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View Full Version : Bike dies after a sudden stop


Billy Mild
2014-03-30, 06:11 PM
Bike: 1971 Yamaha AT1-c
Mods: K&N filter, GYT Kit pipe with a DG universal silencer, 180 Main Jet, 35 Pilot Jet, 2.0 Turns out on the Air screw

I'm trying to get my bike running 100% before I continue doing anything else.

My current issue is my bike will die after a sudden stop. I originally had a 30 pilot jet. I had to have the air screw all the way screwed in to be able to take off from a stop. If I had it even .5 turns out it would just bog really bad. I stepped up the pilot jet. I put in a 35 pilot jet. The bike idles fine even after it is warmed up. My road test for the most part went fine. My only issue right now is sudden stops. The bike will die after a sudden stop. If I go WOT from 40 MPH to a dead stop, the engine RPM's just keep falling until the point it dies out. I tried to raise the idle a little bit, but it seems to idle fast when just sitting at a stop.

Any suggestions? Could it be timing?

TheRoach
2014-03-31, 08:20 PM
Bike: 1971 Yamaha AT1-c
Mods: K&N filter, GYT Kit pipe with a DG universal silencer, 180 Main Jet, 35 Pilot Jet, 2.0 Turns out on the Air screw

I'm trying to get my bike running 100% before I continue doing anything else.

My current issue is my bike will die after a sudden stop. I originally had a 30 pilot jet. I had to have the air screw all the way screwed in to be able to take off from a stop. If I had it even .5 turns out it would just bog really bad. I stepped up the pilot jet. I put in a 35 pilot jet. The bike idles fine even after it is warmed up. My road test for the most part went fine. My only issue right now is sudden stops. The bike will die after a sudden stop. If I go WOT from 40 MPH to a dead stop, the engine RPM's just keep falling until the point it dies out. I tried to raise the idle a little bit, but it seems to idle fast when just sitting at a stop.

Any suggestions? Could it be timing?

More than likely a carb issues... My old 12R had this problem. It even bogged when I got on it sometimes. I started with plugs, coils and wires, then went to idle adjustments. Nothing helped. Turned out it was carb issues. Cleaned them up and ran like a champ.

Jefferson
2014-12-15, 08:57 PM
I know this has been awhile, but I think your issue is a float level set too high. On hard stops the fuel is sloshing up into the intake tract and drowning the engine