[scupper660]

Ok guys i have a strange one i have an 05 660 with a fully built 686, 13-1 comp, ported head with dual titanium springs, stage 3 camshaft, rossier full exhaust system, air box kit, bike was tuned on the dyno at trinity, it had 13-40 stock gearing and in 5th gear it would lay over and slow down like a speed limiter not like a rev limiter, this weekend i went to a 14-40 gear and it is very fast threw 1-3 gears and into 4th then about half way threw 4th it slows down again and you put it into 5th gear it acts like the motor is shutting down ?, let off the throttle for a few second then back in it pulls hard again and shuts down like a speed limiter again ? does this thing have some type of speed limiter ? any ideas would be great i am starting to get really bummed out with it. Thanks B

 

[akawilliam]

Some body will help you out here due to my lack of knowledge i cant answer you. You said "bike was tuned on the dyno at trinity" They could`nt answer your question are tell you what was up? Did they do the engine for you? I assume your talking about Trinity racing if so you must live close to them. They should know what is wrong.
Sounds like you have a nice set up I will follow this thread to watch and see what happens. Im sure maddog and others will be commenting very soon. Best of luck

 

[Mad Dog]

If it's not your parking brake/reverse rev limiter then it's almost certainly your carbs/intake. It's possible that you've got poor jetting (not as likely if you had it dyno tuned), a leak in your intake, dirty/clogged fuel pathway, damaged diaphram, or the like.

I have no idea what the actual specs are of the bike, but there's always the chance that if you've got huge jets in there and it's still lean up top then you've surpassed the flow capability of the oem carbs. This isn't terribly likely but it's a thought.