Valve Adjustment Notes

[NoVa Rider]

Completed my first RX3 valve adjustment. Here are a few observations.

On removing tank: after removing side plastic, and removing rear bolt, lift tank up at rear and pull backwards to release it from the front rubber mount. At this point there are a number of hoses that need to be disconnected if you want to remove tank entirely. For me it was easier to disconnect the two electrical connections, and set the tank down sideways on an old bath towel where the drivers seat goes. (Be careful to completely cover the starter relay and battery terminals: shorting the battery with your fuel tank would probably void CSC's warranty.) I used a second rolled bath towel to help prop the tank up so it was not sitting on the fuel connection, and I also put a strap around the rear of the tank down to the foot peg to ensure it wouldn't topple off. Had to be careful, but this avoided pulling lines off of the tank fittings and disconnecting the fuel injection line.

Taking off the cover and adjusting the intake valves was easy. I set mine at .004 inches. (Edit -- oops, should have been .04 mm to 6mm). But the exhaust valves were a different matter. CSC advises taking the radiators off of their mounts to give you more room for access, but I had difficulty finding a wrench that would fit the upper mount bolts: they are easy to see but the upper radiator hoses make it difficult to put a socket on them, and their position under the frame makes it difficult to get a wrench on them. (Edit: 8mm T handle like Spud suggests or an 8mm 1/4 inch socket on an extension works. ) So I tried leaving the radiators in place, got the cover off the exhaust valves, and squirmed around until I found a position where I could see the valve adjusters and get a hand on them. I eventually got a .006 feeler gauge under both, liked the setting, so I did not have to adjust either exhaust valve. (Again, oops -- should have used a .06 mm gauge!) It's better to unbolt the radiators.

As I prepared to reinstall the tank, I found a curved tab on the inner right frame member just where the fuel line "cannister" (the fuel filter) goes. Looked to me as if the tab was intended to secure a fuel line for a carb version of the RX3: it did not fit around the fuel filter and also would not fit into a slot on the side of the filter. I ended up bending the tab downwards slightly (its light metal and will break off easily), and just ensured that nothing was pinched as I reinstalled the tank. I considered using a zip tie to help secure the fuel line but decided against it.

Not a lot of problems. A couple of places reminded me that the RX3 is not quite up to Japanese fit/finish/assembly standards. Such as the curved tab that does not seem to fit the fuel injection line, and also a couple of cross threaded bolts holding the plastic in place. But its all back together and working well.

[SpudRider]

Originally Posted by NoVa Rider

Completed my first RX3 valve adjustment. Here are a few observations.

On removing tank: after removing side plastic, and removing rear bolt, lift tank up at rear and pull backwards to release it from the front rubber mount. At this point there are a number of hoses that need to be disconnected if you want to remove tank entirely. For me it was easier to disconnect the two electrical connections, and set the tank down sideways on an old bath towel where the drivers seat goes. (Be careful to completely cover the battery terminals: shorting the battery with your fuel tank would probably void CSC's warranty.) I used a second rolled bath towel to help prop the tank up so it was not sitting on the fuel connection, and I also put a strap around the rear of the tank down to the foot peg to ensure it wouldn't topple off. Had to be careful, but this avoided pulling lines off of the tank fittings and disconnecting the fuel injection line...

After removing the rear bolt from the fuel tank, I pulled the tank back from the rubber mount. Then I placed the tank on top of the rubber mount so I had enough clearance beneath the tank to unhook the two vent hoses, and the two electrical connections for the fuel pump and the fuel gauge. With all other hoses and wires disconnected, I then disconnected the fuel line from the fuel filter. As the fuel started to leak, I flipped the fuel tank upside down, and the leaking stopped. Then I moved the fuel tank away from the bike, and set it to rest in the upside down position.

Originally Posted by NoVa Rider

...CSC advises taking the radiators off of their mounts to give you more room for access, but I had difficulty finding a wrench that would fit the upper mount bolts: they are easy to see but the upper radiator hoses make it impossible to put a socket on them, and their position under the frame makes it difficult to get a wrench on them. A wrench with a swivel socket end might work but I don't have one. So I ended up leaving the radiators in place, got the cover off the exhaust valves, and squirmed around until I found a position where I could see the valve adjusters and get a hand on them. I eventually got a .006 feeler gauge under both, liked the setting, so I did not have to adjust either exhaust valve. It would have been doable but fiddly. Perhaps I'll time my next valve adjustment to coincide with a coolant change so I can remove top radiator hoses, and get the radiators moved out of the way, just in case the exhaust valves need adjusting...

I used my Tusk Compact T-Handle Wrench Set to remove the radiator bolts. I believe I used the 8mm socket. I am sure one will find it very frustrating, if not impossible, to adjust the exhaust valve lash without getting the radiators out of the way. The T-handle sockets make this job, and many other jobs very easy. I highly recommend this T-handle wrench set.

https://www.rockymountainatvmc.com/p...t-handle%20set



I use these T-handle wrenchs all the time while working on my Honda CRF250X. I don't know what I would do without these tools.

[NoVa Rider]

Good suggestions Spud. I hadn't thought about flipping the tank to keep fuel from running out after disconnecting the fuel line.

[SpudRider]

Thank you for starting this thread, and sharing your experience. If everyone shares his tips, we can all learn from each other.

[Co2]

This theme is pure mystery, NovaRider said 004 "inch", but i research and coming ansvers is sad 004"milimeter" and 006 "milimeter" ...

Solved methodology : need a victim^^ a zero kilometer rx3 owner, and first job making for help checking the valve values.

Or need zs177mm " services manual " , thanks for topic.

[SpudRider]

The CSC RX3 Service Manual species the following valve clearances.

Intake valves: 0.04-0.06 mm
Exhaust valves: 0.04-0.06 mm

[Co2]

Originally Posted by SpudRider

The CSC RX3 Service Manual species the following valve clearances.

Intake valves: 0.04-0.06 mm
Exhaust valves: 0.04-0.06 mm

Thank you

[NoVa Rider]

My mistake on the valve adjustment clearances. Thanks to Co2 and Spud for catching this!

There was already a discussion of this on the valve clearance sticky.

What threw me off was my prior experience working on cars and motorcycles. My experience is that .004 inch to .008 inch (often called '4 thou' or '8 thou') is a common range for valve clearances. So when I saw the .04 to .06 range for the RX3, I failed to look closely and just assumed we were talking 4 to 6 'thou', rather than .04 to .06 mm.

Also, when I just did my first adjustment, I found the exhaust valves were both almost exactly .006 inch, so that reinforced my belief that we were in fact dealing with 'thou' rather than mm.

In fact, the sticker on the RX3 indicates the range should be .04 mm to .06 mm. Just like the CSC materials.

.05 mm is roughly equivalent to .002 inch. I have that blade on my feeler gauge, so I plan to redo the valve adjustment and set them at a middle spec of .002 inch. Once I get a wrench to fit the upper radiator bolts, that is.

.002 inch is a tight clearance in my experience, but then this is a small displacement motor with four valves.

I've only ridden a few miles with the looser valve settings, which were close to the original settings anyway, so I can't comment on whether I was hearing more valve "tappy."

[Co2]

Mystery is'not end service manual and adviced sad 0.04 milimeter(20/1milimeter?) intake , 0.06 milimeter exhaust
0.02 inch = 0.508 millimeters ? ( i understand this is a half milimeter?? )

My old and new filler gauge ( old start 0.05 and plus all 0.5 milimeter +++, but new start 0.02 and all 0.02++ 0.04+0.06+0.08....)

Values = 0.04 - 0.06 milimeter? i understand 1/20 or 1/18 mikrometer?? or im wrong ?

Again, best methode a new rx3 user helped this theme, and all know this, coorporations always hide this service secrets because need services maintenance payment, but me and other little village peoples non always finding services problem this

[NoVa Rider]

There is an extra zero in the 'inch' figure. So it's .002 inch equals .051 mm. I think that should resolve the issue.

But thanks again for catching my mistake. I just reset my valves (and I did manage to get the upper radiator bolts out). I set the intakes to .002 inch, but went with a .003 inch gauge for the exhausts. Looser than the Zongshen spec (its closer to .08 mm rather than .06 mm) but close enough I think, especially since the bike only has 500 miles on it.

Maybe it's my imagination but it does seem quieter.

Thanks again for helping me through this. I feel like a noob again.

[dave92029]

I turned 600 miles today and I'm planning on doing the 1000km service tomorrow.

I read this discussion and decided to verify that my Sear's feeler gauge had .06mm. It did not, so I went to the local Harbor Freight (open till 9pm on Sat.) with the 25% off July 4th coupon and picked a feeler gauge with .04mm &.06mm. I also got a free LCD flashlight.

Again Thank you. Wish me luck tomorrow taking the bike apart to get to the valves...and putting back together.

[SpudRider]

Good luck, Dave.

The first inspection/adjustment requires the most time. After you learn the tricks, the next inspection/adjustment will go much quicker.

[Co2]

0.04 Milimeter , 0.06 Milimeter values is CONFİRMED.

This my 3rd check valves story, but this time ok.

İmportant Note's : 4t motos 2x time find TDC(top dead center) , never try our hand skill (master skills) , every time moto block on screws remove and see all marks ok for tdc

Moto block down is camshaft/alternator/volant mark.

Moto block top 2 screw window is camsahft chain on marks as "IL" and "RL" marks .
follow and found, later adjusted valve's , other ways = damaged valve's , i experienced that theme
Good condition after 300 kilometer riding 0.04 and 0.06 mm sett new valves.



Have nice day's . co2.

[ElectricCircus]

Originally Posted by Co2

Mystery is'not end service manual and adviced sad 0.04 milimeter(20/1milimeter?) intake , 0.06 milimeter exhaust.

The service manual for the RX3's colombian version (AKT TT 250 Adventour, carbureted) states the same: 0,04mm intake, 0,06mm exhaust.

[SpudRider]

Several service manuals available to us in the United States, including the CSC Service Manual, give the following specifications for valve lash.

Intake valve: 0.04 - 0.06 mm
Exhaust valve: 0.04 - 0.06 mm

I have been using these specifications for over 10,000 miles, and I am sure they are correct.