Help me figure out this no start I think i've done my due diligence with the forums and reading enough that I can ask. I'll start off with what I've done and what it has:

2007 that has sat untouched in a barn for around 5 years, 5200 miles
HMF exhaust and no airbox lid.
Bought a plastic fuel tank and new filters, lines
desmogged with vacuum caps


Carburetor was cleaned out thoroughly with carb cleaner and a wire. Bought a rebuild kit and replaced bowl gasket and jets and needle except the main jet
Drilled out the starter jet with a 0.05mm (0.0197")
Rebuild kit needle
Pilot jet: 35
Main jet: 130 (bike came like this, cleaned jet out and reused)
I have tried 1.5, 2, 2.5, 3, 3.5, 4 turns out on the idle screw


I have checked for spark and while I had the plug out and turning over, i saw fuel misting out of the hole. I have fuel and spark. However, when I look down in the hole it looks brown (normal) and crusty/textured like rust (not normal). The engine "thumps" as i turn it over, so I'm 50/50 on having compression. The engine has run on starter fluid for 5 seconds at most, but it is not consistent either. It ran once on its own gasoline supply, surged to 3k rpms, then wound down and died. Then zilch after that. I've tried choke in and choke out.

What do you guys think my next step should be? Try a #40 pilot? Buy a known working carburetor? I'm pretty stumped with this one. Kinda close to either buying a 3xx kit and a new carb, or hurling it into a lake!

 

Compression test. But the KACR (automatic compression release) can yield false low compression readings. Since it ran then fizzled, I think you need to know if it has decent compression.

.....you have a frustrating situation there.....

 

A wire will not reach all the way into passages. If it did, bike and auto shops wouldn't have carb washers. My recommendation still is to tear the carb down and have it cleaned in a carb washer or an ultrasonic cleaner for several hours. Sometimes we left them in for up to twelve hours sloshing around.

Then go to this page click here and look at the carb mods. You may or may not want to drill the slide.

If you get the cam cover off again and haven't done so, disable the compression release by removing the spring. It isn't needed since the kick start disappeared back in 2006.

 

First make sure the carb is getting fuel. ....cause it looks like you covered all the usual items.

 

Thanks all for the input. I'll disable the compression release, compression test, and decide from there. A chemical bath may be in my future. Will update with findings.

 

I will throw in one other option for cleaning that can be researched for validity. Pinesol soaking the carb. Seems some have had success using Pinesol, I think over in the ADVrider forum. The trick would be to rotate the carb around a lot to try to get the liquid into every possible port - what washers and ultra sonic cleaners do. Look it up, do some research. Maybe put it in a tub on top the washer or some other vibrating device for the cleaning process, Just a thought.

 

I have done the pinesol soak many times with great success.
Older carbs I do a 50/50 mix for 24 hours or so. Newer carbs I have used full strength over night.
Just dont put a plastic float in there, I have had one melt before.

 

I was looking at the Pine sol thing on ADV a year ago. Their formula has changed so on-the-shelf Pine sol is not the same as it used to be and may not do as well for a carb soak.
If you want the real stuff, Amazon may still have some of the original formula. I picked up a jug last year.

 

Back with an update! Did the compression test, got 50 psi throttle open. Uh-oh! Removed the KACR spring. Test again ... 50 psi again! Woohoo! Added oil to the spark plug hole. Instantly put out 150 psi. Looks like its time for a piston kit ...

Curently looking into the big bore kits. Doesn't really make sense to pay roughly the same amount of money for 250 cyl&piston when i can upgrade. addon: I just looked at the prices for the OEM 300 conversion. Yikes! Cyl+piston are 600 alone. Am I better off going aftermarket on this one? Eyeing up that 308 kit posted up on this forum.

 

Does sound like the rings are tired. More displacement is always a good thing.
I'd also suspect that your carb is still plugged up. Once you got it started on ether, the carb should have begun to handle fueling but it stalled. I've used the Pinesol soak on a pair of CVK's on a Triumph that had sat for years(needed a gas tank-to much crud) and they cleaned up with just compressed air.