HELP!! Auto Decompression - Honda TRX Forums: Honda TRX 450R Forum
 
LinkBack Thread Tools
post #1 of 11 (permalink) Old 10-24-2011, 01:13 PM Thread Starter
450r XC Rider
 
pwalston25's Avatar
 
Join Date: Feb 2011
Location: Central KY
Posts: 1,614
HELP!! Auto Decompression

Im working on an 08er and I adjusted the valves and they are perfectly in spec. but the thing will just not start. It has a hrc cam and i set the intakes to .006 and exhaust to .011. The intakes were very tight and the exhaust were dead on. I know it is something to do with the decomp. but I cant figure out what it is. I put a couple of pics up to show what it looks like all put together. Hopefully somebody will be able to pinpoint it if there is a problem with it. I put a new spark plug in it and have taken the cam tower off and cleaned the inside of the cam out twice. If appears to be moving properly when you pull the spring with your hand and the pin inside the cam moves, but it may not be closing or opening all the way. Im stumped right now and hopefully somebody can help me out. Oh and it will roll start and run like a champ. Its in time perfectly too.
Attached Images
File Type: jpg 2011-10-24 12.06.17.jpg (207.3 KB, 66 views)
File Type: jpg 2011-10-24 12.07.15.jpg (188.2 KB, 62 views)

"Ride or don't...Never quit"


08r with 06er engine
Racer's Edge AZ Head and Carb
CP Piston and Stage 3 HC
Full Hinson Clutch
Fox Float X Kashima
Houser +1 XC LT Arms
Fox Podium 2 with Derisi LT link
Precision Pro Stabilizer
Douglas G2 Beadlocks/Kenda Klaws
Houser nerfs, stem, and grab bar
Way Too Much More To List and More To Come
pwalston25 is offline  
Sponsored Links
Advertisement
 
post #2 of 11 (permalink) Old 10-24-2011, 02:55 PM
400EX Rider
 
skipnation's Avatar
 
Join Date: Jan 2009
Location: New York
Posts: 1,262
There was an 08ER recall concerning this. Have you looked into that? Maybe ask a dealer about the recall?

Four wheeels are better than two
skipnation is offline  
post #3 of 11 (permalink) Old 10-24-2011, 03:54 PM
250EX Rider
 
SRTmaniac's Avatar
 
Join Date: Feb 2011
Location: SoCal
Posts: 437
I think you may have the decomp cam and pin turned the wrong way. If you look at the pin it has a groove cut on one side that the decomp cam engages to move the pin up and down. It's hard to tell from your pics but it looks like the decomp weight is extended in the pic, when the bike is off the weight should be retracted toward the center line of the cam and the pin should be extented. If I am seeing correctly you might need to rotate the decomp pin and decomp cam 180deg.
I'm trying to think if you can even install the gear with the pin in backwards but I can't remember, either way this will either fix it or get you started on fixing it.

Or as Skip said pull the Decomp cam out and make sure the little pin that engages the decomp pin hasn't broken off.

Hope it helps.



04-09 450r Factory Service Manuals


08' ER
Barker's Exhaust
HotCams Stg II
Green wire mod
HRC jet kit
Uni Filter (Green NoToil oil)
CST Ambush rears
Dual 35w 6000k HIDS
Pro Armor Revolution nerfs

Last edited by SRTmaniac; 10-24-2011 at 03:57 PM.
SRTmaniac is offline  
post #4 of 11 (permalink) Old 10-24-2011, 04:09 PM Thread Starter
450r XC Rider
 
pwalston25's Avatar
 
Join Date: Feb 2011
Location: Central KY
Posts: 1,614
thanks for the answers guys. its got the hrc cam so i think the recall would only be on the stock cam. not 100% sure though. and we took the cam out and inspected the pin and found nothing. i bet we have literally took it apart 20 times and it just wont work right. when you pull on the spring-loaded gear that pulls the cam pin, the pin in the cam moves back and forth. i just dont know if its moving far enough to open the valves to the right spec. we have flipped the cam and shaft inside the cam around several times and still nothing.

"Ride or don't...Never quit"


08r with 06er engine
Racer's Edge AZ Head and Carb
CP Piston and Stage 3 HC
Full Hinson Clutch
Fox Float X Kashima
Houser +1 XC LT Arms
Fox Podium 2 with Derisi LT link
Precision Pro Stabilizer
Douglas G2 Beadlocks/Kenda Klaws
Houser nerfs, stem, and grab bar
Way Too Much More To List and More To Come
pwalston25 is offline  
post #5 of 11 (permalink) Old 10-24-2011, 04:23 PM
250EX Rider
 
SRTmaniac's Avatar
 
Join Date: Feb 2011
Location: SoCal
Posts: 437
Is the top of the pin worn down, maybe? I have no earthly idea what the spec is on the pin maybe someone has one laying around that they can measure or the service manual might say. Or look at the pin and see if it shows any signs of wear. Check the compression with a gauge to see just what it is.

I'm just throwing stuff out now.



04-09 450r Factory Service Manuals


08' ER
Barker's Exhaust
HotCams Stg II
Green wire mod
HRC jet kit
Uni Filter (Green NoToil oil)
CST Ambush rears
Dual 35w 6000k HIDS
Pro Armor Revolution nerfs
SRTmaniac is offline  
post #6 of 11 (permalink) Old 10-24-2011, 05:55 PM
450R Racer
 
450tr's Avatar
 
Join Date: Dec 2010
Location: waukomis, ok
Posts: 2,860
well it crank over? or just not start while cranking?

Keep it simple
450tr is offline  
post #7 of 11 (permalink) Old 10-25-2011, 11:20 AM Thread Starter
450r XC Rider
 
pwalston25's Avatar
 
Join Date: Feb 2011
Location: Central KY
Posts: 1,614
ive tried all of that srt...except the compression gauge. and i dont have a manual and cant download one because my computer crashed and my work computer sucks ass. im gettin ready to just take it to the shop. i dont know about this auto decomp stuff. i tried to talk him into getting an 07 cam setup lol. 450tr yes it cranks over and over and it almost wants to start but its just not there. i just think the pin is not goin back closed all the way or is not opening all the way and isnt moving the valves far enough but ive tried everything i know to do

"Ride or don't...Never quit"


08r with 06er engine
Racer's Edge AZ Head and Carb
CP Piston and Stage 3 HC
Full Hinson Clutch
Fox Float X Kashima
Houser +1 XC LT Arms
Fox Podium 2 with Derisi LT link
Precision Pro Stabilizer
Douglas G2 Beadlocks/Kenda Klaws
Houser nerfs, stem, and grab bar
Way Too Much More To List and More To Come
pwalston25 is offline  
post #8 of 11 (permalink) Old 06-09-2015, 10:30 PM
TRX90 Rider
 
lsbufis's Avatar
 
Join Date: Dec 2014
Posts: 74
update on this?
lsbufis is offline  
post #9 of 11 (permalink) Old 06-09-2015, 10:38 PM
300EX Rider
 
Join Date: Jan 2013
Location: St. Augustine, FL
Posts: 513
whats your issue @isbufis
EZ4U2NV is offline  
post #10 of 11 (permalink) Old 06-11-2015, 11:15 AM
TRX90 Rider
 
lsbufis's Avatar
 
Join Date: Dec 2014
Posts: 74
my 2008 450er would not crank a full turn.. kinda like a dead battery... I put a new batt and changed my starter since I fried the other one and still barely cranks..

Called Honda Canada and they will repair free of charge.. waiting on them to get the parts..

Type your VIN here

http://motorcycle.honda.ca/safety/re...te32258k200233


What is the problem? During high-load operation at extremely low rpm, the crankshaft may experience instantaneous reverse rotation which momentarily actuates the engine decompressor system. When this happens there is excessive force on the decompressor actuation pin, causing it to bend or break. If the decompressor actuation pin is damaged the engine will not start.
lsbufis is offline  
post #11 of 11 (permalink) Old 07-11-2019, 07:32 AM
TRX90 Rider
 
Join Date: Jul 2019
Posts: 1
Im having the same problem..i got the new pin and small shaft that goes as a kit.. This is the second day im strugling to put it together... Is there someone with a video that can help me please.. Thanks
HondaLov3r450eR is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Honda TRX Forums: Honda TRX 450R Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome