Flat spot nearly kills the bike
#11
05-22-2013, 01:07 PM
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Your basic problem is too much fuel for the air passing through the motor.
Two ways to fix it
1. More air - IE free flow filter and free flow exhaust
2. Less fuel - IE smaller main jets
Basically the carb has three areas of operation
idle to around 2k is low speed jets
2k to around 4k is needle shape
4k and up is main jets
Your issue is 4k and above - it is fixed by throttling back and easing it through the flat spot.
Therefore the mains are too big.
remember that the middle two carbs run one size larger than the outer two because they run hotter.
Two ways to fix it
1. More air - IE free flow filter and free flow exhaust
2. Less fuel - IE smaller main jets
Basically the carb has three areas of operation
idle to around 2k is low speed jets
2k to around 4k is needle shape
4k and up is main jets
Your issue is 4k and above - it is fixed by throttling back and easing it through the flat spot.
Therefore the mains are too big.
remember that the middle two carbs run one size larger than the outer two because they run hotter.
#12
05-22-2013, 02:15 PM
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Ok guys update:
According to a gentleman I just got in touch with that does dyno's for bikes my jets were not right. So this is what I did cilinders 1&4 135 and 2&3 138. I got those jets from a friend and based on this guys knowledge f3's perform the best with that jetting set up. I did that and set the pilots at 1 3/4 out, put the D&D pipe back on and bike fired right up. I'm waiting for it to stop raining to see if it will hit a wall again or not cause as of right now the response on this thing in neutral is unreal.
According to a gentleman I just got in touch with that does dyno's for bikes my jets were not right. So this is what I did cilinders 1&4 135 and 2&3 138. I got those jets from a friend and based on this guys knowledge f3's perform the best with that jetting set up. I did that and set the pilots at 1 3/4 out, put the D&D pipe back on and bike fired right up. I'm waiting for it to stop raining to see if it will hit a wall again or not cause as of right now the response on this thing in neutral is unreal.
#13
05-22-2013, 04:30 PM
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Ok guys update:
According to a gentleman I just got in touch with that does dyno's for bikes my jets were not right. So this is what I did cilinders 1&4 135 and 2&3 138. I got those jets from a friend and based on this guys knowledge f3's perform the best with that jetting set up. I did that and set the pilots at 1 3/4 out, put the D&D pipe back on and bike fired right up. I'm waiting for it to stop raining to see if it will hit a wall again or not cause as of right now the response on this thing in neutral is unreal.
According to a gentleman I just got in touch with that does dyno's for bikes my jets were not right. So this is what I did cilinders 1&4 135 and 2&3 138. I got those jets from a friend and based on this guys knowledge f3's perform the best with that jetting set up. I did that and set the pilots at 1 3/4 out, put the D&D pipe back on and bike fired right up. I'm waiting for it to stop raining to see if it will hit a wall again or not cause as of right now the response on this thing in neutral is unreal.
The jets in the last but one post are wrong 138, 138, 138 , 135
What you have at 135, 138, 138, 135 sounds closer.
Hope the road run is what you expect.
Yes - when set up correctly the throttle response on the centre stand is real crisp.
#14
05-22-2013, 06:04 PM
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#15
05-22-2013, 06:41 PM
#16
05-22-2013, 11:28 PM
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Yep D shaped, I have the tool for it I got it at honda but many take them out with tiny long nose pliers and just cut them on top so you can fit a flat screwdriver in its real easy it can be done on the vise with a saw just go easy.
#17
05-23-2013, 03:54 AM
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So the crank case pressure was increasing the fuel pressure in the float chambers.
I had the correct diagnosis ( running too rich ) but the wrong cause.
Glad its sorted.
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