rockstar81 Posted February 5, 2009 Share Posted February 5, 2009 I've got a xs400 that I can't seem to get the timing right to get it to fire off and run. I bought the thing as a basket case, rebuilt the top end of the motor and did some chopping to make a cool little chopper...well now it looks cool but don't run. The left cylinder will pop off and backfire thru the carbs, but the right side won't pop unless there's a good amount of carb cleaner in it's carb. I'm getting gas thru the carb and into both cylinders. I think I've got a major timing issue, but my manual isn't much for setting timing really well after a rebuild. I was wondering if there were any helpful hints or if I could switch the ignition over to something like a Boyer? Any help would be great. Thanks. Link to comment Share on other sites More sharing options...
Moderator drewpy Posted February 7, 2009 Moderator Share Posted February 7, 2009 I've got a xs400 that I can't seem to get the timing right to get it to fire off and run. I bought the thing as a basket case, rebuilt the top end of the motor and did some chopping to make a cool little chopper...well now it looks cool but don't run. The left cylinder will pop off and backfire thru the carbs, but the right side won't pop unless there's a good amount of carb cleaner in it's carb. I'm getting gas thru the carb and into both cylinders. I think I've got a major timing issue, but my manual isn't much for setting timing really well after a rebuild. I was wondering if there were any helpful hints or if I could switch the ignition over to something like a Boyer? Any help would be great. Thanks. the original contacts are fine and do work. you need to keep them flat and unpitted and correctly gapped. as for timing, use a xenon timing lamp and adjust each conatct plate to dial in the timing. the "flash" will freeze the indicator situated under the left hand timing cover on the timing mark. It does sound like carbs though, and they will either be gunged up with stale perol or may need balancing or float levels wrong. this has been discussed at length in other threads, feel free to do a search for them and to the forum Link to comment Share on other sites More sharing options...
rockstar81 Posted February 20, 2009 Author Share Posted February 20, 2009 Thanks drewpy... Got the bad boy up and running...now its not charging. Don't really know how to check the charging system componets to see if they're bad. Revving the engine will make the lights "brighten up" but it won't charge the battery while it's running. eBay's got a bunch of OEM regulator/rectifier combo deals...didn't know if that would cease or increase this headache. The bike is bare bones now, no turn signals, horn, speedo, etc...and all the wiring diagrams have all the extras I don't need, but from what I've seen I've got it wired correctly. I'm assuming it's a bad part. Any ideas? Link to comment Share on other sites More sharing options...
Moderator drewpy Posted February 20, 2009 Moderator Share Posted February 20, 2009 Thanks drewpy... Got the bad boy up and running...now its not charging. Don't really know how to check the charging system componets to see if they're bad. Revving the engine will make the lights "brighten up" but it won't charge the battery while it's running. eBay's got a bunch of OEM regulator/rectifier combo deals...didn't know if that would cease or increase this headache. The bike is bare bones now, no turn signals, horn, speedo, etc...and all the wiring diagrams have all the extras I don't need, but from what I've seen I've got it wired correctly. I'm assuming it's a bad part. Any ideas? stick a multimeter on dc volts across the battery terminals and you should get between 13.5 and 14.5 volts @ 3000rpm. for the charging system to work you NEED a good battery as it excites the field coil to generate the electricity. if after you have a good battery and you can't get the volts, it is usually the voltage regulator as they are electro mechanical in operation. drewps Link to comment Share on other sites More sharing options...
rockstar81 Posted February 24, 2009 Author Share Posted February 24, 2009 Sooo, tried all that, didn't get the voltage I needed. Is it a stator problem, or a regulator, or a rectifier, or just a little gremlin I don't know about? And, is there a way to switch to an electronic ignition--maybe one from a different year 400? I'm still trying to figure all this stuff out. Link to comment Share on other sites More sharing options...
Moderator drewpy Posted February 24, 2009 Moderator Share Posted February 24, 2009 Sooo, tried all that, didn't get the voltage I needed. Is it a stator problem, or a regulator, or a rectifier, or just a little gremlin I don't know about? And, is there a way to switch to an electronic ignition--maybe one from a different year 400? I'm still trying to figure all this stuff out. Usually voltage regulator problem, stator and field coil dont touch anything so are reliable. wires could crack where the drive chain flings oil on them though!! never disconnect battery when alternator is generating as it will fry! see other thread re: ignition Link to comment Share on other sites More sharing options...
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