Dyno time and speedo?

[morepower]

Ok so I had my bike on the Dyno at RJS. They ran the bike up for me after it being stood since January at least and the carbs were caked in crap.

So here is the question how much difference is there when you drive the speedo cable to get the needle up above the optical sensor. Does not having the speedo moving limit power and alter the jetting needed,?

[mellorp]

Hopefully you have read all of this

http://www.tzr3ma.com/index.html

[morepower]

I did see where he said it was in a safe PV curve when you start up the bike and this curve kicks in again over 180kph.But if the dyno operator cannot spin the cable to put it into the other curve how much difference will it make? That's the thing. I know it does but how much impact will it have in the real world. Lol

[Warwick]

In short, if the ignition is stock and the restrictor unit is in place, you would expect to see the dyno curve hit a bit of a bit of a brick wall and drop off very sharply. If you stick a battery power drill on the wheel end of the speedo cable and lift the speedo a bit (only do this after you have started the bike), you should see a noticeably more rounded power curve - and a smidge more power. Jetting shouldn't really be an issue if it's stock-ish. Curves should look something along the lines of below - but lower numbers if it's stock.

[morepower]

Cool, thats all I need to know really. I am not expecting a 10bhp gain or anything its just knowing that if I take it out on track it will be OK with the setup in the bike now.  Robs dyno is not generous compared to some so not worried about the numbers at the moment. Any gain I find in the future will be on the same dyno. I just dont want to blow it up before I get to do anything to the bike... Lol

[morepower]

So I got the bike back yesterday and a dyno sheet too.. The jetting was 190/195 mains with the air box restriction removed so as I had checked the mains before it went to have the carbs ultrasonically cleaned and serviced I knew with those mains it would be too lean.  The baseline run confirmed it and the jetting ended up at 300 mains so the bike is now less likely to go pop and I now feel happy to take it to Mallory Next week if the weather is OK.. It is down on power from what most have said it should have so that could be it needs rings or rings and pistons?? It could also be the dyno is not generous as I know Rob at RJS is well respected and is not known for giving big numbers to customers. It topped out at 47.3BHP which, for aftermarket pipes (Alpha racing are supposed to be quite good) and the air box restrictions have been removed, may be low but it is also the first actual 3MA I have that I can use as the black one is still waiting for paint. Not sure if I have missed anything??? But I took it for a quick spin and if you give it full throttle below 6000 to 6500rpm it stutters and feels horrible until it comes on the pipe at about 7500rpm then it clears. Roll the throttle on and it feels fine. I will do some more work on the bike over winter as the Black bike will not get the bodywork back until March.. I think it could be stronger as it does rev through to 11,500rpm fine and has some over rev to 12,000rpm if needed it just feels a little down on power. 

[Warwick]

It'd probably be more useful to get a reading against rpm rather than wheel speed so you can check where the power is peaking if that's possible?

[morepower]

I just handed the bike over to get it sorted and running.. I will get it run up again and get Rob to hook up the RPM, but do want to get out and run it before it gets too cold and the track is greasy.. I will have the NSR with me too and do a back to back lap time comparison..

I now want to know what length the dog bones are as I have some quad link dog bones from Projection Components to fit and speed up the steering..