Help cannot get bike to stay runing

[Want2ride]

little background picked up a 1981 Yamaha 650 xs for 200 had not been run in two years new coil junkyard ignition box from a "running bike" new coil spark plugs and wires from mikesxs rebuilt and cleaned carbs replaced fuse box with ne'er style fuses ok the bike gets strong spark for first 2 or 3 seconds with electric start but after that nothing bike will try to start so I'm getting fuel but it will not spark with kick starter any thoughts or ideas are welcome and needed at my wits end here

 

[gggGary]

How good is the battery?
Check your grounds all over.
Which mikes coil? one of his coils is crap.
I think I will vote for a ground issue. be sure ground wires from frame to engine are in place, the engine mounts are not enough.

 

[Want2ride]

Brand new battery if I put in a new ground where should I put it?

 

[gggGary]

engine mounts up on the head is where the factory did it.

 

[Want2ride]

Figured it out was a bad TCI pick up and stator assembly got it to run but only on full choke so I'm pulling the carbs back off to see if I messed up the float levels when I rebuilt them thanks for the answers

 

[retiredgentleman]

Figured it out was a bad TCI pick up and stator assembly got it to run but only on full choke so I'm pulling the carbs back off to see if I messed up the float levels when I rebuilt them thanks for the answers

Only runs if choke fully open means the pilot circuit is not supplying enough fuel/air...................pilot jet blocked/pilot jet too small/mixture screw closed/pilot passage ways blocked with crap.

 

[Want2ride]

Thanks will look into that tonight when I pull the carbs but when I rebuilt them two weeks ago I boiled them in CLR and ran compressed air through every orifice I could find what is the proper adjustment on the pilot circuit?

 

[chizler62]

IMO, using a blow gun thru a jet or passage doesn't mean its clear. Especially the pilot itself. Use a needle off a wire brush thru each hole even the emulsion holes on the side and be certain you can blow contact or carb cleaner easily thru them. Don't over look the needle and seat valve assy, screen etc float height is very important also.

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[gggGary]

Well snap, I will guess you did not remove the butterflies and throttle shafts before you "boiled them in CLR" Were ALL the other jets, orifices, etc removed? Good chance you have destroyed the rubber throttle shaft seals. IIRC CLR is an acid with some other nasty stuff tossed in. I'm thinking boiling a carb body in that stuff would not ever be a good idea. Among other possible issues it may have leached away parts of any brass left in the carbs.

CLR Calcium Lime Remover ie Acid.

 

[Want2ride]

The CLR was very diluted have used this method before with good results got a lot of the gunk and varnish out and looked clean but not scoured will use some mechanics wire to clean the holes out thanks

 

[retiredgentleman]

Thanks will look into that tonight when I pull the carbs but when I rebuilt them two weeks ago I boiled them in CLR and ran compressed air through every orifice I could find what is the proper adjustment on the pilot circuit?

Look in the "Tech" section and find the Carb Guide. Read it very carefully until you understand how the pilot circuit works. There is a table for the various years of the carbs, which tell you what size pilot jet you should have and where to adjust the mixture screw. Start with the stock set up and adjust from there if you have changed the exhaust or air filters.

 

[Want2ride]

Got the bike up and running all last summer drained the fuel for the winter start it up first try this year the realized the low beam on the headlight was dim replaced bulb works great now but now it runs rough with the lights on low beam but turn it to high beam it runs perfect I have no idea how that happens any help would be welcomed