|
|
Post by 5speed on Nov 29, 2012 0:41:14 GMT -5
I have a Polini 70cc Evolution top end, 21mm Dellorto carb, Polini pipe.
I am having problems jetting the carb. I have the following in it:
45 Slow
105 Main
40 cutaway slide
The carb wont pull clean through from idle to top speed. When it seems rich i lean it and then it goes flat? I have alot experience with Mikuni but this is the first dellorto.
Any suggestions?
|
|
|
|
Post by 90GTVert on Nov 29, 2012 8:17:25 GMT -5
:welcome:
Get the right main jet for WOT first. Do plug chops or compare performance, whatever works best. Once that's right, then work on the rest of the settings. Pay attention to throttle position when you experience any problems to help you decide where to look.
Are you sure the CVT is setup close to where it needs to be? Sometimes with a kit that hits hard up top they will be hard to tune if the CVT isn't working to bypass the dead zone at low revs.
|
|
|
|
Post by Corrosion on Nov 29, 2012 19:37:26 GMT -5
On my stage 6 race kit / C-16 / Dellorto 21 race edition I ran the following
45 pilot, 98 main , W-7 , 50* slide. Stock Airbox with 4 vents.
I had good temps and results. Plug colors were also good on a #9 plug.
|
|
|
|
Post by 5speed on Nov 30, 2012 10:47:31 GMT -5
The main jet is good, the problem is getting the engine there. While riding at low speed and you go to WOT immediatly the engine coughs and sputters in the middle. Moving the clip does not seem to make any difference. If you go to WOT slowly it pulls just fine. I am thinking i have a mid speed needle issue or the variator as mentioned?
Thanks,
Chris
|
|
|
|
Post by cbaile5 on Nov 30, 2012 11:58:09 GMT -5
At what point is your clutch engaging? Sounds like a trans tune issue to me. I'm not sure where that kit makes power but I'm guessing it's pretty high. I would say setting your clutch to 7xxx-8xxx would help eliminate the bog and get you in the power.
Are you sure there aren't any leaks present? I'm paranoid about leaks...they've thrown my tune off in the past.
|
|
|
|
Post by 90GTVert on Nov 30, 2012 12:52:03 GMT -5
I went through something like this with even a sport kit and a pipe that should rev much less than your setup. It acted really rich until it hit. Once it hit, ran great. I had to go with lighter rollers/sliders and a stiffer contra spring and stiff clutch springs. I pretty much had to completely bypass low RPM or it just loaded up and struggled to reach the point where the pipe would hit and it would take off. WOT tuned for peak output is just too much for the engine when it's weak out of the powerband, so you have to get the clutch to engage past the dead zone and the rollers and contra spring have to be setup to operate past that dead area as well.
I'd start out with stiff clutch springs and see what happens. It's gonna take a lot of time and experimenting to find what you need. Hopefully you have a tuning roller set around.
|
|
|
|
Post by 5speed on Dec 14, 2012 15:25:16 GMT -5
? I never said there was an engagement issue? It happens when your buzzing down the road at say 50mph and go to wide open. Thats when it farts and pops. As i said i was from one extreme to the other with jetting and that didnt stop the hessitation. I am leaning toward clutching. I installed the softer Malossi engagement spring because the stiff spring was coming in around 8,00RPM and it reved to 12,000 RPM. I was told to clutch it at 11,200 RPM for my pipe and thats were the soft spring is and the engagement is a little more drivable. I have to play with the rollers to see what they effect but i beleive they are 3.8 grams each in the multivar.
I was hoping somebody was running this setup that could help?
|
|
|
|
Post by cbaile5 on Dec 14, 2012 19:26:55 GMT -5
Can you clear a few things up....
What kind of clutch are you running?
What Kind of contra spring?
What clutch springs?
Are you using a tach to tune the trans?
I find that tuning is a lot easier if you have a tach to watch the revs. With a kit like yours I'd say you probably need a medium stiffness contra spring. If you're using Malossi parts, that will be the yellow spring. Let us know all the parts you're using in the trans.
|
|
|
|
Post by Corrosion on Dec 14, 2012 21:25:33 GMT -5
You sound frustrated, know the feeling. But you need to work with what you know. If you are running @ 50MPH. Your clutch would be locked 1/1. So,are you maintaining the revs, Which would indicate your transmission is... working/ or not maintaining the revs....not working. Or is the Ignition breaking down / or fuel system limiting power. You need to provide better information, like RPM, Plug condition, ECT.
|
|
|
|
Post by 5speed on Dec 31, 2012 18:31:33 GMT -5
I am using a tach and have the maximum RPM's were they need to be at 11,200. I have the Malosi white spring in the rear and 3.8 rollers in the maloosi multivar up front and the stock gearing. Looking back, this condition started after I removed the red spring from the rear clutch and installed the softer white. I did this because it seemed like the engine was always screaming to go anywere and when coming to a stop the rear clutch was always trying to down shift (felt like engine brake)
It is definatley not ignition related but possibly when I wack the throttle open in the midrange (50 mph'ish)the clutch is loading the motor to hard and it cant take the air from wot because the rpm's are too low? I will try to work with it if it warms up here but was hoping somebody had one of these kits on here.
|
|
|
|
Post by Corrosion on Dec 31, 2012 21:10:51 GMT -5
From your last description sounds like its not down shifting / fast enough. The white spring is the likely culprit. Although you should make sure the rear pulley's slide bushing clean & lubed.
That will act the same way if its sticking.
|
|
