original post. I don't think turning the starter reduction shaft clockwise will do anything.
I have not been in this thread until today ?, but..if you removed the center cap on the left hand side case, you could use the 17mm crank bolt to turn the motor backwards.
 
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Helpful info here..
Will be trying this tomorrow thanks to the manual,google and shadetree cross my fingers...My last valve job was around 3 years ago done by Honda .
it's a 2013 C.T.E. FPA so i figure it's due.....

Q : Not doing this regular maintenance would it be that I'm burning oil....1263Km, 785 Miles had to add almost a quart of oil....
Oh ya ODO just turned 10,684Km 6639 Miles

Maybe time for a 680cc...haha
 

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Discussion Starter #31
Helpful info here..
Will be trying this tomorrow thanks to the manual,google and shadetree cross my fingers...My last valve job was around 3 years ago done by Honda .
it's a 2013 C.T.E. FPA so i figure it's due.....

Q : Not doing this regular maintenance would it be that I'm burning oil....1263Km, 785 Miles had to add almost a quart of oil....
Oh ya ODO just turned 10,684Km 6639 Miles

Maybe time for a 680cc...haha
maintenance is good, but not why your losing oil, your losing oil from worn oil rings on piston ?, or a leak somewhere from the engine.
 
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The FSM for my 2018 TRX500FM1 says do not rotate the crankshaft counter clockwise, it will activate the one way decompressor system and give an incorrect measurement, and that slack in the rocker arms is the indication that I am TDC on the right stroke. Is there any other way to confirm TDC?
 

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2013 420FPA.
Still haven't done this and the bike sounder louder yet but since it's nice day tomorrow will try to attempt....
So i been googleling how to do this,the manual is ready on the laptop and i think i have most of the tools to do this..
But when i get to the compression stroke to i adjust both valve on the compression stroke or do i do one or the other on the exhaust stroke....
 

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Always adjust all of the valves on single-cylinder motors with the motor at TDC on the compression stroke. Verify your work after the adjustments by rotating the motor in the normal direction of rotation for two complete revolutions watching the valves open and close and stop at TDC again (on compression stroke) to double-check your adjustments. Do not ever rotate the motor backwards... if you go past your mark continue on two more revolutions and try again to stop on the TDC mark.
 

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Always adjust all of the valves on single-cylinder motors with the motor at TDC on the compression stroke. Verify your work after the adjustments by rotating the motor in the normal direction of rotation for two complete revolutions watching the valves open and close and stop at TDC again (on compression stroke) to double-check your adjustments. Do not ever rotate the motor backwards... if you go past your mark continue on two more revolutions and try again to stop on the TDC mark.
So the compression stroke is the piston on top or is it sitting at bottom,that's were i get mixed up...and then leave it when it get to compression stoke with T Mark and i adjust both according to the manual gap specs..
 

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at the top or a hair past,, a very small hair. timing mark should help, unless you got a stretched chain.. TDC means top dead center. thats where you want to be. 4 cycle engine are a bit different than two cycles, they both are adjusted at TDC, with a 4 you have to make sure that your in the firing cycle, instead of exhaust cycle.
 

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at the top or a hair past,, a very small hair. timing mark should help, unless you got a stretched chain.. TDC means top dead center. thats where you want to be. 4 cycle engine are a bit different than two cycles, they both are adjusted at TDC, with a 4 you have to make sure that your in the firing cycle, instead of exhaust cycle.
ummm, two cycle engines, or i think you mean 2 strokes ?, they don't have valves to adjust :). only 4 stroke engines have valves, least as far as i know anyway ? :).
 
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at the top or a hair past,, a very small hair. timing mark should help, unless you got a stretched chain.. TDC means top dead center. thats where you want to be. 4 cycle engine are a bit different than two cycles, they both are adjusted at TDC, with a 4 you have to make sure that your in the firing cycle, instead of exhaust cycle.
ummm, two cycle engines, or i think you mean 2 strokes ?, they don't have valves to adjust :). only 4 stroke engines have valves, least as far as i know anyway ? :).
Leds' right, the old Detroit Diesel 71 series motors were two-cycle diesels having a gear driven Roots type (positive displacement) blower mounted on the side of the engine blocks that pumped air into the cylinder(s) through intake ports, but the exhaust was handled by either two or four valves per cylinder. The motors fired every time the piston(s) come up, thus they were a true two-stroke motor design having multiple valves per cylinder. Those exhaust valves were controlled by solid lifters too, so valve adjustments had to be performed on those motors at regular intervals... with each piston at TDC.

https://en.wikipedia.org/wiki/Detroit_Diesel_Series_71

When I was a teenager I worked on a 6-71 in a big old flat-nosed GMC semi truck. It had an air powered starter motor on it... I'll never forget the screaming noises that beast made cranking over to start it and then revving under load. Cool tech back then... those roots blowers were adapted for racing in the '50s, every Top Fuelie dragster on earth back then had a 6-71 GMC blower on them, and they still use the same blower design today. :)
 

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Now those were old school, hey retro, i got one for you.....lol did you know those old Detroits had a habit of turning backwards... Lol my uncle owns/runs a well drilling outfit, his main drill platform rig has a 12-V (silver = forced induction + turbos) that beast has 2 blowers , and 2 turbos, one things for sure they indeed have a very distinctive sound. A old school mechanic once told me if you owned a Detroit and parked it over night, if there was a few oli spots on the ground the next day ? Something was wrong .....haha! Most if not all. Have been around always a had a rpm lope , and had that emergency air damper shut off, i did see one run away one time, i have no idea how high the rpm got before the guy closed that air flap shut off......
 
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Discussion Starter #40
at the top or a hair past,, a very small hair. timing mark should help, unless you got a stretched chain.. TDC means top dead center. thats where you want to be. 4 cycle engine are a bit different than two cycles, they both are adjusted at TDC, with a 4 you have to make sure that your in the firing cycle, instead of exhaust cycle.
ummm, two cycle engines, or i think you mean 2 strokes ?, they don't have valves to adjust :). only 4 stroke engines have valves, least as far as i know anyway ? :).
Leds' right, the old Detroit Diesel 71 series motors were two-cycle diesels having a gear driven Roots type (positive displacement) blower mounted on the side of the engine blocks that pumped air into the cylinder(s) through intake ports, but the exhaust was handled by either two or four valves per cylinder. The motors fired every time the piston(s) come up, thus they were a true two-stroke motor design having multiple valves per cylinder. Those exhaust valves were controlled by solid lifters too, so valve adjustments had to be performed on those motors at regular intervals... with each piston at TDC.

https://en.wikipedia.org/wiki/Detroit_Diesel_Series_71

When I was a teenager I worked on a 6-71 in a big old flat-nosed GMC semi truck. It had an air powered starter motor on it... I'll never forget the screaming noises that beast made cranking over to start it and then revving under load. Cool tech back then... those roots blowers were adapted for racing in the '50s, every Top Fuelie dragster on earth back then had a 6-71 GMC blower on them, and they still use the same blower design today. :)
well, lets keep our mindset on atv engines here, and not diesel engines ?, because i know very little about those !..lol ( cept when they run out of fuel ?..they are a royal pain to get started again ). this is a atv forums, not your local truck garage , lol.
 
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