Help mounting 15 mm polini cp .

I'm taking advice and upgrading from sha to a polini 15 mm spigot style. I've got a mlm sha 15 mm intake but the rubber coupler I put hased fit the spigot nice and tight but not the 15 mm mlm sha intake. Can anyone give some advice on how to get a gas proof fitting to adjoin the polini to the 25 mm mlm sha intake? Thanks ppz

Re: Help mounting 15 mm polini cp .

So your intake Outer Diameter is smaller than the car OD? Is that what you're saying?

If that's the case, I'd you can weld, find a piece of pipe that slips over the intake that's roughly the same OD as the carb, and cut and weld a shim onto the intake.

If you can't weld, if you can find a brass bushing that is a very tight fit on the intake, you can hammer it on (or braze it on if you can.)

You might be able to find a stepped heater hose that fits at an auto parts store, too. (made for joining a large pipe to a smaller pipe.)

Last ditch effort would be using a smaller piece of hose as a shim, but that'll probably leak, or your carb will fall off.

Best would be to ditch the MLM intake and find one that fits

Re: Help mounting 15 mm polini cp .

Jesse Nordlander /

Machine an adapter on a mini lathe, delrin works

Re: Help mounting 15 mm polini cp .

Mark Alan /

I cut 2 inches of 7/8 handle bar and it fit semi tight over the mlm sha 15 mm intake. And it fits tightly into the rubber coupler that's on the polini spigot. Hells yes. I'm using some motoseal grey permatex sealant to help secure and seal the piece of cut handlebar letting it dry for few days and going to bolt her up to tomos alukit. I'm hoping like hell polini cp 15 mm doesn't run lean out of box. I bought selection of main jets and idle jets from treats with it. It's going to be fun. I have a used well maintained 64cc airsal for backup if things go bad. But I'm watching the plugs closely and watching temps. Polini has super nice merchandise I'm going to be cautious hopefully have fine tuned bike. Love the fact I only have idle/main jets to keep eye on . If sha can feed the alukit this new carb should.

Re: Help mounting 15 mm polini cp .

The CP is a pretty forgiving carb when it comes to jet ranges. I have four of them in different sizes, and all of them worked right out of the box.

I had to upjet a size or two on most of them for peak performance, but they never ran too lean with the stock jet.

Slow jets are usually right on, too. The only one I had to change was on a 23, because the carb was basically too big for my motor.

Don't forget the two rubber vacuum caps! Make sure those inlets are plugged if they're not hooked up to anything on your bike.

Re: Help mounting 15 mm polini cp .

Mark Alan /

Yes the two plugs are in a little package I'll put them on day of running it. I have to wait now because I cut on only handlebars I have. But a package is due in tomorrow from treats. Mlm crossbar black bonestock bars with 8 " rise. So I can't use throttle cable. I've gotta order a 40- 50 inch throttle cable to reach polini with new handlebars. Man I'm grateful for your info. Eases my mind some new to the 15 mm polini cp. I knew it had to be possible it would fuel the mild alukit. I even bought two boxes of jets with the carb. Main jets #s80 to 98. Slow jets 42 to 52. So should be a nice change from sha . I do kinda wish I would have payed closer attention when ordering and got the clamp style polini 15mm. It would of been perfect for the mlm 15 mm sha intake

Re: Help mounting 15 mm polini cp .

If I knew you were getting stuff from treats, I woulda recommended the CP quick change float bowl. It's like $15 and you can change main jets in 20 seconds.

Re: Help mounting 15 mm polini cp .

Mark Alan /

Yes I seen it yesterday. A little late now I'm broke for a few weeks. But I'll get the transparent bowl if it's not sold out by time I have the cashola. I'm going to ace hardware also. Gonna try different metal & aluminum pipe fittings until I get 1 piece to go inside the rubber coupler and fit tight over the 15 mm mlm sha intake. Then I'll be back twisted throttle again

Re: Help mounting 15 mm polini cp .

Dirty30 Dillon /

Honestly, cobbling together an intake is just about the most inadvisable thing I can imagine. Multiple materials all being held together with clamps and sealants it a sure fire way to have something loosen up and seize.

You're better off getting a pre-fab intake for this purpose that is a single, air-tight piece of steel. It's worth the ~$50

Re: Help mounting 15 mm polini cp .

DON'T get the transparent bowl unless you're running non-ethanol fuel. American fuels will melt it.

The purpose of the clear bowl is for tuning, to see if your fuel is foaming due to vibrations.

It looks cool, but pretty useless.

Re: Help mounting 15 mm polini cp .

I would not permatex that pipe onto the intake, weld it on properly and do a leak down test to make sure it’s air tight. You’re just asking for an air leak

Re: Help mounting 15 mm polini cp .

Mark Alan /

I just jumped offline with treats ordered the quick change jet bowl by polini . $17.99

Re: Help mounting 15 mm polini cp .

Mark Alan /

That's what I'm doin tomorrow. Getting 1 solid brass piece that will go on the 15 sha intake. And other end into rubber coupler coming from the polini spigot.

Re: Help mounting 15 mm polini cp .

Mark Alan /

I'm not going to half azz nothing fellas I guarantee that. I'm not wanting junk with problems. I'm gonna make sure everything is metal on metal. And reliable.

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