I appreciate that. If the bike had shown any signs of trouble I would've had it fixed before I sold it. I'm glad it will be cheap to fix.

I can easily blow through the filter (RX3 and RX4 have the same filter). Unless the element is plugged up the filter should pass the required fuel easily. We are not talking about moving a lot of liquid, only about 1 gallon per hour.

Glad to hear it's most likely a cheap fix. I would definitely recheck those valve adjustments though.

I've already checked and re-checked the valves. Will do a leakdown test just to be certain.

Charles.

Leak down test is worthless on a bike with aN automatic compression release. My filter still hadn’t arrived this morning, and I had the day off... but my fuel fittings from amazon did. So I made a bypass line and buttoned it all back up and went out for a two hour ride. I included all different terrain, including highway. I reached 87mph on the speedo (79mph actual) and that tells me the engine is perfectly fine!

Russel, you couldn’t have known the filter would start coming apart internally. It’s a bit of a design flaw, the filter is at the lowest point in the fuel system, and when a bike sits for a long time that’s where any water ends up.

I appear to be good to go. And low and behold my filter arrived. So now I can take the tank back apart and replace my bypass line.

Charles.

Glad it all turned out to the good. Now you can enjoy some riding. Run ethanol free fuel will save you a lot of headaches down the road.

That's good to hear.

Any CR design should be 'dynamic', cutting out when rpms get higher than xxx. With all the parts static, a leakdown test should be doable without any problem.
If you are at TDC, and have a CR leaking out the gases... it would be counter-productive at all rpms though less noticeable at high rpms. Most CR mechanisms use a bump on a cam lobe, or a movable interruptor, neither of which should be doing anything at static TDC.
Please explain how the CR works such that it would make a leakdown test unpossible? I have no mental picture that would explain.
Did you get an el-cheapo lipstick(?) camera to connect to a laptop PC and shove down a spark plug hole? They are less than $15 on DaRiver or DaBay. I have used one to inspect cylinder walls. I would be concerned that the lean condition did some damage to the piston crown. It MAY have eroded some of the metal around the perimeter. I have seen that happen on engines that got too hot. Most were air cooled, which seems to indicate they are more susceptible, but I wouldn't make any bets.
One last thought is that extra fuel that makes its way to a catalytic converter can cause the converter to glow cherry red. You would get a lot of sparkage if that occurred while turning 9k.

tom

This... leakdown is the answer to having a compression release, which skews a compression test. I do leakdown tests on ACR equipped motors every week...

Just wanted to add also that if you are using a low-cost compression test gauge, you may want to give a better gauge a chance. The low cost items don't seem to work too well on small displacement engines. Either the internal mechanism is too 'rough' and does not respond to small volumes, or the mechanism is too 'loose', and again doesn't respond properly. A larger piston/cylinder can flow a lot more air into the tubing and gauge than a smaller and still have a 'good' reading(at least for comparison to other cylinders), while a small displacement would be giving up a lot of its volume to the rubber tubing and gauge gizzards(relatively).
I bought one from -bay, and it read ~30psi, and when I used my old(~50) JC Whitney gauge, it read 75+ from memory. I got a refund for the low-cost unit.
tom