Honda TRX 450R banner

1 - 3 of 3 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
Hey fellas starting lose compression burning about a half quart of oil after about 2 hours of riding so I’m assuming it’s time to rebuild the top end. Does anyone have a step by step thread or video or anything on how to tackle this project? Thanks
 

·
Registered
Joined
·
26 Posts
With the motor in the frame remove exhaust, drain oil and coolant.
Remove valve cover
Rotate engine to TDC
Remove 8mm bolt on cam chain tensioner
Insert small flat head and rotate CW until cam chain is completely loose
Remove Allen head bolts (6mm) holding cam gear
Remove gear then use something to hold chain so it doesn’t fall into the engine
Remove (4)10mm bolts holding cam tower
Remove cam tower
Remove (2) 8mm bolts on the side of cylinder head (shifter side)
Remove (4) head nuts and washers (Use a magnet to remove washers so you don’t drop them into the engine
Remove cylinder head (tap with a deadblow)
Remove (1) 8mm bolt holding cylinder on shifter side
Remove cylinder
Use a pick to remove piston circlip
Stick a socket on opposite side of where you removed circlip and drive out the wrist pin
Remove piston from connecting rod

Place new ring inside cylinder and use your piston to push it towards the top of the cylinder then take feeler gauges and check your ring gap by placing gauge into the ring gap
File to manufacturers specs


Put rings on piston oriented to manufactures specs then put the piston on the connecting rod.

Basically now you just start putting everything back together in the reverse order of tearing it apart.

Torque Specs:
Cylinder head 40 ft lbs ( I split it up into two passes) First pass at 20 ft lbs

Cam gear 14 ft lbs

Cam tower 10 ft lbs

The 8mm bolts on the side of head and cylinder I torque at 7 ft lbs along with the valve cover bolts.

To time the engine remove the timing cap on your clutch cover (10)mm Allen
Then remove the timing cap on your stator cover (6)mm Allen

Once the 10mm plug is removed on clutch side you will see a bolt inside.. place an 8mm Allen wrench on it and rotate motor until the arrow on the case lines up with the dot on the gear then look through your stator timing plug to see if that arrow lines up with the T on the flywheel

When everything is lined up install cam gear onto cam with the lines on the cam gear lined up (parallel) with the top of the cylinder head

Then check valve lash etc..

I may be forgetting a few things but that should put ya in the right direction. I gotta do a top end on my bike before long so I may do a write up on it later with pictures.
 
1 - 3 of 3 Posts
Top