Trouble starting after sitting 6 months

[dryvr12]

I have an 83 xr200r which hasn't been ridden since Aug. I went to start it a couple months ago, but it would not start. I drained the old gas out of the carb and tank and let it sit until last night. The bike ran fine when I rode it in Aug. When I begin to kick it over it sounds like it wants to run, and sometimes will run for about a second. It dies whether I give it gas or not. The carbs were taken off and were spotless (only one ride since I last cleaned them). Pilot, main jet, & all the orifices were clean, and I have cleaned carbs before.

 

I poured a little gas into the cylinder and had a backfire or two. I cannot push start the bike. I may check to see that my timing is still correct, but I am getting frustrated. Other than changing out the old gas, nothing has changed on the bike. The bike was totally rebuilt ~ 2 years ago with less than 10 hours on it since.

[4strokeridertt]

Check the valves to see if you have a tight one. A tight valve may have a bit of oxidation on it and cause the compression to be down just a little.

[dryvr12]

Right before I went on the trip in august I put a new head gasket on which involved setting the timing & checking the valves among other things.

[jesus builtmy hotrod]

Do you use pump gas? Do they use an ethanol blend in Indiana, like they do in Illinois?

Ethanol gums up in carburetors real quick, the last bike I used ethanol in was a honda XL185. 1 kick to start if ridden every day, almost 10 kicks to start if it had been sitting for a week or two.

I cleaned the carburetor thoroughly, changed to 90 octane with no ethanol ($4.00+ per gallon, holy cow!), and the bike started on the first kick whether sitting for a day or a month.

Edited January 26, 2016 by jesus builtmy hotrod

[jjjrickey]

Pull the plug and hold it touching the head so there's a connection and look for a clean consistent spark. Might have to shut garage door and turn lights off in order to see it. If no spark then try a new plug.

I found with my xr100 that a "block heater" worked wonders when it was below say 40 degrees. I would set a space heater aimed at the cooling fins for an hour or so, until the the opposite side I was hearing was warm to the touch and the case had absorbed good heat. It was on an original 25yo piston, this would help it fire in a kick or two.

Edit: be careful with gas and electric heaters, also, the non ethanol gas as mentioned above is nearly a must for carbureted engines.

Edited January 27, 2016 by jjjrickey

[chadzu]

Double check that the pulse rotor is in the correct phase. You can install it 180* out and it will never start.

[dryvr12]

I set the air gap on the spark advancer to .012. I will check timing later today. Literally nothing has changed on the bike since I rode it last, not even its place in the garage.
Bike has always ran 87 grade pump gas, so that wouldn't be an issue.

[dryvr12]

Got her to run today. Seems the ignition timing had changed significantly since I last timed it. Fired right up in the ~ 30 degree garage.

[kirkallen143]

allright

Edited January 28, 2016 by kirkallen143