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bultaco

WR400f starting issues

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I took my bike to reputable mechanic to see if he could get her to start more easily. He checked my work in putting in a Hot Cams exhaust cam (with auto decompression). He mentioned that it all seemed fine, valve clearances...yet he moved the cam just one link for I think 12 pins total between cams. He says it starts a little better. He also went through the carb....all good...all new jets, aftermarket ap squirt unit, gaskets...just that the pilot is a 48 not 45 as stock calls for...Bike has White Bros. aftermarket exhaust and free mods...grey wire cut, airbox opened, throttle top out.

Is there anything else to check? This is quite frustrating. CDI unit, compression, kill button not quite right? UUUUKKKKKKKKK

Any suggestions appreciated:worthy:

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I'm on the same position right now everything mechaniclly seems to be ok so I was told it's electrical the problem weather it could be the kill switch being shorting out or it's broken the wire at some point, also maybe the spark ot could be weak so it could be the coil itself or the stator not producing enoug juice to help out well that's what I was told and haven't got a chance to check it yet

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Pull the plug and ground it against the engine, kick the bike over. You should see a healthy spark. This will let you know if the problem is with your spark or your carb. Most people twist the throttle on the 400's two or three times before kicking over the bike. This activates the accelorator pump for extra fuel during starting. The 400's are getting old enough to have lots of AP issues. If your problem is with the carb, pull the carb and check the AP work-a-tude. It should spray a health stream of fuel into the engine. If not, try the O-ring mod. If that doesn't work, there's probably a clog in the system somewhere. I had to dig way far into a WR400 AP system last summer to get it to work. There are two one-way valves in the circuit. The second one was clogged. Good luck.

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