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View Full Version : TRX450R Valve Adjustment HOW-TO



ghott
02-22-2007, 05:01 PM
This is my own personal Valve Adjustment HOW-TO write up for the TRX450R....complete with detailed pictures.

Its long winded...but its complete and, I would venture to say, idiot proof.

It outlines the tools you need, steps, precautions, and detailed pictures.

Special thanks to all of those involved behind the scenes!

http://www.garyhott.com/valves.html

ohsobad_chevy
02-22-2007, 05:24 PM
Very nicely done!!!! :cool:

d3ktrix
02-22-2007, 06:18 PM
Very nice, didn't get to read the entire thing yet but the pictures alone are 10 times better then the ones in most of the other guilds.

I'll be using it soon when I switch from my HRC cam to my HC2.

wykyd450R
02-22-2007, 06:20 PM
Awesome job!! ;)

Houser450
02-23-2007, 01:32 PM
just a question, is it possible to be at the tdc and to be 180 degrees off

Sjorge450R
02-23-2007, 06:54 PM
Originally posted by Houser450
just a question, is it possible to be at the tdc and to be 180 degrees off

not are long are the lobes are facing the rear.

ghott
02-25-2007, 12:39 PM
Originally posted by Houser450
just a question, is it possible to be at the tdc and to be 180 degrees off

There are TWO TDC's on these bikes. Why? Because for each crank rotation, the cam only rotates 180 degrees. So two rotations of the crank = one rotation of the cam. This is known as a wasted spark engine...

You need to be at the TDC where the cam lobes are facing towards the rear of the bike, and slightly up.

Hope this helps.

Chino886
02-25-2007, 09:11 PM
Originally posted by Houser450
just a question, is it possible to be at the tdc and to be 180 degrees off

No, this is known as BDC or bottom dead center!

d3ktrix
02-25-2007, 09:27 PM
Originally posted by Chino886
No, this is known as BDC or bottom dead center!

4 strokes hit TDC twice for every ignition
2 strokes hit TDC once for every ignition

Like ghott said, the crank rotates twice for every one rotation of the cam in a 4 stroke.

Thats how I understand it anyway =)

Chino886
02-25-2007, 09:32 PM
Originally posted by d3ktrix
4 strokes hit TDC twice for every ignition
2 strokes hit TDC once for every ignition

Like ghott said, the crank rotates twice for every one rotation of the cam in a 4 stroke.

Thats how I understand it anyway =)

We are both thinking the same thing, but one important thing you want to remember is when shimming and changing cams you want to be at TDC on compression stroke, the other TDC is decomp stroke. ;)

ghott
02-25-2007, 10:47 PM
Like everyone has said...you want to be on the correct TDC, that is, with the lobes pointing towards the rear of the quad, and slightly up.

You CAN TRY to do it on the other TDC...with the cam rotated 180 degrees...but its not fun fighting those exhaust springs!

trx450jason
02-26-2007, 08:41 PM
the writeup has helped me a lot but could it be any harder to adjust the intake valves?

ghott
02-26-2007, 09:43 PM
Originally posted by trx450jason
the writeup has helped me a lot but could it be any harder to adjust the intake valves?

I'm not sure what you are asking..could you elaborate on your question a little furthur?

trx450jason
02-27-2007, 10:01 AM
The intake vavles are hard to get to with a feeler gauge. I wasn't using the pre-bent ones because I have heard you don't need them but I will pick some up tonight so that should make it easier. What kind of feel are you exactly looking for with the feeler guage to know the correct size? I know your suppose to be able to move it around still but I have no idea how easily it should move.

GIXXER1KR
02-27-2007, 04:56 PM
Hey got where do u recommend getting a digital caliper.I have a micrometer thats like a c clamp but a pita to read.I have seen them at sears but seem rather expensive but again it will be something ill be getting use outta!!!

trx450jason
02-27-2007, 05:58 PM
i have a digital caliber and it has save me A LOT of time so far.. i already had one though so didnt have to mess with how expensive they are haha.. but well worth it

d3ktrix
02-27-2007, 06:16 PM
My bike has about 5 months of riding on it, and it still starts first kick almost every time and runs perfect.
Should I still bother to check the valves yet? or wait till it's a little harder to start?

I would think it would be best to check before any signs show, but how soon is too soon?

trx450jason
02-27-2007, 08:48 PM
i would say go for it.. its really easy to check the valves the only hard part is if you have to actually adjust them. but just to check them all you have to do is remove about 10 bolts

ghott
02-28-2007, 06:12 AM
Originally posted by trx450jason
The intake vavles are hard to get to with a feeler gauge. I wasn't using the pre-bent ones because I have heard you don't need them but I will pick some up tonight so that should make it easier. What kind of feel are you exactly looking for with the feeler guage to know the correct size? I know your suppose to be able to move it around still but I have no idea how easily it should move.

You are looking for sort of a medium feel. Stick several size feeler gauges in. You will be able to tell which feeler gauge is the correct size by using the wrong feeler gauges. You are looking for a snug feel, but you should still be able to move the gauge around freely. And yes....DEFINITELY use the angled feeler gauges for the intake valves. If yo udon't want to buy angled gauges, you can bend the straight ones to fit. They will probably stay permanently bent.


Originally posted by GIXXER1KR
Hey got where do u recommend getting a digital caliper.I have a micrometer thats like a c clamp but a pita to read.I have seen them at sears but seem rather expensive but again it will be something ill be getting use outta!!!

Sears do have some very nice calipers....and yes they are expensive. If you can't afford one now, I would suggest borrowing one from a friend or co-worker.


Originally posted by d3ktrix
My bike has about 5 months of riding on it, and it still starts first kick almost every time and runs perfect.
Should I still bother to check the valves yet? or wait till it's a little harder to start?

I would think it would be best to check before any signs show, but how soon is too soon?

I would definitely check them. Like stated before, it doesn't take that much time to check the valves. And its always better to be safe than sorry. If everything is still in spec, at least you'll have the peace of mind.

trx450jason
02-28-2007, 07:31 AM
well i have it all figured out and back together and it runs and starts so much better than before.. i put in the Hot Cams 2 cam and the motor runs a little louder but ive heard thats normal. your writeup helped a lot

ghott
02-28-2007, 12:15 PM
Thanks for the kind words...

And yes....

In my bike, both the Hot Cams Stage 2, and Stage 3 have ticked much louder than a stock cam. As long as your clearances are on, your golden.

d3ktrix
03-31-2007, 01:33 AM
Found an error in the guild tonight while I was installing my 02 CRF cam.

Nothing major.

In step 7 it says:



"Set the engine to TOP DEAD CENTER (TDC) by completing the following tasks: Remove the Crankshaft Hole Cap (10mm allen wrench) on the bottom right side of the engine (near the transmission fluid check hole). Inside the crankshaft hole, use a 10mm allen wrench to rotate the crank manually to line up the timing marks on the sprocket and case (shown in the first picture below circled in GREEN)."


To turn the crank shaft, you need to use an 8MM allen wrench, not a 10MM.
10MM is correct for the cap still though.

Your guild was super helpful tho, thanks =)

ghott
04-01-2007, 05:59 PM
Originally posted by d3ktrix
Found an error in the guild tonight while I was installing my 02 CRF cam.

Nothing major.

In step 7 it says:



To turn the crank shaft, you need to use an 8MM allen wrench, not a 10MM.
10MM is correct for the cap still though.

Your guild was super helpful tho, thanks =)

Thank you, I will change that ASAP!

ghott
04-03-2007, 11:12 AM
Updated it today.

redrider03
08-14-2007, 08:38 AM
Very nicely done!!! Looks good

ghott
02-08-2008, 09:49 AM
Originally posted by redrider03
Very nicely done!!! Looks good

Thanks!

wildheer
02-12-2008, 01:13 PM
Hello, i want to say that this is an excellent how to and very well done. I have a question about shims. I have an 06 450R and i will be installing the HRC soon but my questions are just assuming keeping everything stock. When it comes to adjusting the valves, are there no screw adjustments? The full adjusting is done through shim replacement only? How do the shims get out of adjustment? Is that just through the natural wearing of them? Assuming keeping the same CAM, how would you ever need to add a smaller shim if this is the case. It would seem the adjustment would always be adding the exact shim the bike came with or maybe slightly bigger to make up for another part wearing but how could you ever put a smaller one in? Also, i didnt see where you mention adjusting the decompressor clearance after the valve adjustment. I do understand this is done by an adjustment screw and the manual says to always do this after a valve adjustment or inspection. What is your take on this? Thanks again for such an informative how to.

golfer2000
08-14-2008, 09:08 PM
Originally posted by trx450jason
i would say go for it.. its really easy to check the valves the only hard part is if you have to actually adjust them. but just to check them all you have to do is remove about 10 bolts
What do you do if you are just checking clearances? which 10 bolts?

ghott
08-26-2008, 09:55 AM
Originally posted by wildheer
Hello, i want to say that this is an excellent how to and very well done. I have a question about shims. I have an 06 450R and i will be installing the HRC soon but my questions are just assuming keeping everything stock. When it comes to adjusting the valves, are there no screw adjustments? The full adjusting is done through shim replacement only? How do the shims get out of adjustment? Is that just through the natural wearing of them? Assuming keeping the same CAM, how would you ever need to add a smaller shim if this is the case. It would seem the adjustment would always be adding the exact shim the bike came with or maybe slightly bigger to make up for another part wearing but how could you ever put a smaller one in? Also, i didnt see where you mention adjusting the decompressor clearance after the valve adjustment. I do understand this is done by an adjustment screw and the manual says to always do this after a valve adjustment or inspection. What is your take on this? Thanks again for such an informative how to.

The valve seats will wear over time/use and require the shim adjustments...they are a normal wear and tear item. You can certainly minimize the amount you will have to adjust the valves by using high quality valves, seats, guides, and springs as well as using a cam which is easy on the valve train and doing routine oil changes and air filter cleanings.

The decompressor adjustment is something I didn't want to include in the how-to because I don't feel its all that necessary. Others may disagree with me, but I've never had to adjust mine. In addition to that, there are varying ways to check the decompressor arm adjustment to...whether it be with a compression gauge or a simple feeler gauge test. I believe there is also a big difference as to what year bikes like what kind of decompressor adjustment...the kickers vary from the electric starts. I really didn't want to get into all that. Just follow what your manual or engine builder recommends.


Originally posted by golfer2000
What do you do if you are just checking clearances? which 10 bolts?

4 bolts - front plastic to gas tank/frame
2 bolts - gas tank to frame
4 bolts - valve cover

VOILA! :)

chevys&honda$
05-05-2009, 02:09 PM
bump

ghott
02-19-2014, 07:55 AM
Bumping this for others.

2001400exrida
02-19-2014, 08:09 AM
yup, great write up! Sometimes it's scary going in to do this for the first time, but if you follow this guide it's a no brainer. Once you do it one time you'll have the confidence to do it everytime. Decomp can be confusing, but the easiest method i find for it is to use the service manual to check it. use feelers and set the gap right where it should be.

Crosshairs
02-22-2014, 08:47 AM
There are TWO TDC's on these bikes. Why? Because for each crank rotation, the cam only rotates 180 degrees. So two rotations of the crank = one rotation of the cam. This is known as a wasted spark engine...

great write up, just wanted to point something out....2 TDC's are inherent to all 4 stroke engines, it has nothing to do with a waste spark ignition...