> Eric Migliorino Wrote:
> How did you break in the Polini kit? The manual states not to go over
> 3/4 throttle the first 500km which is a little over 300miles. Seems
> sort of excessive but maybe I’m wrong?
To break in the kit I just let it heat cycle a few times. Fire the bike up, let it idle, get up in temp to around 180*F, then shut it off. I did that maybe 3 times. For the few days after that id take it around the block, more or less lugging it, keeping the bike under 15mph. After a couple days of cruising around the neighborhood I took it along the beach after work every other day (25mph speed limit) and ran it from 15 to 25mph trying to vary the speed. You're right the break in period is 500-600km I don't remember which. It seems the kit gets more powerful with every ride, and the cylinder head temps have dropped almost 20*F since installing.
> Are you getting mid 30’s with the tiny LB50 stock carb??? I couldn’t
> get my LB50 to work well with the stock LB50 carb, Polini kit and MLM
> pipe combo. Didn’t spend much time trying to re-jet and time since I
> had an LB80 carb I knew I put in it.
Yes that speed is with the stock LB50 carb, Polini kit, "hi compression head" and a modified stock pipe. I have to go back and look through this thread but I believe I settled with a 72 Jet. It's maybe a little on the rich side by a jet size or two, sustained wide open pulls will never go above 330*F. The Chinese PW80 clone carb I got yesterday from amazon measures 15.2mm in the center of the Venturi. The slide measures a hair over 17mm so I have room to open it up and not bleed around the slide which is what Im going to do this weekend. I was hoping this carb would have a throat closer to the 19mm stock LB80 carb, but 17mm will have to do for now until I can get ahold of an LB80 carb or a clone carb with a bigger throat. 15 to 17mm is a good start anyways, almost a 30% increase in area. That would work out to a nice boost in performance assuming the velocity in the Venturi doesn't fall off at low speed. We will see. I will report back here and on youtube with any findings, I'm most interested in boosting acceleration.
> Let us know how the PW80 carb works out. Does the stock carb/frame
> cover work with it? Did you need to re-jet? It should come with a 120
> main jet. I have an older LB80 carb up-jetted to a 95 jet in mine with
> the Polini kit. And when I say older style, it’s the LB80 carb that
> comes stock with a 65 main jet and has the single black plastic float.
Im not sure yet but my first impressions would say yes it fits under the plastic trim. Thats my top concern. I would have splurged on the VM20 intake and carb but I want to keep it mostly stock appearing. My clone carb jet isn't marked but I will post final jet size (micro bit size) when I settle on one.
> Are you keeping the oil pump hooked up or running premix? I was
> thinking of pairing a PW80 carb with the PW80 oil pump, thinking the gas
> to oil output we be in line with what the Yamaha engineers originally
Im still running the stock injection pump with yamalube 2S. Judging by smoke alone, this pump is more than adequate for this application. Like I said above cylinder head temperatures are relatively low during sustained wide open pulls. It appears from both my Chappys, the bikes are over oiled. Its my understanding Yamaha squirted a little extra dinosaur juice to ensure a long healthy life.