New Zongshen RX3 (ZS250GY-3) Dual Sport

[SpudRider]

As always, thank you for posting the superb information and excellent photographs, Kat.

Did you release much pressure when you unhooked the fuel filter from the fuel pump? I assume any leaking fuel is the result of the pressurized fuel line, and the leaking will stop after the pressure is vented. If so, you can tilt the fuel tank more horizontally, and no more fuel will leak from the hose.

According to the CSC tutorial, you can get more working space to adjust the valves by loosening the radiator mounts. You don't need to drain the coolant, or disconnect any of the hoses.

http://californiascooterco.com/blog/?p=14703

Are the radiators, the coolant hoses, or both, blocking access to the exhaust valve tappets? Do you plan to work from above, or from the front, left side of the bike to adjust the exhaust valves?

[SpudRider]

Katflap,

Are you filling the fuel tank with regular octane, or high octane fuel?

[SpudRider]

I wonder regarding the purpose of the spare electrical connector.

[detours]

Originally Posted by SpudRider

I wonder regarding the purpose of the spare electrical connector.

The same question came up yesterday on Facebook in the Cyclone RX-3 Zongshen Owners Group. The only response was maybe it's for an optional projector lamp.

[SpudRider]

Originally Posted by detours

The same question came up yesterday on Facebook in the Cyclone RX-3 Zongshen Owners Group. The only response was maybe it's for an optional projector lamp.

Thank you. Can you please provide a link for that Facebook page?

[NoVa Rider]

We all know that the RX-3 uses screw and lock-nut adjusters to set valve clearance. This is one of the features that makes the bike owner-serviceable, since you don't need a set of shims and you don't need to demount the cam shaft to adjust valve clearance.

Many of you are already well familiar with adjusting valves. But I thought I would share a few tricks I picked up adjusting valves on hundreds of air-cooled VWs, along with many motorcycles, over the years. If you know how to do it, no need to read further.

I have not yet received my RX-3, so these are general instructions. CSC's tutorial covers the specifics of removing body work, loosening the radiator mounts, removing the valve cover, and setting the engine to the correct position.

Once you have the valve cover off and are ready to measure, its always helpful to make sure the adjusters have some free play in them. You should be able to hold on to the adjuster or even just put you finger on it and wiggle it a bit. If you can't feel any freeplay, you may have the motor in the wrong position. If the motor is in the correct position, you should be able to wiggle all the adjusters.

Next is inserting the feeler gauge. Depends on how much room you have. You may have difficulty simply pushing the gauge between the adjuster and the valve stem; but often you can insert the blade of the gauge into the space beside the rocker, and then draw the blade back while gently pushing it into the gap. We'll see how much room we really have in the RX-3 to see if further tricks may be necessary.

But if you can't get the blade into the gap no matter what you do, the adjustment may be too tight. Try a thinner gauge just to be sure you are doing it correctly, and to measure what the adjuster is actually set at, just for grins.

So you have the correct gauge in place. If adjusted correctly, you should feel a drag while drawing it straight backwards from the gap. The gauge may tend to buckle if you try to push it further in, but if you can draw it back without having difficulty holding onto the gauge, you are OK. If you feel no drag, and you're sure the blade is in the gap, the setting is too loose and you need to adjust.

So if you have followed me this far, here are the real secrets. You would think that the adjustment is done by loosening the lock nut, perhaps loosening the adjustment screw a bit to get the guage in place, then turning the adjustment screw until you have the correct drag on the gauge, and retightening the lock nut. Well, not so fast.

Two things can happen when you try to tighten the lock nut. The first is that the nut can "drag" the adjuster with it as you tighten it, so you end up with a setting that's too tight. The second thing is a bit more subtle. When you tighten the lock nut, presuming the adjuster doesn't "drag" with the nut, the nut actually draws the adjuster up slightly against the threads as its tightened. This actually increases the gap a bit.

The solution? First, set the adjuster so its a bit tighter that you would like. So that you can just barely pull the gauge back. Then, put your wrench on the lock nut, and set your screwdriver in the adjuster slot. As you tighten the lock nut, apply slight "back pressure" on the adjuster. Not enough to turn the adjuster, just enough to keep it from being "dragged" by the lock nut. Then, since you started with setting a bit tighter that you wanted, as you tighten the nut, you should find the adjustment loosens just a bit.

At this point, DO NOT TO OVERTIGHTEN THE LOCK NUT. Particularly on a small nut/adjuster arrangement like the RX-3, it does not take a lot of torque to secure the lock nut. Overtorquing the nut will just distort the adjuster threads and make future adjustments more difficult if not impossible.

Forgive me for droning on. Perhaps this will be of help to some new RX-3 owners.

[CSCDude]

Originally Posted by NoVa Rider

We all know that the RX-3 uses screw and lock-nut adjusters to set valve clearance. This is one of the features that makes the bike owner-serviceable, since you don't need a set of shims and you don't need to demount the cam shaft to adjust valve clearance.

Many of you are already well familiar with adjusting valves. But I thought I would share a few tricks I picked up adjusting valves on hundreds of air-cooled VWs, along with many motorcycles, over the years. If you know how to do it, no need to read further.

I have not yet received my RX-3, so these are general instructions. CSC's tutorial covers the specifics of removing body work, loosening the radiator mounts, removing the valve cover, and setting the engine to the correct position.

Once you have the valve cover off and are ready to measure, its always helpful to make sure the adjusters have some free play in them. You should be able to hold on to the adjuster or even just put you finger on it and wiggle it a bit. If you can't feel any freeplay, you may have the motor in the wrong position. If the motor is in the correct position, you should be able to wiggle all the adjusters.

Next is inserting the feeler gauge. Depends on how much room you have. You may have difficulty simply pushing the gauge between the adjuster and the valve stem; but often you can insert the blade of the gauge into the space beside the rocker, and then draw the blade back while gently pushing it into the gap. We'll see how much room we really have in the RX-3 to see if further tricks may be necessary.

But if you can't get the blade into the gap no matter what you do, the adjustment may be too tight. Try a thinner gauge just to be sure you are doing it correctly, and to measure what the adjuster is actually set at, just for grins.

So you have the correct gauge in place. If adjusted correctly, you should feel a drag while drawing it straight backwards from the gap. The gauge may tend to buckle if you try to push it further in, but if you can draw it back without having difficulty holding onto the gauge, you are OK. If you feel no drag, and you're sure the blade is in the gap, the setting is too loose and you need to adjust.

So if you have followed me this far, here are the real secrets. You would think that the adjustment is done by loosening the lock nut, perhaps loosening the adjustment screw a bit to get the guage in place, then turning the adjustment screw until you have the correct drag on the gauge, and retightening the lock nut. Well, not so fast.

Two things can happen when you try to tighten the lock nut. The first is that the nut can "drag" the adjuster with it as you tighten it, so you end up with a setting that's too tight. The second thing is a bit more subtle. When you tighten the lock nut, presuming the adjuster doesn't "drag" with the nut, the nut actually draws the adjuster up slightly against the threads as its tightened. This actually increases the gap a bit.

The solution? First, set the adjuster so its a bit tighter that you would like. So that you can just barely pull the gauge back. Then, put your wrench on the lock nut, and set your screwdriver in the adjuster slot. As you tighten the lock nut, apply slight "back pressure" on the adjuster. Not enough to turn the adjuster, just enough to keep it from being "dragged" by the lock nut. Then, since you started with setting a bit tighter that you wanted, as you tighten the nut, you should find the adjustment loosens just a bit.

At this point, DO NOT TO OVERTIGHTEN THE LOCK NUT. Particularly on a small nut/adjuster arrangement like the RX-3, it does not take a lot of torque to secure the lock nut. Overtorquing the nut will just distort the adjuster threads and make future adjustments more difficult if not impossible.

Forgive me for droning on. Perhaps this will be of help to some new RX-3 owners.

That was the best explanation I've ever read on the nuances of getting a valve adjustment right. Well done.

[G19Tony]

0330 departure in the truck. I like a nice road trip once in a while. I also like the dawn patrol. If I can get past the construction on 15 with no problem, I should hit CSC around 0730. In time to grab a quick McMuffin before they open. I called today, all the paperwork is ready!

I found out the other day that the manual is on CD. That didn't occur to me. I thought it would be printed. Does anyone know if it will work on IOS? The manual for my BMW is on CD. It doesn't work on IOS.

Anyway. I'm jazzed to make the run and excited to get the bike!

[SpudRider]

Originally Posted by CSCDude

That was the best explanation I've ever read on the nuances of getting a valve adjustment right. Well done.

I agree; you did an excellent job.

I would only add one point. After you are done adjusting all the valves, turn the engine several revolutions, and verify the valve lash is correct. Once again, you will know you are at the correct position of top-dead-center on the compression stroke if you can feel some wiggle in all the valve tappets.

[SpudRider]

Originally Posted by G19Tony

0330 departure in the truck. I like a nice road trip once in a while. I also like the dawn patrol. If I can get past the construction on 15 with no problem, I should hit CSC around 0730. In time to grab a quick McMuffin before they open. I called today, all the paperwork is ready!

I found out the other day that the manual is on CD. That didn't occur to me. I thought it would be printed. Does anyone know if it will work on IOS? The manual for my BMW is on CD. It doesn't work on IOS.

Anyway. I'm jazzed to make the run and excited to get the bike!

Good for you, Tony. If you have time, please take some photographs of the CSC building, your loaded trailer, et cetera. We love photos.

[oldqwerty]

Originally Posted by CSCDude

That was the best explanation I've ever read on the nuances of getting a valve adjustment right. Well done.

Sometimes the issue is the bend in the leaf. I have a set of feeler gauges that have prebent leafs riveted to thicker handles that will enter the access hole between the adjustment screws and not need to be bent to clear the head. I wonder if these are still available anywhere. Try to bend the leaves of most feeler gauges and they break. As I recall, they weren't cheap but they sure made screw adjusters easy to do.

[Weldangrind]

Originally Posted by G19Tony

0330 departure in the truck. I like a nice road trip once in a while. I also like the dawn patrol. If I can get past the construction on 15 with no problem, I should hit CSC around 0730. In time to grab a quick McMuffin before they open. I called today, all the paperwork is ready!

I found out the other day that the manual is on CD. That didn't occur to me. I thought it would be printed. Does anyone know if it will work on IOS? The manual for my BMW is on CD. It doesn't work on IOS.

Anyway. I'm jazzed to make the run and excited to get the bike!

If it doesn't work on IOS, I bet you could give it to a print shop and ask them to make a hard copy for you.

[SpudRider]

Originally Posted by oldqwerty

Sometimes the issue is the bend in the leaf. I have a set of feeler gauges that have prebent leafs riveted to thicker handles that will enter the access hole between the adjustment screws and not need to be bent to clear the head. I wonder if these are still available anywhere. Try to bend the leaves of most feeler gauges and they break. As I recall, they weren't cheap but they sure made screw adjusters easy to do.

The valve lash specifications for the RX3 are very small.

0.04 mm = 0.00157 inch
0.06 mm = 0.00236 inch

Feeler gauges this size are so flexible I don't think a slight curve in the feeler gauge will adversely affect the measurement.



However, if one desires, feeler gauges this thin are also very easy to bend without breaking.

The 32-piece, feeler gauge set sold at Harbor Freight does go as small as 0.04 mm.

http://www.harborfreight.com/32-piec...uge-32214.html

[katflap]

Thanks to Joe/CSC and No Va Rider for the excellent tutorial and tips.

The job is now done

I went with the idea of setting it at 0.06mm (to a good fit), then after tightening I tried 0.04mm (this was a loose fit)
and then tried 0.08mm , this I couldn't get in the gap at all. So it certainly won't be too
tight and at worst it will be with about 0.07mm of slack.

The end result - sounds a little more "tappety" than before but I'm good with that.

The bike rides fine, no noticeable difference.

[katflap]

Originally Posted by SpudRider

Did you release much pressure when you unhooked the fuel filter from the fuel pump? I assume any leaking fuel is the result of the pressurized fuel line, and the leaking will stop after the pressure is vented. If so, you can tilt the fuel tank more horizontally, and no more fuel will leak from the hose.

According to the CSC tutorial, you can get more working space to adjust the valves by loosening the radiator mounts. You don't need to drain the coolant, or disconnect any of the hoses.

http://californiascooterco.com/blog/?p=14703

Are the radiators, the coolant hoses, or both, blocking access to the exhaust valve tappets? Do you plan to work from above, or from the front, left side of the bike to adjust the exhaust valves?

I didn't notice any pressure in the fuel line but the bike had been switch off for some time before I released the fuel line joint. It was more of a dribble. When I put the tank back on the bike some fuel started to flow again

Here's a pic of me at the exhaust valves. I did them from this position.

Yellow arrow - radiator pushed out of the way as far as poss.
Red arrow - is my lamp for a bit of extra light