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A non repeatable top end speed could be due to many variables.

Way back in '85 I raced the Bonneville Salt Flats on a 1000 cc Honda Interceptor on the 5 mile course. I made 3 runs that were timed to the 1/1000th of a MPH, 3 decimal places to the right. My speeds varied by 6 mph on these three runs for top speed. My best was 148.514 MPH. These 3 runs were made within an hour, same temperature, same surface, likely same calm or wind. As speeds increase, the likelihood of repeatability diminishes even further.

Re your valve lash, check them all. Setting them to the smaller side of the spec will give you maximum cam duration opening the valves the longest, yielding the most potential power. Having a precision 3 or up to 5 angle precision valve job may help you beyond stock and freshen up a seal. Also bead blasting the chambers and valves will help and smoothing the seat to port interfaces can help as well without doing a full blown porting job.
 

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Discussion Starter · #7 ·
A non repeatable top end speed could be due to many variables.

Way back in '85 I raced the Bonneville Salt Flats on a 1000 cc Honda Interceptor on the 5 mile course. I made 3 runs that were timed to the 1/1000th of a MPH, 3 decimal places to the right. My speeds varied by 6 mph on these three runs for top speed. My best was 148.514 MPH. These 3 runs were made within an hour, same temperature, same surface, likely same calm or wind. As speeds increase, the likelihood of repeatability diminishes even further.

Re your valve lash, check them all. Setting them to the smaller side of the spec will give you maximum cam duration opening the valves the longest, yielding the most potential power. Having a precision 3 or up to 5 angle precision valve job may help you beyond stock and freshen up a seal. Also bead blasting the chambers and valves will help and smoothing the seat to port interfaces can help as well without doing a full blown porting job.
So it’s not an issue if a non repeatable top speed. I’ve made 100’s of runs of data. She’s not pulling at the top end 13.5k-14.5k anymore like she used too. Also all gearing, tire size, all these things have been eliminated as a cause. Extensive data on all this.
 

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A non repeatable top end speed could be due to many variables.

Way back in '85 I raced the Bonneville Salt Flats on a 1000 cc Honda Interceptor on the 5 mile course. I made 3 runs that were timed to the 1/1000th of a MPH, 3 decimal places to the right. My speeds varied by 6 mph on these three runs for top speed. My best was 148.514 MPH. These 3 runs were made within an hour, same temperature, same surface, likely same calm or wind. As speeds increase, the likelihood of repeatability diminishes even further.

Re your valve lash, check them all. Setting them to the smaller side of the spec will give you maximum cam duration opening the valves the longest, yielding the most potential power. Having a precision 3 or up to 5 angle precision valve job may help you beyond stock and freshen up a seal. Also bead blasting the chambers and valves will help and smoothing the seat to port interfaces can help as well without doing a full blown porting job.
DO NOT EVER BEAD BLAST TITANIUM VALVES.
DO NOT LAP THEM EITHER - just clean them with contact cleaner and light scotch brite.

jason
 

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Discussion Starter · #10 ·
Funny seeing you here. Since I just picked up the gixxer you built for Chris yesterday if it doesn't get up to 207 in the text next week do I get a refund? Just wondering? :)
I built? Must have the wrong guy. Cause if I’m asking for knowledge on adjusting valve clearances. I definitely am not building bikes for people, unless it’s advice on my set up and modifications.
And 207 was the highest ever. Average around 204.
 
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