Dyno ChartsThis forum is for posting of your Dyno Charts. You will use a prefix to designate your Cubic Inches. When posting please include all model year, Cubic Inch and modifications in the thread title and in the body when posting your Dyno Charts.
Finally got my new to me FXR2 back from Rosa's Cycles on long island, NY. Took off the python 2:2s it came with and put on a Bassani Road Rage, a S&S stealth Air cleaner and a SE-3 cam. I know there are better cam choices, but I liked that it was drop in (uses orig. solid push rods) and it was very close specs to the Andrews EV27 many like.
The Dyno shop owner asked me what cam I had when I called on Friday checked on the status. He said it had a "dip" down low. He wasn't kidding. Now I did ride it today, and it does feel like it takes off like a turbo once you break 3krpms, and I can't really say it feels like it lost anything it had before I did the cam and pipe, so I'm not too concerned. but if I can do something to bump up that dip, I may, only because I like to cruise at around 2800.
Like I said, it screams above 3k, so I'm not crying. The AFR does look a little rich down low too, I'm thinking there may be something to that and he low rpm loss. Also seems to have used a really big intermediate jet, as stock was what, .45?
I know carb tuning is a dying art, and most here focus on ECM, so maybe there wont be a lot of input here but I thought id post anyway.
if you put up a copy of the graph, it would be easier for us to give up any insights or opinions.
m
I did. Both pages are attached to the first post. I'm looking right at them... Wonder why you can't see them on the original post. I'll try again here:
Either the dyno’s AFR measurement isn’t correct or there is some other reason for the AFR to initially start (2400) at full lean measurement (18:1) which is generally considered “air”. Then goes full rich (10:1) which should cause “blubbery” rich running.
My guess is the operator knows it and just ignores the reading down in the lower rpms or he would have done something about...
Bob
I agree with Bob and harleytuner and will add that it also looks to have an exhaust that is too free flowing. It would be nice to see the AFR for the other cylinder as well.
looks like to much accelerator pump to me. What carb is on it? Looks like it need to go up a main jet and less accelerator pump.
It's a stock CV carb. Jetting I can do, but I'll have to research adjusting the pump. Problem is as you've heard from me before there is a real shortage of good tuners in the downstate NY area. There's a guy near me who had a dynojet, and will do test pulls for me, but he plainly said he doesn't do carbs. So I can go up there with a handful of jets and try to solve this myself, but that may not have the best results...
Originally Posted by jbarr1
I agree with Bob and harleytuner and will add that it also looks to have an exhaust that is too free flowing. It would be nice to see the AFR for the other cylinder as well.
The pipe had no bungs, so the sampling is made by a sniffer tube up the pipe. Re: the flow, I ordered a "quiet" baffle from Bassani, which should introduce some more restriction. I'm trying the $70 option first, before I go the $700 supertrapp option.
If I would've read the title I would've seen it's a CV lol. Unfortunately there's not much adjustment other than AFR, Main and needle. I wouldn't go any bigger on the main or it will make it richer when it's on the accel pump. Probably not much you can do with it running a CV.
If I would've read the title I would've seen it's a CV lol. Unfortunately there's not much adjustment other than AFR, Main and needle. I wouldn't go any bigger on the main or it will make it richer when it's on the accel pump. Probably not much you can do with it running a CV.
Don't worry about it. Half of what I read, is gone before the neurons fire in my head...
Looking at the chart though, the tuner wrote he used a .58 pilot (slow) jet - which seems from everything I read, way too big. .48 is supposed to be more likely. When I asked him about it he said "whatever I wrote is what we used" so no help there.
Wouldn't an oversized slow jet contribute to excessive richness at those RPMs?
Low jet only controls up to about 1/4 throttle max. On the wide open dyno pull its using the main jet and the accelerator pump. It appears to have been running way lean when he started the run. On the dyno if you start the run at 2k RPM you hold a steady throttle at around 2k then record and hit the throttle. It looks like you were way lean coming into the run. That doesn't concern me as much because a typical carb tune you tune the main jet then go into the low speed and the needle.
05-13-2018, 04:26 PM
EVO 80 CV carb, FXR
