Can't start 850 Commando

Joined
May 31, 2004
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1
Maybe you folks can help with some troubleshooting. The bike is a 74 with re-sleeved carbs and electronic ignition. Ran great in 2002. Wasn't used in 2003, though fuel additive and oil change were handled. This year, it's been difficult to start. Actually, right now it won't start. Got it fired up a week ago -- after a lot of tickling of the carbs -- and when warm it ran great. Now, nothing. It fires for a split second at most. Choke on, off, tickle the heck out of the carbs. Nothing. It has spark, the plugs are wet but not oily, though they are a little black. Bad fuel? Electronic gremlins? Gummed-up carbs? Any advice is appreciated. Thanks.

Jim
 

MichaelB

"Sons of Arthritus"
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The plugs are fouled. Clean or replace them. Drain fuel, replace with fresh.
Spark is easy to verify. Ground the plugs against the head before installing, kick it through easy to verify spark. Chances are you are O.K.
I only tickle carbs when cold for a 3 count. Just barely allowing fuel to dribble. I live on the west coast @ sea level and never use the choke. It usually will foul the plugs. I would suggest trying no choke.
Once it is running, if you cant' get it too smooth out with the pilot screws, your pilot jet is probably clogged, this happens from sitting.
You can depot them, soak em and reassemble.
Or try this. Screw the pilot screws in 1/2 turn at a time till they bottom, to get a starting point. They should be about 3 1/2 turns. Remove the screws. Source a piece of 12ga. multistrand copper wire, remove one strand. Feed the wire in the screw hole, poke around till you find the jet and you will feel the wire go further. If it is a minor clog, this will free it. It may need to be soaked first. But it is worth a try.
If you choose to remove them be careful upon reassembly. Be sure to reassemble carb completely with float bowl, slide and top before installing on to manifold. This will help to prevent distorting the carb body. Most people leave the slides/top attached to the cables on the bike. Then torgue the carb bodies to the manifolds without the tops/slides in place therby distorting the carb body. I have first hand experience about this!!
Start with 3 1/2 half turns on the pilot screw and have a go.
When syncing carbs with a Boyer, DO NOT unplug one cylinder at a time. The Boyer doesn't like this.
 
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