BBK question?

[kglazer]

would you go with a malossi cast iron bbk or a airsal aluminum bbk? the diffrence is $50. what are the advantages and disadvantages of both. i cant decide i feel like the malossi is better becasue it is MALOSSI lol. but i could just be paying for the name and i hate when i pay more because of the name

[mccanic]

cast iron is for more daily use and aluminum is more of a race cylinder. both are very nice, if the airsal has a two ring piston i would go with that.
just because its name brand doesn't mean its the best

[kglazer]

very true on the name brand. what does the double ring piston do that makes it better?

[reveeen]

what does the double ring piston do that makes it better?

It goes about twice as far (lasts twice as long). A single ring piston/set-up is "race only" (less friction) lasting about 3000 miles between rebuilds. Usually the cylinders with a single ring piston are ported a bit differently making a bit more power. A single ring tends to let the piston rock a bit more in the cylinder which may cause premature wear to the piston and cylinder.

[mccanic]

thanks reveen

[kglazer]

so if there both double ring which would you go. malossi or airsol? i want the most reliability.

[90GTVert]

I like cast iron kits for the street. One of the big advantages is that they tend to warn you that you're too lean with a soft seize. The aluminum piston will expand faster than the iron bore and eventually it will seize the engine up momentarily when it gets too hot. While this does cause some scarring of the piston and cylinder walls, it's usually fairly minor and you won't even need to do anything about it. The aluminum bore expands and the same rate as the aluminum piston, so you won't get that soft seize as a warning that you're running lean. Instead, you could end up with a hole in the top of the piston. Obviously then you need to replace the piston, and sometimes the melted aluminum can end up scuffing and even getting embedded into the cylinder walls. Aluminum cylinders use a special coating on their bores to create a harder surface. If the coating is damaged beyond scuffing it could need to be re-coated... which can cost more than a new cylinder kit. I believe that makes aluminum cylinders less friendly for the average user.

[reveeen]

malossi ........... VX319987 47mm bore Super9AC kit

You can over bore an iron kit + malossi has oversize pistons available. So what you are buying could out live the rest of the engine. Reliable enough?

Because Klymo started building scooters under license from Honda I am not entirely convinced Honda parts won't fit your scooter. I hope to get some Honda gasket scans up this week.

[kglazer]

So malossi is definitly the way to go. I will order it. What size jets should i order since i know my stock jet wil definitly be to lean for the 70cc set up

[mccanic]

if your just going with the cylinder around 85 no more then 90. good luck! post a build thread!!!

[kglazer]

Im going to order 85,87,89 jets i think that should cover me. Is there anything else i will need?
I will def make a build thread for it. Im hoping to tackle this project next weekend

[mccanic]

tuning the cvt! medium cobra spring with some 5-6g weights and you should be happy to start off.

[kglazer]

I already have a 1500 contra spring and 5 gram rollers in there now perfect!

[mccanic]

okay you might want to try heavier ones with the bbk

[kglazer]

I will start with the 5's and see how it goes. Since i dont have a tach what speed should i keep it under doring break in?