So I have a Senna and Tambo, but I have not been riding the Senna because the Tambo is so well setup for me (suspension etc) one of the other things is it feels so much more powerful than the Senna even though on paper it only has a couple extra ponies and torques.

I think I want to swap out the rear sprocket on the Senna, any suggestions here? I don't need a bike that goes 185 MPH so I am ok losing some top end to get some more power out of her.

And my second question is has anyone had an issue were the speedo jumps all over the place? is it a pickup problem or can someone point me in the right place to look? I'll be going about 40 and hit a bump in the road and it starts jumping all over 2-18-9-32-40-40-40-40-31-1-6.... Crazy!

Thanks In advance on both Q's

Hi ESP, I can't help you with the speedo issue - spooky! - but recommend an aftermarket sprocket carrier such as Talon for the back end. The carrier costs a bit, but after that, you can buy the sprockets cheap enough, so you can chop and change as much as you want until you find the right combination for you. I'd suggest just going one or two extra teeth on the back, but see how you go. They are easy to fit too, so you can run a smaller rear sprocket if you go touring etc. The one thing I will say is that changing rear sprockets will effect your speedo calibration, but until you get your speedo sorted, that probably won't be an issue. All the best.

Thanks for the advice, i think I might go up two teeth at first to see how it does, I can't imagine I would need more.

Funny the spedo will need to be recalibrated since it's not working right anyway!!! I hope someone has seen that before, or can point me in the right direction to check it out. Man I love my Tamburini I want to get the Senna closer to it.

other option on sprockets is to drop the front by 1 tooth

most people used to do it to the sp1 (rc51) in the uk to help fueling did it to mine
increases acceleration for a slight loss in top end
also less adjustment needed on the chain as 2 teeth on the rear make s the sprocket quite a bit smaller
but 1 tooth on the front sprocket size very slightly smaller as its small already

yes a speedo recalibrater will be needed depending on how much milage you do tho

I've heard this can cause more chain wear than the rear sprocket? should I also look at going to a different chain?


I hope someone can help on the spedo issue

With the speedo... it only glitches when you hit a bump so something has to be loose. I'd check the plug that runs into your speedo pick-up and make sure it has a good conection. If that all looks good then it's time to head for the speedo itself. This will require the removal of all your front plastic. You can remove just the front headlight piece but if it's your first time, I'd take it all off to be safe. Once you get the plastic and the covers out of the way, the first place I'd go to is the main plug at the bottom of the rear of the speedo. Then check all connections under the covers. If that looks good then you may have to start proding wires to find out whats going on (and that's a job for better men than me to figure out). Or it could just be a glitch in your speedo itself and may require a new unit........ TRY PUTTING ANOTHER SPEEDO INTO THE BIKE TO SEE IF IT'S A SPEEDO PROBLEM OR IF IT'S MACHINE SPECIFIC.

Good luck

I have the same problem with my bike at the moment regarding the speedo. It jumps from the correct speed to 0-4-8-2.... and then back to the correct speed. I have a new speedo sensor ordered as thats what my local mechanic said was needed.
I think I remember someone commenting that they were on there 3rd sensor! So Im guessing you have the same problem as me.

Hey ESP

I had the same speedo issue with my Tam...loose connector (For me at least) had it sorted with my last service, just wait til you take the bike in for service and add to the list. One front tooth worked well for me...just get a new D.I.D. chain, if you need to shorten (which I don't think you will) A good suspension set up from a pro (front & back) will make a world of diff in the handling of your senna.

The Tam has more torque than the Senna, I've ridden both back to back several times...I think that's what you're feeling.

How was your bike school exp?

Yeah the Tambo on paper does not look that much more than the standard F4 motor (in the Senna) but I feel it in the seat quite a bit, so I bet it is the Torque.

I think changing the gearing will help and I don't need to go 180mph anyway.

Thank you for asking about my racing school, actually I have a post about it here, check it out: http://www.mvagusta.net/forum/showth...light=schwantz

It was really great

On a side note I was happy to finally get my plates in for the MV's I got 5enna and Tambu.

ESP, I had the same issue as well with my 06 F4S speedo jumping around like that. But I also had the blipping issue below 3k rpm after warm up. After warranty work was completed on fixing the blipping issue, ironically the speedo issue was fixed as well. They replaced the wiring harness on mine due to a bad ground. So, you might want to check the grounds as well.