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Discussion Starter · #1 ·
This set up is on a newer built 686, Stage 1 cam, 11:1 compression, factory carbs.

Current set up: 180-185 mains.. 27 pilots..Alba needles…2 ¾ turns on idle air screw. No air box and pro design filter


Ok here is my issue. The motor runs great when riding conservatively, but after a hard full throttle pass it wants do die at idle to quarter throttle….give it full throttle and it runs great, coast and it wants to die and runs real rough.

I was trying to tune it for the third day and when the sun went down and it began running rough, I was feathering the throttle to keep it running and it was shooting pretty large flames out the pipes.

I’ve checked for vacuum leaks and every thing looks good, adjusted the valves and it starts right up…it just freaks out after hard full throttle….like some how its flooding??? Let it die…wait a few moments, start it back up and runs good till another hard pass.


Any help….any at all would be great…I am starting to go nuts

Thanks AJ
 

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Master of the Electron
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Run your idle FUEL screws (not air screw - they're on 2 strokes) down to around 2 turns and see if it gets any better. I think your pilot jets may be a bit too large - turning in the fuel screws will valve this down a bit.
 

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Discussion Starter · #3 ·
I had 25 pilots in with the fuel screws out 2 1/2 turns...and was having the same issue, but the intake valves were a little on the tight side. I adjusted the valves and put the 27's in at that point.
 

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Yah ur jetting is off for sure
 

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I am unique
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This set up is on a newer built 686, Stage 1 cam, 11:1 compression, factory carbs.

Current set up: 180-185 mains.. 27 pilots..Alba needles…2 ¾ turns on idle air screw. No air box and pro design filter


Ok here is my issue. The motor runs great when riding conservatively, but after a hard full throttle pass it wants do die at idle to quarter throttle….give it full throttle and it runs great, coast and it wants to die and runs real rough.

I was trying to tune it for the third day and when the sun went down and it began running rough, I was feathering the throttle to keep it running and it was shooting pretty large flames out the pipes.

I’ve checked for vacuum leaks and every thing looks good, adjusted the valves and it starts right up…it just freaks out after hard full throttle….like some how its flooding??? Let it die…wait a few moments, start it back up and runs good till another hard pass.


Any help….any at all would be great…I am starting to go nuts

Thanks AJ
Try #25 pilots...........fuel screws at about 1.5 to 2 turns............
Needles half way up........
160 and 165 mains mikuni style......................
 

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This set up is on a newer built 686, Stage 1 cam, 11:1 compression, factory carbs.

Current set up: 180-185 mains.. 27 pilots..Alba needles…2 ¾ turns on idle air screw. No air box and pro design filter


Ok here is my issue. The motor runs great when riding conservatively, but after a hard full throttle pass it wants do die at idle to quarter throttle….give it full throttle and it runs great, coast and it wants to die and runs real rough.

I was trying to tune it for the third day and when the sun went down and it began running rough, I was feathering the throttle to keep it running and it was shooting pretty large flames out the pipes.

I’ve checked for vacuum leaks and every thing looks good, adjusted the valves and it starts right up…it just freaks out after hard full throttle….like some how its flooding??? Let it die…wait a few moments, start it back up and runs good till another hard pass.


Any help….any at all would be great…I am starting to go nuts

Thanks AJ
Any port work?

Nate
Alba Racing
 

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Going to a 686 usually doesnt effect jetting much. If there is no port work a good starting point would be:

160R/155L mains
27.5 pilots
Our needles on the 4th clip
1.5 turns on screw

Nate
Alba Racing
 

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Discussion Starter · #9 ·
No port work done.

I know the jet numbers doo seem real high to me also, whats strange is that the plug is dry and if anything looke on the lean side.

I will change out the jets as you guys suggest, and again thanks for the help!
 

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Master of the Electron
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Hey Nate - are you in Poway? What happened to the store there?
 
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